Post: June 5, 2026

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Water Features in the Home Garden

Looking to add interest to your garden, attract birds and wildlife, or drown out city noise with soothing sounds of water? Elevate your garden to the next level with a water feature. 

Kay Torrance

A water feature supplied with fresh water soon becomes its own ecosystem — especially in the hot, dry summers in the PNW. They encourage birds, frogs, dragonflies, and other wildlife into your yard. Many animals, especially raccoons, will visit for water. I have seen Cooper’s hawks make daily visits to my garden in search of prey. Hummingbirds take showers. In the spring, I sleep to a chorus of Pacific tree frogs. Water is essential to life.

There are many options for adding water features to your landscape. It is just a matter of finding a good fit and managing expectations. Options range from small to very large:

Bird Baths and Fountains 

A bird bath or fountain can add ambiance and focus to a garden. A fountain provides soothing water sounds for relaxation. Alternatively, you can have a “pondless waterfall” where a reservoir contains water out of sight. With the flip of a switch, you have a raging waterfall. Bird baths and fountains are commercially available in endless shapes and sizes, and making one can be a fun DIY project. A bird bath can be as simple as a shallow bowl filled with pebbles and water you refill daily. Vary the water depth with stones to attract a greater variety of birds. Use an automatic sprinkler system to fill it. Keep the reservoir clean, as birds need fresh water for drinking and bathing.

 
Homemade bird bath using trash can lid for the mold. Photo © Kay Torrance

Aquatic Container Gardening 

Take a large flower pot, a barrel, a livestock tank, a bathtub, or another container, and turn it into a water garden. Simply patch the holes and fill the vessel with water. Add potted water lilies or a mix of aquatic plants. It will attract birds, frogs, and dragonflies. Like a bird bath, containers need the water changed frequently to minimize algae and mosquitoes. If the container is large and heavy, make sure it has a drain plug to simplify water changes. A small filter fountain combo helps keep the water clear.

Ceramic container with water lily and papyrus. Photo © Kay Torrance

Tour the garden and check out our demonstration pond. Master gardeners will be on hand to talk about different water features and pond best practices.

Join Us for These Upcoming Master Gardener Events:

Discovery Garden
30th Anniversary Open House
Saturday, June 27 ~ 10 am – 2 pm

Talk to the people who maintain the gardens and learn more about:

• Noxious weeds
• Plant Clinic and gardening help
• Fruit trees
• Maintaining ponds and water features
• Pollinators
• Native plants for our area

Read all the details about the 30th Anniversary Open House.

__ __ __

Fire Smart Landscaping

June Know & Grow

Free. No registration required.

Presenter: Marlene Finley, Skagit County WSU Extension Master Gardener

Updated tips for keeping your home and yard more fire safe.

Tuesday, June 16, 2026 ~ 1 p.m.

Sakuma Auditorium
16650 SR 536, Mount Vernon, WA 98273

Rain Gardens

Develop a seasonally wet area of your yard with plants that thrive with wet feet. Master Gardener Carla Glassman provides the details in our blog article “Dealing with Wet Spots,” which talks about turning these areas into an oasis. The blog article contains an extensive plant list. You can also create a rain garden by capturing runoff from home’s gutters.

Ponds

Ponds can be any size, ranging from fifty to hundreds of gallons, and can feature waterfalls, fountains, or bubblers. The possibilities are endless. They can be built from prefabricated shapes or DIY custom designs dug from the ground and lined with fabric. They can be built into decks or patios and are usually stocked with plants and fish. Some gardeners prefer the simplicity of a “fishless” pond.

Creating a pond is fun but challenging. Artificial ponds can become complex, as they require plumbing and electricity for filtration, aeration, and algae control. You are creating a self-contained ecosystem, so you need to understand the chemistry you are creating. You will need to control the pH, oxygen levels, and temperature, and encourage photosynthesis. Proper planning is key, and failure can be frustrating. It requires working with nature and then continuing to tweak what you have learned. The benefits are incredibly rewarding for those who persevere. Ponds are never maintenance-free.

Maintenance Requirements – Don’t Fight Mother Nature! 

A bird bath is very simple to maintain. All you need to do is keep fresh water available daily. Fountains add a splash. Make sure to empty them at least weekly and scrub the surface with a brush to remove debris, bird droppings, and algae. This will reduce the risk of birds spreading disease and keep mosquitoes at bay.

Once you move beyond a bird bath, the maintenance requirements increase. Water features are not low-maintenance unless they are well thought out and properly designed. People who build them often give up during the first season, when the pond turns into a sea of green algae. For a pond to succeed, it is a careful balance of filtration, aeration, light, and temperature.

Filtration

Good filtration is the single most important element of pond maintenance! A good system will reduce maintenance, while an inadequate system will require cleaning messy filters several times a week. Water needs to be moving to allow biological processes to happen efficiently. Even the smallest pond needs a pump for circulation, aeration, and filtering out large debris. There are two methods of filtration, mechanical and biological. Though often discussed as alternatives, a pond needs both. 

Mechanical filters use a pump to force water through filter material, trapping solid particles. The filter medium needs to be periodically cleaned by the gardener. This process is essential to removing leaves and other debris that fall into the pond. These filters also keep the water moving and aerated, improving plant/fish health and water clarity. However, a mechanical filter will never remove all the debris from a pond, leaving some to settle to the bottom. The organic material trapped in the filter is also breaking down and, in a sense, polluting the water. This is where biological filtration comes in to transform the products of organic decomposition.

For biological filtration, you need a healthy supply of bacteria, which nature happily provides. These bacteria live on submerged pond surfaces, rocks, and even inside mechanical filters. The filter media in mechanical filters usually host a healthy community of natural bacteria, which is why you should never clean them with detergents. Just clean them with a water hose. Biological filtration needs help from a mechanical filter or pond vacuuming, as large debris (leaves) can take a long time to break down and ruin pond clarity. A bottom drain in larger ponds is essential for cleaning sediment out every few years. 

Nitrogen Cycle

Nature’s solution for removing nitrites and nitrates produced during organic decomposition is the nitrogen cycle. Bacteria feed on decomposing waste and convert it into fertilizer that pond plants can use. This is why plants are essential to a pond’s health. (See the insert on the nitrogen cycle below.) Nature was the first “chemist,” and this process depends on two types of bacteria working together. The aquatic cycle is similar to what happens in our soil, but there are some key differences. 

Aeration

A pond needs aeration, which can be supplied by a fountain, a rushing waterfall, or a dedicated pond bubbler/aerator. A waterfall or fountain filter will remove the need for a separate aerator. Submerged and surface plants also produce oxygen. Oxygen is needed by plants, fish, and the nitrogen cycle. Submerged and surface plants produce oxygen during the day, but at night they use it.  

Light, Temperature, and Algae Control

Plants need sunlight for photosynthesis. Too much light encourages algae, which is unappealing in ponds and can cause periodic pH swings that harm fish. Algae are simple plants lacking roots, stems, and leaves. A small amount of algae in ponds is normal. Algae blooms occur if there are too many nutrients in the pond. Fish can help with algae, but their waste can also encourage its growth, especially if the fish are overfed, which is common with most fish hobbyists. Surface plants steal sunlight from algae and keep the pond cooler, slowing its growth. Warm water holds less oxygen than cold water, and warm temperatures encourage algae growth, so partial sun is a good compromise for most water features. The single best method to control algae is to install a UV light to the pond’s filtration system.

Plants for the Pond

Surface and subsurface plants compete with algae for nutrients, making them great additions to a healthy pond. Aquatic plants can grow from the ground in an unlined pond, from submerged pots in a lined pond, or float on top of the water without the need for soil. (There are so many types that a separate article is needed to discuss them.) Hardy water lilies are a good choice, as their flowers and foliage enhance the pond’s beauty and shade the water while absorbing nutrients. Siberian iris (Iris sibirica) pairs nicely with lilies and grows well in partially submerged pots. Thalia (Thalia dealbata) has a tropical look but is very hardy. Many aquatic plants are tropical, like tropical water lilies, papyrus, taro, and water hyacinth. They should be treated as annuals in the pond unless you plan to remove and store them during the winter. 

Avoid reeds and rushes as they grow quickly and can take over. Make sure the plants you are considering aren’t on the state’s invasive species list. A pond may seem contained, but birds can carry seeds for miles. Duckweed is easy to establish and good at using surplus nutrients and shading water, but it can quickly get out of control and create a layer 2-3″ thick.

Keeping Fish

Koi are the classic pond fish and are prized for their color. They can live for decades and become several feet long. If you are just getting started, Shubunkins are a colorful, hardy goldfish variety that is great for a first fish. They are readily available at pet stores and do well in small ponds. Start with one to three small fish in the first year. As with plants, make sure that a fish is not on an invasive species list and is suitable for pond life. Fish require extremely clean water. They need a balanced pH. Ammonia, phosphates, nitrites, and nitrates can kill them. Before adding fish, make sure the pond has been established for at least a few months to ensure a healthy nitrogen cycle. You will need a water test kit to periodically check the water. Don’t overstock the pond with fish, and don’t overfeed them. Both will be disastrous. The fish will need to be protected from herons, raccoons, river otters, and other predators. It is best to get your pond up and running one year and add fish the second year.

Tips for Successful Water Features

Planning

• Develop a checklist for maintenance and make notes. The list will change seasonally.
• Schedule weekly routine maintenance and keep a log.

Location

• Ensure easy access to water and electricity for filtration and pumps.
• Select a spot with good sunlight if you want plants that flower, such as lilies.
• Be aware of adjacent trees that will drop leaves and branches into the pond, increasing maintenance.
• Recognize that runoff from erosion, chemicals/fertilizers, and animal waste runoff will adversely affect water quality for in-ground ponds. Adequate vegetation around the pond can help to filter the runoff before it enters the pond.

Filtration

• Ensure the system is sized appropriately for the water volume, plant, and fish load. It never hurts to oversize a system. If the filter needs cleaning more than once a week, it’s undersized.
• Choose filters that are easy to clean. Some have backwash systems like swimming pools. Some have scrapers to clean the filters without removing them. Some filters for small ponds are 3-in-1 units that combine a pump, filter, UV light, and fountain in one unit.
• Use a UV light to control algae You can get a fine-mesh filter to trap algae, but it requires frequent cleaning.
• Don’t overclean the filter. It is actually most efficient right before it clogs. That is an extreme to avoid but figure out exactly the timing between cleanings.
• Never clean the filter media with detergents, as they will kill the beneficial bacteria.

Draining

• Incorporate a bottom drain in all but the smallest ponds.
• Complete draining should only be needed every 2-5 years.

Mosquito Control

• Mosquitoes lay eggs only in still water, so if you have any circulation, they won’t be a problem.
• Fish eat mosquito larvae, so again, no problem if you have fish.
• For small water features without circulation that aren’t dumped and refilled every few days, you can use biological mosquito control, which are pellets containing bacteria that disrupt the larvae’s life cycle.

Algae Control

• Install UV lights plumbed into the filter system — hands down the best way to control algae.
• Remember to change the UV light bulb annually. (They may look like they are still working, but what you are seeing is visible light, not UV.)
• Consider other options that include barley straw, chemical herbicides, or dyes that reduce sunlight.

The Nitrogen Cycle

The nitrogen cycle is nature’s process for decomposition. The nitrogen cycle works in water similar to how it works in the ground. Use organic decomposition and fish waste as fertilizer for the pond’s aquatic plants while simultaneously keeping the water clean.

Aquatic Ecosystem
A Healthy Nitrogen Cycle Produces Clean Water

Nitrogen is the nutrient plants need most for growth. Understanding how the nitrogen cycle affects nitrogen availability helps gardeners grow healthy, productive plants while keeping nutrients where they can be used.

Terrestrial Ecosystem

Four sources of nitrogen are found in soil. Ammonium and nitrate can be used immediately by plants. Atmospheric nitrogen and nitrogen in organic material must be converted before it is useful to plants. Excessive nitrogen levels lead to runoff that can harm plants and pollute waterways. Nitrogen can also leach into groundwater. 

References and Resources

Aquatic:

Enjoying Ornamental Ponds – Louisiana State University Agricultural Center

Neighborhood and Urban Pond Management (NREM-9210) – Oklahoma Cooperative Extension Service

Aquatic Plant Selection – Clemson Extension

Ornamental Garden Pools – Alabama Cooperative Extension System

Terrestrial:

The Nitrogen Cycle. University of California, Berkley, California

Cogger, C. (Rev 2020) Soil Health. Washington State University Extension, Pullman, WA

ABOUT THE AUTHOR:

Kay Torrance has been a Skagit County WSU Extension Master Gardener since 2019. She has maintained water gardens of various sizes in different climates for over 30 years. She is the Garden Coordinator of Naturescape in the WSU Extension Skagit County Master Gardeners Demonstration Garden. She has a B.S. in Chemistry and enjoys combining science and gardening.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the Skagit County WSU Extension website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Post: May 15, 2026

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The Science Behind Plant Partnerships

It’s not magic; it is ecology in action

Rae Barto

By Rae Barto, Skagit County WSU Extension Master Gardener

Companion planting, the practice of growing different plant species together for mutual benefit, has long been part of gardening traditions across cultures. Historically, it has been framed through folklore, anecdote, and trial and error. But in the last two decades, scientific research has begun to validate, refine, and sometimes debunk these claims.

Modern researchers increasingly view gardens and farms as ecosystems rather than isolated plant beds. Companion planting is best understood as a form of polyculture, where multiple species create a more biodiverse and resilient environment. This biodiversity enhances nutrient cycling, reduces pest pressure, improves water retention, and carbon sequestration.

At its core, companion planting operates through several scientifically documented mechanisms.

Resource partitioning involves physical competition between plants. Plants with different growth habits, root depths, or nutrient requirements can coexist more efficiently than those competing for identical resources. Studies using isotope tracing have demonstrated that companion plantings access different soil layers and nutrient pools, thereby reducing competition.

Allelopathy — the chemical interaction between plants — represents one of the most studied aspects. Plants release various compounds through their roots, leaves, and decomposing matter that can either inhibit or promote the growth of nearby species. Research is identifying specific chemicals responsible for these interactions, providing a biochemical explanation for traditional planting combinations.

The attraction and repulsion of insects through companion planting is getting a lot of attention, and agricultural research proves plants produce volatile organic compounds (VOCs) that can either deter harmful insects or attract beneficial predators and pollinators. Aromatic plants can confuse or mask host plant odors, reducing pest pressure. They are typically short-range, not garden-wide.

Nitrogen Fixation: The Three Sisters and Beyond

Perhaps the most scientifically validated companion planting system is the “Three Sisters” combination of corn, beans, and squash, practiced by Indigenous peoples of the Americas for centuries. Research has confirmed that leguminous beans form symbiotic relationships with rhizobia bacteria, converting atmospheric nitrogen into plant-available forms that benefit neighboring crops.

While these benefits come primarily after the legume decomposes, planting beans next to corn (a heavy nitrogen feeder) allows the corn roots to obtain a trickle of nitrogen from the beans during the growing season. The beans utilize the corn stalks as natural trellises, while the broad squash leaves create living mulch that suppresses weeds and retains soil moisture, effects quantified through controlled field experiments.

Pruning Shrubs for the Home Gardener

May Know & Grow

Free. No registration required.

Presentor: Anne Kurt, Skagit County WSU Extension Master Gardener and Certified Master Pruner

Tuesday, May 19, 2026 ~ 1 p.m.

Sakuma Auditorium
16650 SR 536, Mount Vernon, WA 98273

Come learn some simple seasonal pruning tips to encourage the health and appearance of your garden shrubs. Learn to identify growth habit and determine the right time to prune and how. You will gain confidence and your garden will thrive.

Photo © Skagit County Master Gardener Foundation

Modern research has expanded our understanding of nitrogen-fixing partnerships beyond traditional combinations. Studies have documented beneficial relationships between leguminous cover crops and subsequent plantings with measured increases in soil organic matter and nitrogen availability lasting multiple growing seasons.

Pest Management through Plant Chemistry

Scientific investigation of companion planting for pest control has revealed sophisticated chemical defense networks. Brassicas (cabbage family plants) produce glucosinolates — sulfur-containing compounds that break down into pest-deterrent chemicals. Research has shown that these compounds can reduce populations of aphids, flea beetles, and other common garden pests when brassicas are interplanted with susceptible crops.

Beneficial Insect Attraction and Habitat Creation

Companion planting’s role in supporting beneficial insects has been thoroughly documented through field studies and insect population surveys. Flowering companions provide nectar and pollen sources that sustain parasitic wasps, predatory beetles, and other natural pest controllers through the growing season.

Research has shown that gardens with diverse flowering plants maintain higher populations of beneficial insects, leading to measurable reductions in pest damage. Studies tracking parasitoid wasp populations have demonstrated direct correlations between the presence of nectar-producing plants and improved biological pest control.

Habitat diversification through companion planting creates microclimates that support beneficial species. Research has documented how varied plant heights, leaf textures, and bloom times provide overwintering sites, hunting grounds, and nesting opportunities for natural pest predators.

Aromatic herbs like basil, rosemary, and thyme have been studied extensively for their pest-repelling properties. Laboratory and field studies have identified specific essential oils and their concentrations that effectively deter insects. For example, research has demonstrated that basil planted near tomatoes can reduce populations of hornworms and whiteflies by releasing volatile compounds such as eugenol and linalool.

Save the Date:

Discovery Garden Open House

Celebrating 30 years of education, inspiration and dedication to the community

Saturday, June 27 ~ 10 am – 2 pm
Free Admission and Parking
Discovery Garden
16602 State Route 536, Memorial Highway, Mount Vernon

Soil Health and Nutrient Cycling

One of the most significant advances in understanding companion planting comes from soil microbial ecology. Plants shape the microbial communities around the roots, and when species are grown together, these communities interact in complex ways.

Scientific studies of companion planting’s effects on soil health reveal complex underground interactions.

Mycorrhizal networks
The symbiotic relationship between plant roots and beneficial fungi, called a mycorrhizal network, can be enhanced through strategic plant combinations. Research using molecular techniques has shown how certain companion plants can expand these fungal networks, improving nutrient uptake and plant resilience.
Root exudate interactions
The carbon-rich compounds released by roots have been studied extensively, revealing how different plants can modify soil chemistry to benefit neighbors. For example, research has shown that certain plants release organic acids that help solubilize phosphorus, making this essential nutrient more available to companion plants with different root chemistries.
Carbon sequestration
The process by which plants capture and store atmospheric carbon dioxide (CO2) is called carbon sequestration. Studies have shown that soil organic matter improves with diverse plantings. Research demonstrates that polyculture systems often store more carbon in soil than monocultures, thereby contributing to long-term improvements in soil fertility and structure.

Limitations and Considerations

Scientific research also reveals important limitations of companion planting.

Allelopathic inhibition
A biological phenomenon where plants release chemical compounds (allelochemicals) into the environment that suppress the germination, growth, or reproduction of neighboring plants or microorganisms can occur when incompatible plants are grown together. Studies have documented how certain combinations can reduce yields rather than improve them.

Carrot and chive studies have shown that chives can repel carrot rust flies through the release of sulfur compounds; while differing root depths allow effective resource use. Photo © Adobe Stock

Competition
The effects of competition must be considered, as research shows that plants grown too closely can compete for water, nutrients, and light regardless of species compatibility. Scientific studies emphasize the importance of proper spacing and timing in companion planting systems.
Environmental variability
Research demonstrates that soil type, climate, and local pest populations can influence the effectiveness of plant combinations. This underscores the importance of adapting companion planting strategies to local conditions.
Evidence-Based Companion Combinations
Tomatoes and basil have been studied extensively, and research has confirmed that basil can deter certain pests.

Carrot and chive studies have shown that chives can repel carrot rust flies through the release of sulfur compounds; while differing root depths allow effective resource use.

Lettuce and tall plants demonstrate the shade tolerance principle, with research showing that partial shade can extend lettuce growing seasons and reduce bolting in hot weather.

Practical guidance:

• Focus on increasing diversity, not specific “magic” pairings. Polycultures reduce pest outbreaks and improve soil health.
• Include flowering plants to attract and support beneficial insects.
• Use legumes for nitrogen fixation and to build soil health; interplant beans, peas, or clover with nitrogen-demanding crops.
• Combine plants with complementary root systems; mix deep-rooted, shallow-rooted, and tap-rooted species.
• Use the plant’s physical structures — tall plants can support climbers or provide shade.
• Incorporate cover crops — oats, buckwheat, winter rye, and cowpeas improve soil structure and fertility.
• Focus on soil microbiology — choose combinations that enhance microbial diversity and nutrient cycling.
• Observe and adapt, local conditions matter.
• Combine with other practices, such as crop rotation and soil management.

The science of companion planting validates many traditional practices while providing a deeper understanding of the mechanisms involved. Through scientific research on plant chemistry, soil interaction, and ecological relationships, we now have evidence-based explanations for why certain plant combinations work effectively together.

By understanding the science behind companion planting, gardeners can harness these natural relationships to create thriving, resilient gardens that work with, rather than against, ecological principles. As research continues to reveal new insights into plant interactions, companion planting enables gardeners to combine traditional knowledge with modern science to create a more sustainable, productive garden.

Companion planting is a scientifically supported practice rooted in ecology, soil biology, and plant physiology. While not all traditional pairings hold up under scrutiny, many do, and modern research continues to uncover the mechanisms behind successful plant partnerships.

Companion planting works best as part of a holistic system rather than a standalone solution. Companion planting is not magic; it is ecology in action.

References and Resources

Chalker-Scott, L. (2023). Gardening with Companion Plants (Home Garden Series). Washington State University Extension.

Walliser, J. (2020). Plant Partners: Science-based Companion Planting Strategies for the Vegetable Garden. Storey Publishing, LLC.

James, D. (2014). Beneficial Insects, Spiders, and Other Mini-Creatures in Your Garden. Washington State University Extension., Pub. #EM0673.

University of California (2018). Insectary Plants, Integrated Pest Management, Agriculture and Natural Resources.

ABOUT THE AUTHOR: Rae Barto is a Skagit County WSU Extension Master Gardener, Class of 2023. Her love of plants includes anything green and growing, especially anything that can be used in cooking. She has been experimenting with companion planting for several years in her own garden. She is the coordinator of the medicinal section of the Herb Garden and is a frequent volunteer in the Plant Clinic in Burlington. 

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the Skagit County WSU Extension website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Post: May 1, 2026

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Ready to Go Shopping?

Know your yard’s microclimates before you head to the plant sale

 
Kari Ranten

Perhaps nothing thrills a home gardener more than the abundance of plants available for sale in spring. A walk through a nursery lures the gardener to marvel at beautiful perennial blooms; to desire the look, texture, and color of a tree or shrub; or to seek out the amazing native plants that call the Pacific Northwest home.

With so many beautiful choices, it’s easy to quickly fill a wagon with one (or three) of everything that looks beautiful in the moment. Before making those impulse buys, take some time to think about what will thrive in your landscape. A little homework will improve the success rate for your new plants. Research your local microclimates and keep the unique details of your yard in mind to make careful selections of the right plants for the right places – a standard master gardener mantra.

Home gardeners in northwest Washington share the Zone 8b assignment on the U.S. Department of Agriculture’s (USDA) Plant Hardiness Zone map. Type in your zip code in the map tool to learn more. This resource provides an excellent overview of plants’ overall frost tolerance and offers a broad overview of the area’s climate.

Gardeners should pair this up with localized information and knowledge of their own property.

Sunset’s Western Garden Book defines a microclimate as “a small area (such as a backyard or even a portion of it) with a slightly different climate than that of its larger surroundings. . . Plants that might not survive in a specific climate zone may grow well in the right microclimate.”

Individual yards likely have one or more unique microclimates that the home gardener should learn about and understand. Microclimates include areas of shade, sun, wind, moisture, soil, and topographic features such as elevation. In northwest Washington, proximity to rivers, lakes, and the Puget Sound also plays a role. In addition, structures, pavement, and fences can create varying conditions.

Armed with this information, gardeners can review plant qualities online or at the library ahead of time, take a list of desired plants or qualities along for the shopping trip, and make smart purchases. Once at the nursery or plant sale, shoppers will benefit from a close evaluation of plant tags (with hardiness zone compatibility and other notes for proper planting conditions) and the option to talk to the experts.

Start by doing your research

Evaluate your yard by drawing a simple map and taking notes. Observe the direction each area faces, note any low-lying areas or slopes, and learn more about the soil quality. Pay attention to the location of structures or hard surfaces that may store heat on a sunny day, creating overnight warm spots, as well as large vegetation that may bring a sphere of shade and cooler temperatures. Perform timed checks every few hours (say 9 a.m., noon, and again at 3 p.m.) during the day to monitor sun and shade patterns. Be aware of elevation and rainfall.

32^nd Annual Plant Fair Set for
Saturday, May 9 ~ 8 am – 2 pm
at the Skagit County Fairgrounds

Kick off your spring plant-buying season at the Skagit County Master Gardener Foundation Plant Fair set for 8 a.m. to 2 p.m. on Saturday, May 9, 2026, at the Skagit County Fairgrounds in Mount Vernon. The event will feature more than 10,000 plants grown or tended by Skagit County WSU Extension Master Gardeners for success in northwest Washington. More than 50 varieties of tomatoes and thousands of annuals, vegetables, herbs, perennials, trees, shrubs, berries, and more will be available. In addition, dozens of vendors will be on site with many offering plants and garden-related items. Admission and parking are free. Read the full press release>

Customers can plan ahead and prepare a shopping list by reviewing lists of plants that master gardeners will offer:

• List of tomato varieties>
• Lists of greenhouse-grown annuals, flowers, and herbs and Perennial Plant House propagated and grown perennials, trees, berries, figs and grapes>

The Skagit County WSU Extension Master Gardener Program helps our communities with their gardening needs by providing science-based education, answering plant questions, and helping with plant problems. Proceeds from the annual Plant Fair benefit the nonprofit Skagit County Master Gardener Foundation, which supports the Skagit County Master Gardener Program.

Soil tests from several locations in the yard will help you understand what your soil may need to support healthy plants.

Washington State University’s Ag Weather Net provides regional climate information from several locations in Skagit and surrounding counties about wind, temperature, and precipitation information. A home garden weather station can help gather and archive data at your specific location.

The University of California Agriculture and Natural Resources Marin County Master Gardeners provides a detailed spreadsheet to help assess microclimates and the factors to consider when planning a garden or landscape.

Another research opportunity is to observe thriving landscapes or yards in your neighborhood or community, and to visit botanical gardens in the region to see and learn about plants that thrive in the northwest environment. The 30-plus garden “rooms” of the Skagit County WSU Extension Master Gardener Discovery Garden on Memorial Highway west of Mount Vernon offer many ideas and inspiration for gardens with themes ranging from naturescape and shade to dryscape or succulents. The Discovery Garden is open daily from dawn until dusk.

Say you have a one-third-acre lot with a single-level home in central Skagit County: 

Watch the frost and snow patterns. It’s not uncommon for the north side of the house to harbor frost eight to 10 feet north of the structure for hours after the white frosty layer has melted from the rest of the yard. Snow can remain in place for days in that swath. Plants in that area must be cold and moisture-tolerant. That’s a microclimate. Well-established plants such as a June-blooming rhododendron or a David viburnum (Viburnum davidii) can continue to thrive. Adding shade-loving ferns like Asian saber fern (Polystichum neolobatum), western sword fern (Polystichum munitum), or dragon tail fern (Asplenium ebenoides) along with a couple of perennials like bleeding heart (Dicentra spectabilis) and Solomon’s seal (Polygonatum) add texture and interest in the spring and appear year over year.

Pruning Shrubs for the Home Gardener

May Know & Grow

Free. No registration required.

Presentor: Anne Kurt, Skagit County WSU Extension Master Gardener and Certified Master Pruner

Tuesday, May 19, 2026 ~ 1 p.m.

Sakuma Auditorium
16650 SR 536, Mount Vernon, WA 98273

Come learn some simple seasonal pruning tips to encourage the health and appearance of your garden shrubs. Learn to identify growth habit and determine the right time to prune and how. You will gain confidence and your garden will thrive.

Photo © Skagit County Master Gardener Foundation

The south side of the house can be quite a different microclimate. A large, south-facing patio and the house’s siding would make a true hot spot, even on warm spring days, much less on a 90-degree summer afternoon. A few plants in hanging baskets could thrive through the summer without an irrigation system. A raised bed or large pots tucked next to a south-facing wall or fence provide warmth and light reflection that tomatoes love, yielding lots of delicious fruit, steps away from the kitchen.

With careful plant selection and regular (sometimes twice daily) watering, larger pots filled with annuals and perennials can produce a beautiful abundance of color for the season. Plants with bright red and orange flowers, such as firecracker plant (Cuphea hybrid), Mexican lobelia (Lobelia laxiflora), and lantana (Verbenaceae) attract a number of pollinators including hummingbirds.

Make good plant selections. Create a list of plants that suit the landscape’s microclimates. This includes trees, shrubs, perennials, and annuals. Photos © Adobe Stock

Based on research and data gathered for your yard, you have options:

1. Make changes to manage a microclimate:

• Consider adding organic matter to improve soil moisture capacity or install an irrigation system for dry areas.
• Use raised beds for plants that need drainage and warmer soil temperature.
• Look into drains for slopes to allow water to flow in wet areas.
• Move and group plants that appreciate similar conditions.
• Protect more fragile plants with a shelter of tall plantings or a fence.

2. Make good plant selections. Create a list of plants that suit the landscape’s microclimates. This includes trees, shrubs, perennials, and annuals. Gardeners have access to a variety of resources for plant lists, including:

• Sunset’s Western Garden Book offers 30 lengthy lists with photos and plant details based on climate qualities, including sun, shade, dry areas, moisture lovers, and wind resistance.
• Great Plant Picks, the educational program of the Elisabeth C. Miller Botanical Garden in Seattle, offers many lists to support plant selections for gardeners living west of the Cascade Mountains from Eugene, Oregon, to Vancouver, British Columbia, Canada. Lists focus on drought tolerance, sun and shade, containers, and more.
• The Washington State Noxious Weed Control Board offers a printable list of noxious weeds.
• The Washington Native Plant Society provides information on invasive non-native plants that compete with native plants, plus lists on the plethora of Washington native plants that are special to Washington. 

Armed with details about your landscape, soil, light, and weather, along with a list of plants that are of interest, head out to the nursery or local plant sale with a disciplined plan to start with. Ask questions. Look at lots of plants. Make a measured selection of choices. Take those home, size up your status and, if needed, make another trip – oh, joy! The fun can stretch over a period of growing years as you watch and enjoy the maturation of your well-planned garden spaces tailored to your unique microclimates. 

References and Resources

City of Seattle Public Utilities. (2010) Natural Lawn & Garden Series: Choosing the Right Plants for a Beautiful, Trouble-Free Garden.

Elisabeth C. Miller Botanical Garden. (2026) Great Plant Picks.

McMoran, D, Huter, S. and Buller, S. (2015) How to Determine your Garden Microclimate. Washington State University Extension Bulletin FS181E.

Sunset Western Garden Book (2007) Sunset Publishing Corporation. Menlo Park, CA. 94025

University of California Agriculture and Natural Resources Marin County Master Gardeners. (2026) Garden Site Microclimate Evaluation Form.

U.S. Department of Agriculture’s (USDA) Plant Hardiness Zone Map. (2026) https://planthardiness.ars.usda.gov/

Washington Native Plant Society

Washington State University’s Ag Weather Net

ABOUT THE AUTHOR: Kari Ranten is a retired journalist and health care communicator who became a certified Skagit County WSU Extension Master Gardener in 2024.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the Skagit County WSU Extension website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Post: April 17, 2026

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The Amazing World of Geophytes

Bulbs, corms, rhizomes, and tubers: Plant ahead for joy in the future

Kari Ranten

By Kari Ranten, Skagit County WSU Extension Master Gardeners

We’re in the middle of April, and the Skagit Valley Tulip Festival is in full swing. It’s the time of year when visitors from across the globe descend on our valley to witness the marvel of acres and acres of color. Vibrant swaths of yellow, red, purple, and orange decorate the valley floor in commercial fields and exquisite display gardens.

Many home gardeners in our region also enjoy the pop of early color afforded by daffodils and tulips, and know it’s worth planting bulbs in the fall to get the reward of a spring color.

While these spring-blooming bulb plants are common to our region, home gardeners may not be as familiar with other options that start underground, such as corms, rhizomes, or tubers.

These are all geophytes, or “earth plants,” perennial plants with underground storage “containers” or systems. These underground storage containers are active and, when conditions are right, they grow, bloom, and reproduce after a period of dormancy. In general usage, all are referred to as “bulbs.”

Placing them all under the general category of bulbs, researchers note these plants have the common ability to store the plant’s complete life cycle in an underground storage structure. They all have a period of growth and flowering, followed by a period of dormancy.

The classification of these plants is based on their differing storage structures. True bulbs include tunicate bulbs (tulips) and imbricate bulbs (lilies). Corms (crocus, gladiolus), and tubers (dahlias) are referred to as bulbs, but have a different type of underground storage structure. Gardeners should pay attention to the bulb’s structure, the planting and emergence timetable, and planting recommendations to ensure blooming success.

Northwest Washington has been home to commercial bulb growers for decades, with more than 1,000 acres of tulips and daffodils grown annually in the Skagit Valley, yielding some 20 million bulbs and 75 million cut flowers.

While tulips are native to Central Asia, they were brought to the Netherlands by botanist Carolus Clusius in the late 1500s. Dutch immigrants to the Skagit Valley saw the potential of a maritime climate similar to Holland’s and began growing tulips and daffodils for commercial purposes in the 1940s and 1950s.

There are, however, many native bulbs in the region. The Puget Sound Chapter of the Washington Native Plant Society lists varieties of allium, lily, camas, iris, and hyacinth as native bulb plants. (See References and Resources.)

For the Love of Hummingbirds: The Ecology of Anna and Other Hummingbirds

April Know & Grow

Free. No registration required.

With Greg Green, senior instructor at Western Washington University

Tuesday, April 21, 2026 ~ 1 p.m.

Sakuma Auditorium
16650 SR 536, Mount Vernon, WA 98273

Want to learn more about hummingbirds and the ecology surrounding them?  WWU Instructor and wildlife biologist Greg Green has been studying hummingbirds for more than a decade. His presentation will include the story of the Anna’s hummingbird march north over the past 75 years. Come hear about  this fascinating relationship between plants and animals.

Photo © Greg Green

True Bulbs: 

Planted in fall as soil temperature drops to 60° F, September to December, daffodils and tulips lead the way for spring-blooming bulbs. Crocus, hyacinth (Hyacinthus orientalis), grape hyacinth (Muscari armeniacum), snowdrop (Galanthus nivalis), and ornamental onion (Allium) also fit into this category.

The structure features a basal plate, or the bottom of the bulb where the roots grow; flesh that shows storage “rings;” skin that covers the outside; and the “shoot,” where the developing flower and leaves begin.

Plant spring bulbs two to three times as deep as the bulb is tall. For most larger bulbs, such as tulips and daffodils, they are planted about eight inches deep, while small ones, such as crocus, are planted three to four inches deep.

Forgot to plant your bulbs? While not ideal, it’s still OK to get them in the ground in January or even February if the soil isn’t frozen.

Spring-blooming bulbs are winter hardy. After the plants bloom and die back, they typically need no attention before repeating the perennial cycle in the home landscape. Bonus about daffodils: They are deer and rabbit-resistant.

Summer-blooming gladiolus grow from corms which have a swollen base and should be arranged in the soil with buds protruding up. They are planted in the mid-spring after danger of frost has passed. Photos © Adobe Stock

Corms:

Plants that grow from corms include gladiolus, crocus, and freesia. The structure is solid and features a swollen stem base. Somewhat similar to bulbs, they lack the layers of flesh and covering. Spring-blooming crocus are corms, but fall-blooming crocus are not true crocus but a bulb in the lily family.

Gladiolus corms can be dug in the fall, separated, and stored for replanting, though many gardeners in our area can leave them in the ground with minimal or no loss.

Dahlias grow from tuberous roots which have buds or eyes near the crown. Photos © Adobe Stock

Rhizomes

Plants developing from rhizomes, such as lily-of-the-valley (Convallaria), canna lily, and iris, grow horizontally under the soil’s surface, which can result in the plant spreading.

Though not strictly botanically classified as rhizomes, the fleshy roots of daylilies and peonies appear very similar and are sometimes referred to as rhizomes and/or tubers. The roots of these plants can store nutrients. Peony root clumps should be divided in the fall, while daylilies can be divided in the spring or fall.

Depending on your USDA zone, summer bloomers may not be winter-hardy. Each bulb type has specific spring planting requirements for timing and depth, based on the last frost-free date in your zone.

Lily-of-the-Valley and bamboo both grow from another type of geophyte called rhizomes. These rhizomes can spread easily underground and can be managed with annual maintenance. Read our blog article growing bamboo Photos © Adobe Stock and Kay Torrance.

Tubers and Tuberous Roots

Caladium, Oxalis, Gloriosa, ranunculus, and anemone are all grown from tubers.

Structurally, a big difference between tubers and true bulbs or corms is the absence of a basal plate where roots develop or a tunic covering. They have “eyes” where the new plant will grow.

Dahlias fall into a slightly different category called tuberous roots. The plant’s energy is stored in an actual root, and it forms growth from buds at the top of the root or the base of the stem. Dahlias can be dug up in the fall and saved for planting the following spring, normally mid-May in northwest Washington. Other tuberous roots include all types of potatoes and daylilies.

This group of perennial plants, called geophytes-has the unique ability to store energy in their underground “storage containers” and burst forth with beautiful flowers throughout spring, summer, and fall. Identifying them as bulbs, corms, tubers, or rhizomes, helps a gardener understand what is required for successful growth. 

References and Resources

Bulbs, Corms, Rhizomes and Tubers. (2026) Penn State Extension.

Pokorny, K. (2025) Plant spring-blooming bulbs in fall for years of low-maintenance color. Oregon State University Extension.

Streich, A., Janssen, D., and Cue, K. (August 2007) Spring Flower Bulbs. University of Nebraska-Lincoln Extension, Institute of Agriculture and Natural Resources.

What is a Geophyte? (2024) Coastal Gardener. University of California Agriculture and Natural Resources.

Bulbs. (2026) Backyard Farmer. University of Nebraska-Lincoln Extension, Institute of Agriculture and Natural Resources.

Easy to grow native bulbs you should grow now. Washington Native Plant Society. Native Bulb Information

ABOUT THE AUTHOR: Kari Ranten is a retired journalist and health care communicator who became a certified Skagit County WSU Extension Master Gardener in 2024.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the Skagit County WSU Extension website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Post: January 3, 2026

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Phenology in Nature

Studying nature’s cycles and signals for greater understanding in the garden

By Kathy Wolfe, Skagit County WSU Extension Master Gardener

 
Kathy Wolfe

Birds migrate, plants and flowers bloom, certain insects appear, frost arrives, leaves bud or fall, all as part of our seasonal year. The garden does not pace itself to our calendar. Spring may come early one year and later another. By reading certain biological phenomena, we can accurately predict when to plant particular plants, when to worry about the arrival of unwanted weeds and insects, and when to protect our plants from frost.

Phenology is the study of the periodic events in biological and animal life cycles and how seasonal and interannual variations influence them. It is an ancient craft used by our ancestors to manage their lives and their crops successfully and uses natural indicators to read the progress of climatic cycles. Without the ability to learn from and act upon clues taken from seasonal changes, human survival could be jeopardized.

The word phenology comes from the Greek “plaino” meaning to show or appear. It is the study of the timing of biological events in plants and animals, such as flowering, leafing, hibernation, migration, and reproduction.

The Chinese are thought to have kept the first written records dating back to 974 B.C. Early indigenous peoples determined that corn should be planted when the oak tree leaves were the size of a squirrel’s ear. Early settlers in Kentucky noted that green peas should be planted at apple blossom time. Some say the unique call of the whippoorwill is saying, “Plant your peas! Plant your peas!” Northern farmers found that Irish potato yields were best when planted as dandelions began blooming in open, sunny spots. Dandelion blooms also indicated planting time for beets and carrots. Other time-honored correlations included planting hardy crops such as asparagus, rhubarb, horseradish, and strawberries when peach and plum trees bloom; planting perennials when maple leaves emerge from buds; watching for lilac bloom to plant squash and beans, and pruning roses when forsythia blooms. Some famous historical figures who recorded their own phenology observations include Thomas Jefferson, Aldo Leopold, and Henry David Thoreau.

Many seasonal events in animals and plants are tightly tied to temperature. Other environmental variables, such as day length, available moisture, and water temperatures, frequently play a role. Global changes, such as urbanization and habitat fragmentation, also shape phenology. Plants and animals use a combination of these to determine their breeding, migration, bloom, and other life cycles to thrive.

If two species require the same combination of factors, these cycles coincide. Migration or breeding could occur later in a cool spring year and earlier in a warm one, but they have always appeared together. So, when a caterpillar emerges and needs leaves to eat, or when chicks hatch and need caterpillars, those foods are available to them at the right time. A balance is established, and a cycle begins. When plants and their pollinators become mismatched, both parties suffer. Plants lose their pollination services, and pollinators lose their food source.

Extensive phenology data is collected from the ancient archives of Asian monks, farming records from the seventeenth, eighteenth, and nineteenth centuries, biological records that study preserved, pressed plant collections from early explorers, almanacs, meteorologists, satellites from around the world, nature journals, and even old photographs. Comparing this information with our current records concludes that springtime is arriving earlier and global temperatures are rising. As temperatures rise earlier, trees leaf out, flowering, and fruiting advance.

Autumn patterns are not as easily chronicled as those in spring because events such as leaf color change and leaf drop can be affected not just by temperature but also by day-length and available moisture. In general, these autumn events are shifting later in the year. Globally, some animals are also changing their breeding season and migratory patterns.

This information is fascinating, but how does this affect me? Some changes that may occur are:

At the grocery store
Crop success depends on many factors, including daily temperatures, rainfall, extreme weather events, and the presence of pollinators, pests, and diseases, all of which farmers track and use to make decisions on sowing and harvesting, fertilizing, optimizing disease and pest management, and crop rotation. How farmers adapt to these changes affect crop availability and pricing.

Other ramifications include if fruiting plants like blueberries, cherries, and apples bud out early and the last frost hits, the tender plant tissue may be exposed to freezing temperatures, jeopardizing fruit production.

Many fruit and nut trees, such as pears, peaches, plums, walnuts, almonds, and pistachios, require exposure to a winter chilling period to produce a large quantity of fruit. Extremely warm winters can affect their fruit yield and quality.

In springtime, if plants are cued by warmer temperatures to leaf out and bloom earlier, and insects use day-length as an indicator for hatching, mismatches in the species’ interactions for pollination are significantly reduced, and seeds are less likely to form.

Longer growing seasons and our health
To those allergy sufferers out there, you are not imagining that you are having stronger and longer reactions year-to-year. Since 1990, the pollen season has lengthened by more than 20 days in the U.S., and the amount of pollen generated by wind-pollinated plants has increased by about 20%. 
Milder winters and a longer growing season
We gardeners are all in favor of a longer growing season. Unfortunately, these conditions also foster early emergence and longer life-cycles for disease-carrying insects such as ticks, which transmit Lyme disease, and mosquitoes, which transmit dengue, West Nile virus, encephalitis, and malaria.

Waterborne illnesses from warmer, fresh, and marine waters promote the growth of harmful bacteria, algae, viruses, and parasites. These are but a few of the changes observed in both the biological and animal worlds due to longer springs, as noted in current phenology data. 

Phenology is a valuable tool for understanding the interconnected relationship between living organisms and their environment. Knowing changes in data helps monitor climate change, support agricultural planning, support wildlife management, monitor ecosystem health, and support cultural practices. Even as nature is beginning to adapt in some areas, it is important to watch, record, and learn to make the best decisions moving forward.

If you are intrigued about what is happening in your immediate environment, it is simple to start your own adventure into phenology. Begin by observing, taking notes, and tracking events in your garden or yard year-to-year. Common examples include the dates when migrating birds return, the first flowering dates for plants, and the dates when a lake freezes in the autumn or thaws in the spring. Notice the duration of events and connect them by using simple knowledge. Use the information you gather to plant your garden using natural cycles. You will learn more about your world and the beautiful intricacies of nature than you ever imagined.

To participate further in the phenology adventure, go to the USA National Phenology Network Nature’s Notebook project and become involved. You can watch a YouTube video on what this involves on their website listed below. For a deeper dive, read University of Arizona Associate Professor Theresa M. Crimmins’ new book Phenology, part of the MIT Press Essential Knowledge series.  

Resources for more information:

Crimmins, T. (2025) Phenology MIT Press Essential Knowledge series

USA National Phenology Network.

“Monitoring phenology on the National Wildlife Refuge System” UWFWS Phenology Network – a collaboration between the United States Forest and Wildlife Service and the USA National Phenology Network.

Karns, G. (2022) “The Ohio State Phenology Calendar: Understanding Nature’s Biological Clock”, Ohio State Maple publication, The Ohio State University College of Food, Agricultural and Environmental Sciences.

Project Budburst, Chicago Botanical Garden, Regenstein School.

Delahaut, K. (2012) “What is ‘Phenology” University of Wisconson-Madison, Wisconsin Horticulture Division of Extension.

ABOUT THE AUTHOR:
Kathy Wolfe has been a Skagit County WSU Extension Master Gardener since 2002. She is co-manager of the vegetable garden at the Discovery Garden on SR 536 west of Mount Vernon.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the Skagit County WSU Extension website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Post: November 7, 2025

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Compost structures combine science, nature, and art

How to take an artistic approach to compost structures

By Kari Ranten, Skagit County WSU Extension Master Gardener

 
Kari Ranten

Showing home gardeners how to compost yard and garden waste successfully is a cornerstone of the teaching priorities embraced by the WSU Extension Master Gardener program. It’s an age-old concept of allowing naturally occurring microbes to convert leaves, grass clippings, and other garden materials into a soil amendment and home for beneficial insects, worms, and other creatures.

“Gardeners have used compost for centuries to improve their soil and help plant growth. Incorporating compost into light, sandy soil helps it hold both moisture and nutrients, while adding it to heavy soil improves drainage.” (Rosen et al. 2018).

About Master Gardener Herta Kurp

Herta Kurp has served as a Skagit County WSU Extension Master Gardener volunteer since 1995 and, in addition to helping lead the composting program, is responsible for many of the creative installations throughout the Discovery Garden. Her projects include the archways at the main entrance and northwest corner of the garden; the plant house shade structure; a tall fence camouflaging the greenhouse and various benches, trellises, fences, and gates to individual gardens.

She also created the design for the dogwood sculpture near the main entrance, which was fabricated by the Skagit Valley College 2022-23 Weld Club. She also designed and helped construct the new worm chalet at the Skagit County WSU Extension office. Kurp grew up in Germany, where she developed a deep appreciation for agriculture and the environment. She studied architecture, came to the United States while in her 30s, and owned her own architectural firm specializing in residential design. Her latest projects have focused on building creative, attractive, and small-scale compost structures in the garden.

The process also reduces the burden on the environment. “Composting reduces the flow of wastes to landfills or burn piles and produces valuable organic matter for the soil at the same time… Composting is a simple, yet important way to improve our communities and the environment.” (Cogger et al. 2017)

Despite the proven benefits, a compost pile may not be the homeowner’s favorite thing to tend to or look at all year long. Gardeners often contain compost in an enclosure using wire or wood fencing, cement blocks, bricks, or a commercially available bin to prevent the materials from spreading or blowing away.

The good news is: There are more artistic options. The Skagit County Master Gardeners’ Discovery Garden provides examples of small-scale composting structures that take an attractive and creative approach, thanks to longtime Master Gardener Herta Kurp.

Kurp has been involved with the Discovery Garden since the mid-1990s, before trees were planted and structures built. She helped shape the plan and built environments of the garden and led the composting program. Until the past couple of years, a centralized system of bins was in use to support composting for the entire 1.5-acre garden.

More recently, Kurp and other master gardeners have started to explore the use of smaller composting stations within the 30 different garden “rooms” at the garden. So far, about 10 percent of the material generated for compost has been redirected to the individual gardens’ smaller compost stations, creating efficiency and points of interest.

Know & Grow

Creating Outdoor Holiday Arrangements

Free, no registration required
Just in time for the holiday season, Skagit County Extension Master Gardener Karen Bruce will demonstrate how to create a festive outdoor container display using a variety of readily available greenery and berries from the landscape, such as evergreen branches from fir, pine, cedar, spruce, and other greenery. If you have greenery to share with others, you may bring some along for attendees to take home for an arrangement.

Join us for this free, pre-holiday event!

Tuesday, November 18, 2025 – 1 pm – 2:30 pm

NWREC Sakuma Auditorium 16650 State Highway 536, Mount Vernon

At the Discovery Garden, Kurp has always focused on her keen interest in composting, permaculture, and caring for the environment, while also nurturing her creative side through hands-on design and building structures. The outcome is the development of a series of informal “habitat heaps” within individual gardens that carry an artistic flair, using materials readily available within the garden.

Kurp collects items pruned from the garden during routine maintenance and uses those supplies to construct interesting compost structures that blend into the garden landscape. Twigs, vines, branches, and raspberry canes are turned into small-scale compost piles, creating a natural, artistic look that blends into the landscape. This approach supports the insects, birds, and other creatures of the garden, is less expensive, and more attractive.

© Kari Ranten

“This stirred my imagination and creativity,” she said. “We can use all of the materials that would go into a burn pile or compost. The structure itself is organic and can become compost in the end.”

In the Meadow area of the Discovery Garden, a tall structure built of larger branches complements a nearby 15-foot tree snag that was intentionally left to support the environment. On a late spring day, a fledgling robin took a break on the compost structure during an early flying lesson. 

In other areas, a teepee shape is built and enhanced with wreaths made of dogwood branches that are pliable when first pruned and easily fashioned into a circle.

“It becomes a part of the personality of the garden and every season it looks different,” Kurp said of the natural structures. “In winter, the structure comes to the fore, like the skeleton of the garden. In other seasons, it blends more into the surrounding growth, providing a screen for the compost pile.”

The artistic compost piles have a serious, science-based task, but also create “whimsical, playful” shapes in the garden, she said. “We have some nice examples, and it’s a good demonstration, which is what we are all about at master gardeners. It’s an invitation to be creative in the garden in a new way.”

Visit the Discovery Garden, which is open to the public daily from dawn until dusk, to see examples of a variety of composting options:

• The creative compost structures made of branches, twigs, vines, and stumps can be found in Naturescape, the Children’s Garden, and the Meadow.
• The main, centralized compost station features a series of bins where master gardeners separate branches and green material, which is chopped into smaller pieces to expedite organic breakdown. Interpretive signs provide information, and master gardener volunteers are often on hand on Tuesday mornings from March through October to explain the process.
• A few small, classic wire enclosures are tucked into individual gardens, including one along the path in the Fall/Winter garden with explanatory signage that showcases the different colors of the layers of compost as it breaks down, with the dark mulch at the bottom and the latest additions on top.

Resources:

Resources readily available about how to get started with home composting; the benefits, different methods (including hot and cold), and storage structures include:

• Skagit County Public Works Solid Waste Division’s Home Composting
• University of Maryland: How to Make Compost at Home: 
• University of Minnesota Extension’s Composting in Home Gardens.
• Washington State University Extension’s Home Garden Series: Backyard Composting

References:

Cogger, C., Sullivan, D., and Bary, A. (2017) Backyard Composting. Washington State University Extension. Publication #EB1784E.

Rosen, C., Brown, D., Mugaas, R. and Halback, T. (2018) Composting in Home Gardens. University of Minnesota Extension.

Shell, L. (2020) How to Make Compost at Home. Based on HG 35 Backyard Composting. University of Maryland Extension

ABOUT THE AUTHOR:
Kari Ranten is a retired journalist and health care communicator who became a certified Skagit County WSU Extension Master Gardener in 2024.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the Skagit County WSU Extension website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Post: October 17, 2025

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Conifers in the Homescape

Selecting and caring for conifers will provide year-round beauty and function

By Alison Hitchcock, Skagit County WSU Extension Master Gardener

Alison Hitchcock

Conifers make a valuable addition to any garden, providing a variety of landscape uses: hedging, windbreaks, ground covers, or specimen focal points. They provide year-round color, texture, and a range of appealing attributes. Once established, conifers require very little care, rarely need fertilizer, resist most insects and diseases, and pruning becomes an optional task.

The term conifer is derived from the Latin words “con” and “ferre, referring to the cone, and the term “to bear”. Broadleaved trees such as holly, laurel, or eucalyptus reproduce with flowers and fruits; conifers reproduce through cones. Both pollen (male) and seed (female) cones are formed; all are wind-fertilized. Most conifers are monecious (Greek, one house) with male and female cones occurring on the same tree, but several genera are diecious (two houses). The age at which a conifer bears cones varies, but it usually takes at least 10 years before cones appear. Maturation can vary from 1 to 3 years. Some dwarf varieties never develop cones.

Know & Grow Series:

Conifers in the Home Landscape

Free, no registration required
Listen to Master Gardener Alison Hitchcock speak on caring for conifers in the home garden. Alison Hitchcock has been a Skagit County WSU Extension Master Gardener since 2001. Prior to retirement, she worked for the Department of Natural Resources as the Northwest Regional Silviculturist.

Tuesday, October 21, 2025 – 1 pm – 2:30 pm

NWREC Sakuma Auditorium, 16650 State Highway 536, Mount Vernon

While the majority of conifers are considered evergreen (foliage retained more than one growing season), there is a small group of conifers: larch, bald cypress, and dawn redwood that lose their needles every year, i.e., deciduous. Despite the term, conifers do not keep all their leaves indefinitely. Needles become less efficient as they age, accumulate surface debris, and receive lower levels of sunlight due to interior foliage. These unproductive leaves are shed over time, though the needle life span will vary by species. Pines rapidly shed needles every 3-4 years; spruce and fir needles turn yellow and drop gradually; yews turn yellow and drop in the late spring or early summer of their third year. Sequoias, redwoods, and arborvitae shed small branchlets. We witness the flagging of western red cedar each autumn as older foliage dies.

Tree and Site Selection
When selecting a conifer, there are several things to consider: function, size and space needs, sunlight, and soil needs. Numerous cultivars of all shapes and sizes are available from local nurseries and garden centers to meet the needs of your garden design.

A cultivar represents a deviation from normal characteristics common to a species. Though some cultivars are the result of human hybridization, most cultivars arise from mutations that give rise to dwarf and giant forms, variegated foliage, weeping, and prostate habits. If the unique traits are maintained over multiple generations, plant biologists can give a cultivar a new name and propagate it through grafts and cuttings.

When selecting a conifer, one must anticipate the tree’s mature size and space needs. The American Conifer Society has established four size categories for conifers: Miniature, Dwarf, Intermediate, and Large, to aid in landscape design. Once established, growth may vary slightly due to local environmental conditions, but registered cultivars should maintain their described size. It is essential to note that any conifer will continue to increase in size at the stated rate beyond 10 years. If your tree becomes too large, corrective measures are limited to perpetual pruning, relocation, or removal. In most cases, severe pruning will destroy the conifer’s natural charm, although some plants may recover over time. Often, removing and replacing a large tree is easier, although removal can be costly.

Shade and soil conditions can be particularly important when selecting the right conifer. Shade-tolerant species are able to thrive and reproduce under low light levels, while intolerant species require full sunlight and little or no competition. Most conifers prefer full sun and evenly moist, well-drained, neutral to acid soil. The few species that tolerate wet soils include Atlantic white cedar, dawn redwood, and some spruces. Drought-tolerant species include juniper, cypress, and pine.

Pruning and Shearing
The pruning needs of conifers are minimal if plants are chosen to fit their allotted space. Always prune a conifer for a particular purpose: removal of diseased or dead wood, control of size, and control of shape. Though the techniques sound similar, there are essential differences between pruning and shearing. Pruning refers to the selective removal of branches for the health and proper size of a plant. Shearing removes foliage to create a uniform surface or shape without regard to branch structure. Pruning cuts encourage growth throughout the plant, while shearing is generally limited to the current year’s growth.

Pruning of Douglas fir leader. Developing Quality Christmas Trees in the Pacific Northwest © Oregon State University Extension | Chad Landgren

Pruning Whorl-branched Conifers
(Douglas fir, spruce, true fir, true cedar, pine)

Whorl-branched trees will not form new buds on old wood, so do not cut back to the brown, aged stems. To control height or branch length, always cut back to a side branch or dormant bud. Pruning the outermost branch tips back to a bud will also encourage fullness. For a formal shape, shear in summer after new growth has expanded but before new buds form in the fall. To replace a lost leader, support the uppermost lateral branch to a vertical position with a splint and remove after one growing season.

Unlike other whorl-branched conifers, a pine’s current year’s shoots (candles) should be pruned in late spring. To slow growth or produce a more compact shape, pinch one-third to one-half of each candle; to maintain size, remove most of each candle. Shearing is not recommended for pines.

Pruning Random-Branched Conifers
(Juniper, Arborvitae, Chamaecyparis, yew, hemlock)

Pruning to maintain shape is best done in early spring so that new growth covers the cut ends. Snip branch tips back lightly. Hand pruning rather than shearing creates a more natural shape, but plants can be sheared in early summer once the tree stops growing.

Sheered topiary Photo David McElwee | Pexels.com

Yew and hemlock are exceptions to most conifers in that new growth will develop on old wood, and they are forgiving of poor pruning and very suitable for hedging. To maintain size, prune in late winter or early spring before new growth begins. Avoid trimming the tops of hedges until the desired height has been reached. If shaping for fullness or a formal hedge, lightly trim back the outermost new growth using hand pruners or hedge shears. Shearing of new growth can continue into early summer.

Incorporating conifers into your garden design not only enhances visual interest but also promotes a resilient landscape with minimal upkeep. By carefully considering their size, light, and soil requirements these remarkable plants can thrive in your garden. Whether used as hedges, focal points, or ground covers, conifers will provide lasting beauty and functionality to your outdoor space. 

When to prune or shear is mainly dependent on conifer branching patterns, either whorl-branched or random-branched. Whorl-branched (determinate) conifers put on one flush of growth each spring. Buds at the tips of the tree flush in the spring, elongate until sometime in July, and then set new buds in the fall for the following spring. Random-branched (indeterminate) conifers produce new growth from buds at the tips of the branches and from dormant buds further back on the stem than the whorled-branched species. The result is that random-branched conifers can be cut back more severely and still produce new growth.

General guidelines for pruning:

• Remove dead, diseased, or broken branches anytime.
• Prune all conifers, except pine, before new growth starts in the spring or during the semi-dormant period in mid-summer after growth has stopped.
• If shearing, begin in late spring or early summer after new growth begins.
• Do not prune evergreens in late summer or early fall; new growth will not harden off and will be subject to winter injury.
• Do not prune into the inactive center because new branches will not form to conceal the stubs.
• For prostrate or open-grown trees, selectively prune individual branches rather than shearing the whole plant.

Resources and References:

American Conifer Society, accessed April 25, 2025, 

Welch, H., (1966) Dwarf Conifers – A Complete Guide. Charles T. Branford Company, Newton, Massachusetts

Landgren, C. (2025) Developing Quality Christmas Trees in the Pacific Northwest, Oregon State University Extension. 

Bird, R. (1994) Ornamental Conifers. Quintet Publishing Limited, London, UK.

Hartman, J., Pirone, T., and Sall, M. (2000) Pirone’s Tree Maintenance. 2000. Oxford University Press, New York, NY.

ABOUT THE AUTHOR:
Alison Hitchcock has been a Skagit County WSU Extension Master Gardener since 2001. Prior to retirement, Alison worked for the Department of Natural Resources as the Northwest Regional Silviculturist.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the Skagit County WSU Extension website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Post: October 3, 2025

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Getting Your Garden Ready for Winter and Beyond

A fall checklist to prepare for next season’s success

 
Diana Wisen

By Diana Wisen, Skagit County WSU Extension Master Gardener

It’s been a lovely summer for gardening and your landscape may still be going strong, but the soggy, overcast days will soon be here. One late October morning you will wake up and your glorious dahlias are a black slimy mess, signaling our first frost occurred overnight. In our area, the first frost usually occurs around Halloween. With this, our dry summer and fall weather will come to a close, opening the door to November, often the rainiest month of the year here.

With the first frost most likely less than a month away, there is much you can and should do in your garden this time of year.

1. Assess Your Entire Landscape and Make Notes

Take a cup of coffee or tea and your camera and walk around your yard. (This is not the time for wine.) Ask yourself what is doing well? What do I like? What is not doing well? What don’t I like? What’s okay but could be better? What am I tired of? Is there anything I want more of such as color, shade, flowers, or that I want less of? What needs significant maintenance, pruning or removing? Think about rejuvenation, renovation, or no changes. Just seasonal maintenance? Don’t put them off. Now is the time to start dealing with your ideas.

2. Fall is a Good Time to Plant

Plant more flowering spring bulbs. Next spring you will be so glad you did. And most will naturalize and multiply over the years. If you have a deer or squirrel problem you will want to take precautions to protect some kinds of bulbs. This is the best time of year to plant perennials, shrubs, and trees. The ground is still warm enough for the roots to begin to grow. It may take at least a year or two for the roots of shrubs and trees to become fully established, which means they are able to take up enough water and nutrients to sustain the shrub or tree. When planting, dig a wide shallow hole. Set the plant in at the same level as the soil around the trunk (or a little higher). Refill the hole with the same soil you dug out. Water well to settle it in. Water regularly for the next year or two. Mulch with arborist chips about three-inches deep but not touching the stem or trunk.

3. Weed. Weed. Weed!

Pacific Northwest weeds are super survivors. That’s one reason they are weeds. Many tend to grow year around and set thousands of seeds that can last for years. The cool season weeds such as shot weed (aka hairy bittercress) are beginning to germinate and the summer weeds are still going strong. Dig out weeds while they are small, before they flower, and especially before they set seed. This is particularly true for the vegetable and annual flower beds. If not tended, weeds can overpower next year’s crops before they can get established.

4. Mulch

There are several reasons to mulch. It helps keep soil moisture stable, and prevent erosion and soil compaction. It thwarts weed seeds already in the soil from germinating. Using a plant-based mulch such as arborist chips or compost slowly adds organic matter and nutrients to the soil and can make the landscape look attractive. Wait until there have been some thorough rains before putting down the chips. Save your homemade compost to put around your perennials and roses to slowly feed them over the winter. Some bagged or commercial compost may have very little nutrient content (read the labels!) and is best used as soil cover or conditioner.

5. Help Your Soil

A wide variety of soil types and conditions can be found throughout Skagit County. Before amending your soil, have your soil tested. Without knowing what your soil needs, additives could be wasteful, harmful, and expensive, as well as just not needed. Local native soil tends to be on the acidic side with sufficient levels of phosphorus. Too much phosphorus actually causes problems. Adding organic matter such as homemade compost is a good way to enrich the soil. You do not need to add a lot-2-5% compost by volume is sufficient. Rain will leach out the nitrogen, so wait until spring to put it on your vegetable area.

Place interesting wire towers throughout your garden to make easy disposal of leaves for composting over winter. © Skagit County Master Gardeners

6. “Leave the Leaves”

As you cut back plants at the end of the season, leave the stems and leaves in place on the ground. By doing so, you are providing food for soil microorganisms, which is the beginning of the food web. They in turn provide food for insects that become food for birds and other small creatures.

As you clean up the garden, you may find diseased plant materials. Do not leave this in the garden or put it in your compost bin or pile. Put diseased plant stems and leaves in your garbage or commercial yard waste bin. Disease spores and microorganisms will overwinter in the soil or in a home compost pile. Pick up dropped and rotting fruit from under trees and handle the same way.

If you have an abundance of leaves in the yard, you can pack the slightly damp deciduous leaves into large black plastic bags and let them sit for a year or two. They make leaf mold, often called “black gold” by gardeners because of its excellent compost quality. For more info on improving your soil’s health see > Master Gardener Soil Health Tips

Know & Grow: Conifers in the Home Landscape

Free, no registration required
Listen to Master Gardener Alison Hitchcock speak on caring for conifers in the home garden. Alison Hitchcock has been a Skagit County WSU Extension Master Gardener since 2001. Prior to retirement, she worked for the Department of Natural Resources as the Northwest Regional Silviculturist.

Tuesday, October 21, 2025 – 1 pm – 2:30 pm

NWREC Sakuma Auditorium
16650 State Highway 536, Mount Vernon

7. Pruning
Generally fall is not a good time to prune except for the 4 D’s–Prune out the dead, the diseased, the damaged, and the dys-functional (or deranged?) anytime of the year. However, pruning healthy plant material in the fall tends to encourage new growth, which you do not want during the colder months ahead. Tender new growth is much more susceptible to cold and wind damage. Pruning now might also cut off the flower buds of next spring’s flowering shrubs. If in doubt about when to prune flowering shrubs, a good rule is to prune right after a plant has bloomed, and not yet set next year’s flower buds. Roses are best pruned in late March, though you can cut back a bit the tall floppy canes of grandifloras now.
8. Lawn Care
Fall is also the best time to fertilize a lawn. Always read and follow the directions on the bag. Don’t use a Weed ‘n Feed until absolutely needed. A few weeds in a lawn are fine and can be dug out with a kitchen or Hori Hori garden knife if they bother you. Some people even plant crocus in their lawn for spring blooming.
9. Winter is Knocking
Water. Before you unhook your hoses make sure those big shrubs under eaves or large trees are well-watered. Rain may not reach their roots. Shallow rooted big rhododendrons can get quite thirsty in the fall.

Bring in tender plants and containers. Plants in containers could freeze and die because their roots are above ground.

Dig and store summer blooming bulbs, or take your chances on their survival.

Wrap arborvitae hedges with plastic deer fencing if you expect to get heavy snow. If you think a shrub or tree may have died during the winter, wait until June to dig it out. It may come back, just slower. Scrape and test for green tissue to see if it is still alive lower down.

10. Take Care of Your Tools and Equipment
Good, high-quality tools make gardening easier and more productive. We often have more than one pair of shears or shovel, using different sizes for different tasks and users. Take the time to clean and sharpen them. A freshly sharpened shovel or hoe is so much easier to use. Sharp pruning shears and loppers make it fun to prune. Do not use bleach as it corrodes the metal. Read our blog post on Tool Care and Maintenance
11. Refresh a Container for Seasonal Interest.
Stick some branch greens in a bucket or vase and put in a container. Add some seasonal plant material such as berries, pansies, leaves, colorful branches, pumpkins, or whatever you have in your yard. Do one for your front door and your back door. You deserve to look at nature’s beauty every day.

Have more fall plant or gardening questions? WSU Skagit County Master Gardeners are here for you. Plant clinics in Burlington and Anacortes are staffed through October. Check the Master Gardener Plant Clinic Hours. Throughout the year you can submit a plant problem or question. Or leave a phone message at 360-395-2368, or send an email to askamastergardener@skagitmg.org

RESOURCES AND REFERENCES :

Pacific Northwest Gardener’s Handbook: Growing for the Future. Washington State University Extension, Pullman, Washington. (Rev. 2025)

ABOUT THE AUTHOR:
Diana Wisen has been a Skagit County WSU Extension Master Gardener since 1991 and is the coordinator of the Hardy Fuchsia Garden at the Discovery Garden on SR 536 in Mount Vernon. Diana is a member of the master gardener training team each year, teaching on a variety of topics including tool maintenance, managing slugs and snails, and weed identification.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Post: August 15, 2025

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Let’s Talk About IPM – Integrated Pest Management

Thoughtful pest management methods protect pollinators and your plants

By Deborah Smeltzer, Skagit County WSU Extension Master Gardener

Deborah Smeltzer

You are not sure what is wrong with your plant. You are fairly certain it does not look normal and is not growing as it should. You ask, “Am I watering it enough? Am I watering it too much? Does it have a disease? Is some kind of pest causing damage? If so, what should I do? Is there a pesticide that would solve this problem?”

Many of us who garden today would like to create a climate-resilient garden by optimizing soil health, managing our plant selection, determining the best methods for how and when we water, and knowing when it is appropriate and safe to use chemicals. One of the first steps to enhancing sustainability in our gardens is to understand the principles and strategies of Integrated Pest Management, or IPM.

Definition of IPM
“Integrated pest management is an environmentally friendly and common-sense approach to managing insects, diseases, weeds, and other pests of landscapes and gardens by using all the various tools available to gardeners, starting with their skills of observation.”¹

IPM helps gardeners to undertake a variety of control methods when needed. These include prevention and cultural, mechanical, biological, and chemical methods. Thoughtful choice of the tools in this toolbox helps us to optimize the health of the plant and the sustainability of our garden. Think about pest control as addressing not just herbivore pests such as insects, slugs, and vertebrates, but also weeds and diseases. Weeds outcompete plants for nutrients. Preventing the presence of weeds or removing them when they are small is a great example of IPM. Incorporating IPM into our garden management is a way to apply a more holistic approach to solving our plant problems.

When we train new master gardener volunteers, we talk about IPM as a common sense approach that uses science, plant health, our skills, patience, and tolerance to manage plant problems.² We know that if we can better understand the biology of the pest, we can make better decisions about how and when to manage our activities to address pest problems.

Please remember that happy, healthy plants are much less likely to need pest control!

Cabbage moths are a pest which lays eggs on all cruciferous vegetables (broccoli, Brussels sprouts, cabbage, cauliflower); the larva/worm chews the plants. © Photographer: Russ Ottens | Bugwood.org

Floating row covers such as Reemay®, controls cabbage moths by physically preventing them from reaching the plants to lay eggs. © Skagit County WSU Extension Master Gardeners

How IPM Contributes to Plant Health Care

IPM is one component of a holistic system of plant health care that allows us to focus on healthy landscapes by being observant about our plants’ cultural needs, the likely pest problems they might encounter, and environmental problems that might be common in their microenvironment. By frequently monitoring our garden, we can be in a better position to observe those conditions that allow our plants to thrive or that might cause problems. Monitoring allows us to be on the lookout for emerging problems before they become too severe to be solved.

Gardeners who take the time and effort to understand the interplay between cultural practices, soil conditions, and growth requirements for specific plants will be in a better position to minimize the impact of adverse environmental conditions.

It is very important to know the garden’s ecosystem to connect the dots between cause and effect. Routine observations help to quickly address factors such as pests, disease, or weather-related damage that could affect our healthy plants. Also, we need to be sure to have a proper diagnosis of the plant problem BEFORE we decide on which IPM solution will be most effective. A successful outcome of our IPM approach will be the reduction of pest populations, not complete eradication.

One of the goals of IPM is to reduce pesticide usage in our landscapes. By looking at the whole picture of what is happening in our garden, we have the opportunity to reduce the use of pesticides by 50 to 90 percent and create a more sustainable environment.³ Many home gardeners use more chemicals than agricultural operations. By tolerating some damage, we can reduce the overuse of chemicals and ensure less toxicity to our environment.

IPM Strategies

Each form of control needs to be chosen at the proper time. This is another reason that monitoring is so important. There is no reason to undertake control if the pest has not yet emerged in the garden or is no longer present. The observant gardener will know when an insect pest’s eggs hatch relative to the timing of leaf emergence of that insect’s favorite host plant. Covering cruciferous crops with row covers after the cabbage moth has visited is too late to prevent damage. Many fungal diseases target blossoms or new growth and need to be addressed during a discrete seasonal window.

Collecting slugs off of plants and disposing of them is an example of IPM mechanical control. Using slug bait is an example of chemical control. More about managing slugs can be found at: skagitmg.org/managing_slugs_snails/ © Photographer: Christine Farrow

Disposing of tent caterpillar egg casings before they hatch rather than spraying is another example of a mechanical or physical IPM method that protects the surrounding ecosystem. Learn more at skagitmg.org/tent-caterpillars/ © Photographer: Virgene Link-New

Mechanical and Physical Control can be used to make the environment unfavorable for the pest to exist. This might include devices that block pest access to plants, such as physical barriers or tools for pest removal. Examples include:

• Fly swatter
• Netting – Reemay® for insect exclusion or bird netting
• Weeding (before seedheads appear!)
• Traps – for insects or rodents
• Disposal of slugs and snails early in the season
• Installation of wire mesh at the bottom of raised beds to deter voles

Cultural Control means the manipulation of the plant or the environment to change the conditions and reduce the likelihood of pest problems. It requires knowledge of the biology and behavior of both the plant and the pest. This approach includes the philosophy of “Right Plant, Right Place,” which refers to selecting plants appropriate for the area where they are planted to increase growing success and reduce plant stress. Plants that are stressed are more susceptible to diseases and invite pests. Some examples of cultural control are:

• Selecting plants with resistance to common pests
• Proper planting techniques and dates
• Crop rotation
• Pruning
• Site condition management, such as the use of water and mulch

This Month in Your Garden

– Early to Mid-August –

• Fertilize roses once more before before allowing them to go dormant.
• Harvest garlic when the lower 1/3 of leaves turn brown.

– August – September –

• Prune bamboo culms to thin your bamboo. Prune older (without sheaths), leaning, or damaged culms and cut them close to the ground.  Prune any culms encroaching into an undesired area, and don’t forget root pruning to contain your grove.
• Deadhead perennials that self-seed, such as calla lilies, Shasta daisy, and crocosmia to prevent propagation.
• Harvest onions and shallots when the necks become soft and the tops fall over.

Biological Control is when other living organisms are used to control pest organisms. A few examples are:

• Release of lady beetles to control aphids
• Using herbivores like goats to control weeds 

Chemical Control is when pesticides are used to control pests and should be the control method chosen only when other options are not available. Pesticides are regulated and have detailed labels and instructions that need to be followed. Be sure to choose a chemical that is the least hazardous to the environment. Several key factors are important before choosing a chemical control. In most cases, the pest needs to be active. In addition, pollinators that are vital to plant health and food production need to be protected, as well as their water sources. Many insecticides will also harm beneficial insects, so it is key to READ THE LABEL and also be willing to tolerate some damage.

In summary, IPM is a science-based approach to gardening that enhances the sustainability of our gardens. “The approach is straightforward: identify the pest, assess its severity, determine its life stage, consider the site’s conditions, weigh risks and benefits, select a management strategy, and take action (or choose not to) with safety and environmental responsibility in mind.”⁵ Frequent observation and monitoring, along with concise diagnosis of plant problems and selecting appropriate preventive and control measures, can help us achieve a healthy, happy planet.

Know & Grow: The Allure of Dahlias
with Steve Lloyd

Free, no registration required
Come hear local expert, Steve Lloyd, the “Dahlia Doctor,” talk about mid- and late-season care, plus the winter care options for these stop-you-in-your-tracks plants.

Tuesday, August 19, 2025
1 pm – 2:30 pm
NWREC Sakuma Auditorium
16650 State Highway 536, Mount Vernon

New Certificate Programs in Skagit County

Washington Gardener Certificate Program is designed to provide comprehensive research-based horticulture and environmental stewardship education. This option is ideal for individuals seeking to enhance their gardening skills without the commitment of volunteering. This self-paced, online-only course provides a certificate upon successful completion. Registration deadline: Sept. 30, 2025. For more information, go to https://skagitmg.org/home/green-school/

Climate Stewards Certificate Program is a collaborative, multi-institutional group working across disciplines to promote climate awareness, education, and action. Registration deadline: Sept. 16, 2025. Learn more about the program: https://extension.wsu.edu/skagit/skagit-climate-stewards/

REFERENCES AND RESOURCES:

1. Pacific Northwest Gardener’s Handbook. 2025. WSU Extension, Master Gardener Program. Chapter 21 [quotation is on page 21-3] Available at:
2. Pautzke, K. 2025. Skagit County WSU Extension Master Gardener Training 2025, IPM slides.
3. Holmes, J.J. and Davidson,J.A. 1984. Integrated Pest Management for Arborists: Implementation of a Pilot Program. Journal of Arboriculture 10:65-70.
4. National Pesticide Information Center (NPIC)
5. Collman, S. 2025. Integrated Pest Management (IPM) is a Decision You Make. Summary of 2025 Advanced Education Conference lecture hosted by Master Gardener Foundation of Washington State.

ABOUT THE AUTHOR:

Deborah Smeltzer is a Skagit County WSU Extension Master Gardener (EMG), Class of 2012. She currently serves on the Skagit County Master Gardener Foundation board and as chair of the Skagit County WSU EMG Program Training Team. In 2020, Deborah was named Washington State Master Gardener of the Year by the Master Gardener Foundation of Washington State.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Posted August 1, 2025

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The Vital Role of Trees in Our Ecosystem and Well-Being

By Kathy Wolfe, Skagit County WSU Extension Master Gardener

Kathy Wolfe

Imagine for a moment that you are in a woodland. Every shade of green, from the deepest emerald to the lightest celadon, is represented in the surrounding landscape. The air is filled with scents from tree oils and the earth: cedary bark, musty decaying wood, leafy freshness. Overhead boughs scratch and moan as the wind blows through the canopy. A squirrel scampers across the forest floor, and birds sing overhead. Your step slows. Your breath softens. This is the feeling the Japanese describe as “forest bathing.” Being in the company of trees is said to reduce stress, boost the immune system, and improve your overall feeling of well-being. This is but one benefit of having trees in our lives.

Humans have revered trees in religions and cultures throughout time. European Druids worshiped oak trees, believing them to be a connection between the earth and spiritual worlds. The Native American cultures often viewed trees as sacred and integral in their spiritual and cultural lives and as sentient community members that lived among them. African Baobabs are known as the “Tree of Life” and symbolize resilience and humility. Many Asian cultures have sacred trees, including the Bodhi tree, where Buddha is said to have achieved enlightenment, the Kalpavriksha in Hindu culture, which is believed to grant wishes, and the shinboku, which are often planted near shrines in Japan.

Used with permission © Crowell Photography

Used with permission © Crowell Photography

Science has proven the functional benefits of trees as well.
Here are some examples:

Removing pollutants from the atmosphere.
Tree leaves filter dangerous particulate matter that comes from burning fossil fuels by intercepting the particles on plant surfaces. Gaseous pollutants are absorbed through the leaf stomata, which are tiny pores on leaf surfaces. Gases like ozone, carbon monoxide, nitrogen dioxide, and sulfur dioxide can be diffused into the intercellular spaces within the leaf. Some can also be metabolized or broken down by plant enzymes.
Mitigating climate change by storing carbon.
Trees absorb carbon dioxide from the air through photosynthesis and store it in their wood during the lifetime of the tree, helping slow gas build up in our atmosphere. Using sunlight, trees convert carbon dioxide and water into sugars for energy and release oxygen as a byproduct. Older, larger trees store more carbon than young trees, making it important to conserve and protect old-growth forests as well as plant new trees.
Managing stormwater runoff and erosion.
Flash flooding can cause immeasurable damage to the earth. Trees can reduce storm runoff and capture it in underground water-holding aquifers, which, in turn, counter droughts. The water seeps through the trees’ natural filters over time, so the water supply is steadier and the rivers do not carry away the rainwater. Tree roots bind the soil to the earth and decrease the speed and intensity of the runoff. Leaves break the force of the wind and rain beating down from above. Trees filter sewage and farm chemicals, animal waste, and roadside spills, making it easier and cheaper to treat water before it enters your tap.

Interested in Becoming a Master Gardener?
Application Deadline: Friday, August 15, 2025

Check out the new program for master gardener learning through WSU’s Washington Green School. You’ll join a community of gardeners dedicated to protecting Washington’s environment and learn skills to garden responsibly in our changing climate. Learn practical techniques, connect with experts, and discover how your actions contribute to a healthier future for all.

For more information, go to Washington Green School. 

Apply to the Skagit County WSU Extension Master Gardener Program.

Reducing wind damage and saving energy.
Trees located on the windward side of a property reduce the drying effects on the soil and vegetation in the summer or during a drought. In winter, these windbreaks can reduce snow drifts and even lower heating bills in the depths of a cold, stormy spell.
Providing habitat for a diversity of life.
Trees are used for food, shelter, and reproduction sites for various species. Many animals also nest and rest in their branches, hunt and capture prey from their hidden perches, and provide them with shade and shelter from the weather. Once a tree matures, its fruits become a food source. And when they are dead and dying, these snags are used by birds and insects for nesting hollows and foraging stations. Decaying trees become softer as they age, as fungi, bacteria, and wood-boring insects eat and break down the wood. The softwood tissue offers an ideal place for many young trees to begin their initial growth and development. The deadwood from these nurse logs also serves as ground cover that reduces soil erosion and prevents larger animals like deer from over-browsing plant seedlings. 
Shade and noise control.
Tree shade acts like a natural air conditioner that can keep down energy costs as well as making us more comfortable. Trees are planted to muffle urban noise from freeways and airports, and are almost as effective as concrete walls for this purpose. And much more pleasant to look at!

These are but a few examples of the majesty of trees in our environment. If you think that humans could live without them, think again. Now go out and give your favorite tree a big hug!

Know & Grow: Dahlias

Free, no registration required
Tuesday, August 19, 2025
1 pm – 2:30 pm
Sakuma Auditorium at NWREC
16650 State Highway 536, Mount Vernon

Visit the Skagit County Master Gardener Booth at the Fair

Exhibits Building “D”
Thurs. – Sun., Aug. 7 – 10, 2025
– Mystery Boxes where kids of all ages can explore nature by touch 
– Plants for firewise gardening
– Learn about building healthy soils for healthy plants

REFERENCES AND RESOURCES:

Bradford, N. (2016) The Many Benefits of Trees. National Environmental Education Foundation  (NEEF)

6 Ways Trees Benefit All of Us. (2020) The Nature Conservancy.

How Trees Make a Difference. National Wildlife Federation.

9 Reasons to Plant a Tree. (2018) Arbor Day Foundation.

Nix, S. (Rev. 2021) Reasons Living Trees are Valuable, Treehugger.

ABOUT THE AUTHOR:

Kathy Wolfe has been a Skagit County WSU Extension Master Gardener since 2002. She is co-manager of the vegetable garden at the Discovery Garden on SR 536 west of Mount Vernon.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Attracting Pollinators to the Home Garden

Making the right plant selections will help draw pollinators to the home garden

Posted July 18, 2025

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By Kari Ranten, Skagit County WSU Extension Master Gardener

Kari Ranten

Pollinators are the heroes in our landscape and food chain. The small but mighty bees, hummingbirds, butterflies, and other birds and beneficial insects are key to crop production and creating a diverse environment. The home gardener often sets out to create a pollinator-friendly landscape and quickly discovers how enjoyable it is to watch these pollinators in the garden.

Proper plant selection and placement is key to luring vital pollinators to the home garden.

Scientific research emphasizes the importance of pollinators, crediting them with the reproduction of 90 percent of flowering plants and one-third of human food crops. “Each of us depends on these industrious pollinators in a practical way to provide us with the wide range of foods we eat. In addition, pollinators are part of the intricate web that supports the biological diversity in natural ecosystems that helps sustain our quality of life,” say the authors of Selecting Plants for Pollinators.

“Without bees, there would be no apples, pumpkins, strawberries or many other fruits and vegetables . . . Approximately one in three mouthfuls of food and drink require the presence of a pollinator.” – Xerces Society

Research shows that pollinator populations, including bees and butterflies, are declining in Washington state and the United States. “Unfortunately, the numbers of both native pollinators and domesticated bee populations are declining. They are threatened by habitat loss, disease, and the excessive and inappropriate use of pesticides.” ² In March of 2025 Washington State University staff published a study showing that butterfly numbers have decreased by more than 20 percent from 2000 to 2020, with some species declining by more than 90 percent.⁷

Selecting the right plants is foundational to drawing pollinators to your garden. The two Pollinator Gardens in the Skagit County WSU Extension Master Gardener Discovery Garden, west of Mount Vernon, provide examples of plants that attract pollinators throughout the seasons. Master Gardener Alix Foster oversees the Pollinator Gardens and several years ago wrote an article describing the basics about the pollination process and why pollinators are so important, along with what each gardener can do to support pollinators. Read the article here >

Spiraea japonica Golden Princess attracts pollinators in the Pollinator Garden in the Discovery Garden.
© Skagit County Master Gardeners

Jacob’s Ladder (Polemonium reptans) and foxglove attract various pollinators, especially bees. Other pollinators like butterflies, moths, and flies are also attracted to the flowers. © Skagit County Master Gardeners

Foster recently led a tour of one of the compact Pollinator Gardens to showcase the selection and placement of plants that maximize the number and variety of bugs and birds visiting the garden. Efforts are underway to add more native plants and enhance the number of plants that bloom in sequence over the months along with a variety of colors, shapes, and sizes to span the seasons. During daytime hours, 365 days a year, enjoy a self-guided tour of the Discovery Garden where signs list the plant names, what pollinators they draw, and the bloom time for the specimens on display. To see the complete list of plants in the Pollinator Gardens at the Discovery Garden, go to https://skagitmg.org/home/discovery-garden/pollinator-garden/.

Fortunately, there is an abundance of options for pollinator-friendly plants. The Pollinator Partnership, a global non-profit dedicated to the protection and promotion of pollinators and their ecosystems, offers a tool on their website to generate a list based on zip code at https://www.pollinator.org/find-your-roots-tool. A search using Mount Vernon, WA 98273, yields a list of 1,172 perennial flowers, shrubs, and trees to consider for a pollinator landscape.

Several fundamentals apply when choosing plants to draw pollinators:

Use native plants: Natives, including wildflowers, shrubs, and trees, are naturally adapted to the region’s climate and soil. Research by Gordon Frankies ³ shows native plants are four times more likely than non-native plants to attract bees and significantly increase the abundance of butterflies and moths. The Salal Native Plant Garden, adjacent to the Discovery Garden, introduces home gardeners to many varieties native to northwest Washington. According to the Pollinator Partnership, “Non-native plants such as cultivar and hybrid plant species are, in most cases, not good for pollinators as they can result in double flowers, changes in flower color, and sterile flowers with no pollen.”

Select plants that bloom across the seasons: Flowering plants, including annuals and perennials, serve as a draw for pollinators. When shopping for plants, nursery tags often list the pollinators that are attracted to the specific plant. As an example, a tag on Monarda fistulosa, a perennial commonly called bee balm, lists that the deep pink blooms attract bees, hummingbirds, and butterflies.

Pollinators love flowers – keep blooms going throughout the seasons: Pollinators are drawn by a variety of plant qualities, colorful blooms, and the availability of pollen and/or nectar.

Interested in Becoming a Master Gardener?

Application period is now open through August 15, 2025.

WSU has recently launched a new training platform called Washington Green School, designed to provide comprehensive research-based horticulture and environmental stewardship education. The Washington Green School offers two distinct tracks:

• Washington Gardener Certificate Track
  This option is ideal for individuals seeking to enhance their gardening skills without the commitment of volunteering. This self-paced, online-only course provides a certificate upon successful completion.
• Extension Master Gardener Volunteer Track
  This track is for those interested in becoming certified WSU Extension Master Gardener volunteers and includes the Green School online coursework, in-person, local volunteer training, and a commitment to volunteer service hours.

For more information, go to https://skagitmg.org/home/green-school/

To apply for the Skagit County WSU Extension Master Gardener Program, go to https://extension.wsu.edu/skagit/mg/apply/

In the search for food resources, each type of pollinator has preferences for the color, nectar, odor, pollen, and flower shape. The Pollinator Partnership has compiled the Pollinator Syndromes chart below describing characteristics which draw eight different pollinator groups. For example, butterflies prefer flowers shaped like a narrow tube with a spur and a wide landing pad, often in bright red and purple colors. Bats pollinate plants which emit strong musty scents and open at night.

In addition to referring to the plant lists for the two local Pollinator Gardens, consider regular visits to the Discovery Garden or local nurseries to check what is blooming each month, or seek out another pollinator garden, such as Pollinator Pathway Northwest at 21 Acres in Woodinville (https://21acres.org/).

Plant several similar plants in close proximity: Create several extensive, round plantings of each plant to minimize the distance pollinators need to travel to obtain their nutrition and transport pollen. Additionally, experts recommend planting at least three different pollinator plants within each of the three blooming seasons: spring, summer, and fall ³ for maximum benefit.

Consider a bee lawn: Adding flowers in with turfgrass can provide a draw for pollinators seeking nectar and/or pollen. The bee lawn is available for human recreation and as an attraction for dozens of species of native bees ^4.

Use care with chemicals: For details about chemical use to protect pollinators, see Washington State University Extension bulletin “Pollination and Pollinator Protection” in the references below.

In addition to flowers and plants, home gardeners should be aware of the basic needs of pollinators:

• Appropriate nesting areas Off-season hibernation sites
• Good sun exposure
• Adequate source(s) of water
• And lastly, allow leaves to gather [and self-mulch] on the ground as a haven for insects, birds, and others through winter.

REFERENCES AND RESOURCES:

1. Lawrence, T. (2015) WSU Extension bulletin FS174E. Pollination and Pollinator Protection (Home Garden Series). 
2. Ley, E., Buchmann, S., and Holmes, K. (2025) Selecting Plants for Pollinators Including the states of: Oregon and Washington a Regional Guide for Farmers, Land Managers, and Gardeners in the Pacific Lowland Mixed Forest Province. The Pollinator Partnership™/North American Pollinator Protection Campaign.
3. Mader, E., Shepherd, Matthew, Vaughan, M., Hoffman, S., LeBuhn, G. (2011) Xerces Society Guide: Attracting Native Pollinators. Storey Publishing. North Adams, MA.
4. Moncada, K., Reiter, M., and Wolfin, J. (2023) Planting and maintaining a bee lawn. University of Minnesota Extension.
5. Pollinator Partnership. (2025)
6. Pollinator Threats. (2025) Pollinator Partnership.
7. U.S. Butterfly Populations are Severely Declining. (2025) Washington State University Office of Research. (2025)
8. Wollaeger, H., Getter, K. and Behe, B. (2015). Consumer Preferences for Traditional, Neonicotinoid-free, Bee-friendly, or Biological Control Pest Management Practices on Floriculture Crops. Michigan State University Department of Horticulture. HortScience 50(5):721-732.

ABOUT THE AUTHOR:

Kari Ranten is a retired journalist and health care communicator who became a certified Skagit County WSU Extension Master Gardener in 2024. 

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Pets and Home Gardens

Protecting your pets from the plants and your plants from your pets!

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By Deborah Leitner, Skagit County WSU Extension Master Gardener

Deborah Leitner

Several years ago, when we adopted our beloved black lab Shadow from the Seattle Humane Society, I had visions of my new best friend spending hours with me in the garden, frolicking by my side, as I weeded, puttered, planted, pondered, and pruned my way through my fenced-in urban backyard oasis. Shortly after we got him home, it became clear that Shadow had a different plan.

Shadow’s propensity for joyful exuberance posed specific gardening challenges, as he loved to dig, eat strawberries and vegetables, and generally disturb any carefully laid out plans. Some plants were lost, but I found a new focus in creating an environment where he could frolic and play, and we could enjoy him while not stressing too much if any plant or shrub got injured in the process. Both pets and gardening require planning, patience, and a healthy dose of reality.

What to Avoid
The ASPCA (American Society for the Prevention of Cruelty to Animals) offers a comprehensive list of toxic plants for dogs, cats, and horses on their website. (See reference below.) This website also provides a complete list of safe and non-toxic plants for pets.

Examples of toxic plants that are common in Pacific Northwest backyards include:

Daffodils: The flowers, leaves, and bulbs can cause abdominal pain, vomiting, and diarrhea. In severe cases, cardiac arrhythmias and respiratory problems may occur.

Lily of the Valley: Dogs who eat lily of the valley may experience cardiac arrhythmias, decreased heart rates, and seizures.

Tulips and hyacinths: The bulbs are toxic. Mild cases show drooling and some vomiting. If dogs eat too many, they may show an increase in heart rate.

Azaleas: These can be fatal if your dog even chews on leaves.

The above list is not meant to be all-inclusive but rather a sampling of the most commonly encountered toxic plants in urban backyards. For more detailed lists, check out the WSU and ASPCA references below.

Also, many houseplants are toxic to both cats and dogs. Be sure to keep your indoor plants well out of reach of pets. A few of the most toxic plants include aloe, philodendron, pothos, jade plant, and asparagus fern. If you need help identifying your houseplants, the master gardeners at the WSU Extension Plant Clinics in Burlington or Anacortes or the Farmer’s Market booths in Mount Vernon or Sedro Wooley are excellent resources for identification of plants.

According to the ASPCA, it is a myth that dogs and cats instinctively avoid toxic plants. If you see your dog or cat eating a plant and are unsure if it is harmful, it is best to contact your vet as soon as possible. The ASPCA Animal Poison Control Center is also available 24 hours a day, 365 days a year, at (888) 426-4435 to answer any questions in an emergency.

What to Plant
There are many plants that both do well in the Pacific Northwest and are safe for dogs. The following list highlights some of the safe plants that are commonly found in PNW backyards:

Shrubs: Abelia is a hardy shrub that can tolerate many challenges, including being sprayed with dog urine. Green Mountain boxwoods, cypresses, and Rocky Mountain Juniper are good hedge options. Mature shrubs are more resistant to dog damage.

Trees: Camellias, magnolias, and Japanese maples are all good choices

Perennials: False goat’s beard (Astilbe,) ornamental grasses, red hot pokers (Kniphophia,) goat’s beard, echinacea, and rudbeckia all seem to tolerate the paw traffic.

Annuals: Sunflowers, fuchsia, pansy, and petunia are all safe for dogs. 

Herbs: Organically grown edible herbs are a good option. 

Native plants: Salal, evergreen huckleberry, Oregon grape, and western sword ferns are all hardy natives that are safe for dogs. 

Other plants: Japanese aralia, hardy geranium, coreopsis, and nasturtiums are all dog-friendly plants

If you have a fence, try leaving a few feet between the fence and your plants. Dogs love running the fence line, chasing squirrels, saying hi to neighbors, and protecting their humans. You are saving your plants from being trampled by giving them space to do so.

Perennials such as red hot pokers (Kniphophia), goat’s beard, echinacea, and rudbeckia all seem to tolerate paw traffic.  Photo © Adobe Stock

If your pets have room to roam outside, it is critically important to identify the plants growing where they roam. Poison-hemlock is highly toxic to humans and animals and should be removed following Washington State Noxious Weed Control guidelines. Photo © Adobe Stock

Fertilizing and Mulching
Commercially prepared, organic compost on garden beds is a safe choice for dog owners. A risk is involved if using homemade compost, as mold and fungi may be present in the decomposing material containing neurotoxins. Arborist wood chips are an excellent option for mulching, but some dogs (like mine) love to eat the chips, posing other risks.

Two mulches to avoid are cocoa mulch and pine needle mulch. Cocoa mulch contains theobromine, a toxin that is dangerous to dogs. Pine needle mulch can damage your pet’s stomach lining.

If you fertilize your lawn, be sure to read the label carefully. Many products say they are safe for use around pets, but they still recommend that you keep pets off the recently fertilized grass for up to 48 hours. Consider using a mulching lawn mower, leaving the cut grass in a place where it will break down and add nitrogen back to the lawn. Another option is to let your lawn go dormant in the summer, knowing it will return to life in the fall.

Got Slugs?
If you garden in the PNW, you are likely familiar with slugs. Our most famous native slug, the banana slug, is mainly seen in the forest, eating away at decaying matter. Slugs, specifically native slugs, have their place in the greater scheme of things; they are vital to the decomposition of organic matter and provide food for birds, snakes, frogs, and other animals. However, most slugs the home gardener encounters are not native, having been introduced from Europe. Once introduced, they made themselves right at home and drive the home gardener crazy.

Commercial slug products containing metaldehyde are highly toxic to pets, birds, wildlife, and humans, and should be used with a tamper-proof bait station, if used at all. Poisoning occurs even if a small amount is ingested. Products containing iron phosphate are considered safer for people and pets, but should be used cautiously, as poisoning can still occur if your pet ingests large amounts. If you choose to use the products containing iron phosphate, read the instructions carefully, and consider putting a barricade such as a small fence or wire basket around the plant in question to prevent your dog or cat from getting near the product.

Some gardeners use broken shells, lava rock, or other rough materials to deter slugs from the area without using chemicals. Placing copper bands around plants or planting lavender, mint, or rosemary may discourage slugs and snails from entering the garden.

A safer alternative is to trap the slugs using bait. Bury a container such as a margarine tub containing yeast mixed in water (beer works well for this method), so the slug will fall into the trap and drown. You will need to monitor the trap and replace the bait regularly. Baited traps don’t discriminate by species, however. Other small wildlife can meet their end by falling into the trap. It’s a good idea to remove the trap during the day so that Fido isn’t tempted to indulge, and then set the trap out again in the evening.

Many gardeners prefer controlling slugs manually. It is time-consuming, but tried and true. Fill a jar with soapy or salty water, pick the slugs from the plants, deposit them in the jar, seal them, and wait a few days. Then flush the contents down the toilet. Over time, your slug population will substantially diminish, and your pets and other wildlife will be safe from chemical (and alcohol) poisoning. Learn more about managing slugs. 

Overall, the toxicity of slug bait is a significant concern for pet owners. Prompt intervention is crucial if poisoning is suspected, and preventive measures can help ensure the safety of your pet.

Shadow living the good life. Photo © Deborah Leitner

Shadow never lost his youthful exuberance and propensity for mischief in the garden. He lived a joyful life, but sadly, at age 13, it was time to say goodbye. It took a while to be ready for a new canine companion, but Shadow’s successor, Teddy, was found at the Skagit Valley Humane Society. Or you might say Teddy found us because we certainly didn’t expect to come home with a 10-year-old black lab mix. But discovering the joy of living with a mature senior dog, Teddy is a good match. Teddy is not interested in gardening but loves being a backyard companion.

Know & Grow
The Science Behind Companion Planting
Tuesday, May 20, 2025
1 pm – 2:30 pm
NWREC Sakuma Auditorium
16650 State Highway 536, Mount Vernon

Based on research by horticultural scientists such as Dr. Linda Chalker-Scott and Dr Jeff Gillman, you will learn natural ways to prevent or lessen pest and disease problems in your garden. Use plant combinations, polyculture, and other science-based practices for a healthier garden. Master Gardener Rae Barto will share these findings and advice.

Mark Your Calendar:
Annual Three Garden Open House
Saturday, June 28, 2025
10 am – 2 pm
Discovery Garden
16602 State Route 536 (Memorial Highway)
Mount Vernon, WA 98273
Fun Activities for Kids  ~  Plant Sale
Water Conservation Experts  ~  Noxious Weed Information
30+ Garden Rooms  ~  Plant Clinic and Gardening Help
Native Plants  ~  Pollinators
Talk to Fruit Tree Experts

Interested in becoming a Master Gardener?

WSU is introducing a new program called Washington Green School which will include WSU Extension Master Gardener training. Beginning this fall, Green School will offer two distinct tracks in its online course: one for individuals looking to enhance their gardening skills through research-based horticultural and environmental stewardship, the Washington Gardener course, and another for those who wish to take it further by becoming a WSU Extension Master Gardener Program volunteer.

Learn more about Washington Green School training.

Applications to become a Skagit County WSU Extension Master Gardener are due by August 15, 2025 to be in the Class of 2026. Apply to be a WSU Extension Master Gardener.

REFERENCES AND RESOURCES:

Chaulker-Scott, L. (2007) Wood chip mulch: Landscape boon or bane? Retrieved at Hedgerow: Mulches

Animal Poison Control. American Society for the Prevention of Cruelty to Animals. 

Toxic and Non-Toxic Plant List – Dogs. American Society for the Prevention of Cruelty to Animals. 

Toxic and Non-Toxic Plant List – Cats. American Society for the Prevention of Cruelty to Animals. 

Plants Toxic to Dogs. Cornell University College of Veterinary Medicine.

Plant Toxicity and Pets. Texas A & M University Extension.

ABOUT THE AUTHOR:
Deborah Leitner is a WSU Extension Skagit County Master Gardener class of 2007. Along with caring for the Discovery Garden, she can often be found helping answer questions at the Plant Clinic in Burlington.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the Extension website.

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Hooray for Hydrangeas

Gardeners are quick to show you their favorite hydrangeas, but many question how and when to prune them

By Diana Wisen and Janine Wentworth, Skagit County WSU Extension Master Gardeners

Authors Diana Wisen and Janine Wentworth

Hydrangeas, with their stunning blooms, have been captivating flower enthusiasts for centuries. The ability of some varieties to change color based on soil pH adds an element of magic. They can be big and bold or lacey and layered. All varieties grow well in sunny locations, perhaps with some afternoon shade-all varieties like acidic, moist, humus-rich soil that drains well. While hydrangeas can tolerate neglect, they do better if watered in the high heat of summer. Additionally, a layer of arborist chip mulch spread well beyond the outer drip line of the branches will help retain moisture.

How to Prune Hydrangeas
Hydrangeas do well in the Pacific Northwest, thriving in our climate and native soil. They do not need to be pruned to do well, but many homeowners like a more tidy look, which requires pruning. Others prune to keep their hydrangea varieties smaller than their normal growth habit. Sometimes, severe winter cold causes damage to the current season’s buds, and you may want to remove the damage. For most varieties, the best time to do all of this is in the spring before they leaf out.

The first step to pruning any hydrangea is to know what kind it is. Different kinds are pruned differently, and if you don’t know what kind you are pruning, you may be cutting off all the potential flowers by pruning at the wrong time. Save the plant tag and learn to recognize the variety you have. That is the key to a successful start.

Hydrangeas start blooming in mid-summer and bloom for a long time. There is no need to prune in winter. In fact, leaving on the dead flower heads can protect emerging buds from freezing. Hydrangeas are deciduous, but their leaves hang on well into fall. Leave them where they fall on the soil.

Learning to recognize dead wood can be tricky with hydrangeas. Older stems often look dead, but they are not. Dead stems are usually three or more years old. On some specimens, the dead stems may even be ten years old. To identify dead wood, look for stems with no buds or leaves. These can be cut back to the base of the plant. If you are unsure, start cutting from the tip of the branch and look for a greenish interior on the stem, or scrape the bark with your fingernail. If it’s brown, crisp, and very dry, it’s dead. You can cut the dead wood on any hydrangea back to the ground. You can also prune out wayward-looking stems or those that are too crowded.

The most common kind of hydrangea is H. macrophylla or bigleaf hydrangea, of which there are two types: mophead and lacecap. © Crowell Photography

A lacecap hydrangea has flatter inflorescences or flower clusters with small sterile flowers around the edges and tiny fertile flowers in the center, giving it a delicate lacy appearance© Pexels.com | Dayong Tein

Now for the Differences
The most common kind of hydrangea is H. macrophylla, or bigleaf hydrangea, of which there are two types: mophead and lacecap. All bigleaf hydrangeas bloom on wood formed the previous year and on buds set last summer. When all danger of a hard frost is past in late spring, remove the dead flower heads by cutting back to a pair of healthy fat buds, which will be your flowers. Slender buds are the leaves. Even if you choose not to remove or prune the dead flower heads from last season, H. macrophylla will still bloom just fine.

The standard bigleaf hydrangea wants to be big and tall genetically. It is difficult to reduce the size of a mature hydrangea. If pruned hard, it will grow back to its original height but have weak stems and no flowers that year. It is better to cut select older stems to the ground to reduce the size of the plant. Doing this will shorten your plant and will necessarily sacrifice flowers. Some newer cultivars have been bred to stay small. These may be a better choice for your landscape than constantly pruning to reduce the size of a large hydrangea.

A popular mophead type is ‘Nikko Blue’. The flowers are big, rounded heads consisting of all sterile flowers. If the blossoms begin to turn pink and you prefer blue, make the soil more acidic by adding aluminum sulfate to the soil in the early spring. It may take more than one year and additional servings of aluminum sulfate to achieve blue blossoms. Note: Concrete sidewalks or foundations can leach lime into the soil resulting in pink hydrangea blossoms. However, some hydrangea varieties are naturally pink and will not turn blue in acid soils.

A popular lacecap hydrangea is ‘Mariesii’, with flatter inflorescences, or flower clusters, with small sterile flowers around the edges and tiny fertile flowers in the center, giving it a delicate lacy appearance. Lacecaps do not typically grow as tall as their mophead cousins.

Panicle hydrangea flowers are large, cone-shaped, up to 12 inches, blooming on sturdy stems, sometimes up to 10 feet tall. Panicle hydrangeas are best pruned in early spring to promote new flowering wood. © Ginny Bode, Photographer

Smooth hydrangeas (H. arborescens) like this cultivar ‘Annabelle’ have large snowball-like clusters and bloom on new growth of the current season so it can be pruned to the ground in early spring, leaving 2-4 inches. © Crowell Photography

Another popular hydrangea is H. paniculata. ‘Limelight’ and Grandiflora ‘PeeGee’ are popular panicle cultivars with many more on the market. Panicle hydrangea flowers are large, cone-shaped, up to 12 inches in length, and bloom on sturdy stems, sometimes to 10 feet tall. Flower color varies from creamy white to pale green, transitioning to pink hues as they mature later in the summer.

Panicle hydrangeas bloom on new wood, meaning the flower buds form on stems growing this season. Thus, you should prune all the previous season’s stems to two or three pairs of buds in the spring, which will bloom in the coming summer, giving you a low structure. You can also do selective pruning and cut some older stems way back while leaving some a little longer. If you don’t prune it all, the flowers will be so high up that you will not be able to enjoy them after a few years. Panicle hydrangeas are best pruned in early spring to promote new flowering wood.

Another kind of hydrangea is H. arborescens, or smooth hydrangea. An old and still popular cultivar is ‘Annabelle’. It has large snowball-like clusters of white flowers, which are white regardless of soil acidity. The flowers may fade to a soft pink near the end of the season.

Smooth hydrangeas flower on new growth of the current season, so stems can be pruned to 2-4 inches from the ground in early spring. Most have a rounded growth habit to 5 feet in height and width. There are newer cultivars on the market that are bred to stay smaller.

A hydrangea gaining popularity in the Pacific Northwest is H. quercifolia, commonly known as oakleaf hydrangea. Though native to the Southeastern United States, oakleaf hydrangeas do exceptionally well in the PNW and are known for spectacular fall color. The flowers and the leaves turn rich shades of red, orange, and purple in the fall and can last several months for additional seasonal interest. Its leaves look like large oak leaves and stay on the plant well into fall.

Oakleaf hydrangeas are one of the easiest hydrangeas to care for. They do not need to be pruned except to keep them out of a walkway. Plant them where they can have plenty of space to look their magnificent best, because over-pruning makes for weak, floppy stems. Plant them in full sun for good color.

H. anomala petiolaris, commonly called climbing hydrangea or hydrangea vine, needs support such as a tree trunk or fence to cling to; otherwise, it will spread among neighboring plants and be challenging to care for. Be patient; climbing hydrangeas are slow to begin blooming, sometimes waiting 3 to 5 years to begin flowering. They need very little pruning, and once established, climbing hydrangeas bloom on new shoots. You can deadhead the spent flowers if you wish. However, this variety can grow to 50 feet tall or more, so plan accordingly. And be forewarned-deer love to eat this kind of hydrangea

There are other kinds of hydrangeas: H. serrata and H. aspera, commonly known as mountain hydrangeas, are native to Japan and Korea. These are not widely planted in the Pacific Northwest. Mountain hydrangeas bloom on the previous year’s wood.

New cultivars are constantly being developed. A little over 20 years ago, a remontant (reblooming in same season) hydrangea was discovered in Minnesota. Years of intensive breeding trials resulted in a new, reblooming bigleaf hydrangea cultivar branded Endless Summer^®. The world of hydrangeas changed dramatically with this cold hardy hydrangea that would reliably bloom on both old wood and new wood the same summer, offering an extended season of fresh blooms. Since then many cultivars of repeat blooming hydrangeas have been released. These reblooming hydrangeas should be pruned only after the first blooming period.

Hydrangeas are a beautiful, easy-care additions to your landscape, providing cut or dried flowers and color to the landscape throughout their long bloom season. The stunning varieties require minimal pruning if planted in the correct location for size and growth habits. Always read and save the plant tag. Study your plant and learn its growth habit by observation throughout the season. Using these basic tips, your hydrangeas should bloom successfully year after year.

Listed below you will find a number of excellent resources for learning more about hydrangeas, including a book by Dr. Michael Dirr who identified the first reblooming hydrangea and worked with it to develop the cultivars branded under the name Endless Summer^®.

Mark Your Calendar: Always the Saturday Before Mother’s Day

We’re growing 3,500 tomato plants, and over 3,000 flower and vegetable starts along with edible and ornamental perennials for you to bring home and plant your garden this season.

RESOURCES:
Crosbie, C. (2007) Easy Pruning: Simple Steps to Success. Royal Horticultural Society and DK Publishing

Turnball, C. (2021) Guide to Pruning. (3^rd Edition) Sasquatch Books

Kourik, R. (1987) Hands on Gardener – Pruning. Workman Publishing, New York, New York.

Joyce, D. (1999) Pruning & Training. Eyewitness Garden Handbooks. DK Publishing.

Bird, R. (2006) Pruning Trees, Shrubs, and Climbers. Anness Publishing.

Reich, L. (2010) The Pruning Book. The Taunton Press.

Dirr, M. (2024) “Hydrangeas for American Gardens.” Timber Press.

ABOUT THE AUTHOR:

Diana Wisen has been a Skagit County WSU Extension Master Gardener since 1991 and is the coordinator of the Hardy Fuchsia Garden at the Discovery Garden.

Janine Wentworth is a Skagit County WSU Extension Master Gardener, Class of 2018. She is the coordinator of the Front Door Garden, the most recent addition to the Discovery Garden on SR 536 west of Mount Vernon.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Warmer Summers Impact Local Rhododendrons

From sun scorch to lace bug, local gardeners protect their beloved rhododendrons with these conscientious tips.

By Sonja Nelson, Skagit County WSU Extension Master Gardener

Author Sonja Nelson

Rhododendrons in our gardens, along with the native state flower Rhododendron macrophyllum, the Western or Pacific rhododendron in our woodlands, are facing the vagaries of climate change here in the Pacific Northwest as well as worldwide. Gardeners in our moderate climate can no longer assume our benevolent climate will continue its unstinting support for the genus Rhododendron. According to the World Meteorological Organization, the average global temperature in 2024 was the warmest year on record at about 2.7° F or 1.55° C above preindustrial levels. Higher temperatures do not bode well for rhododendrons. They like moderation!

Rhododendrons have a long history in the Pacific Northwest. Native Americans used the flowers of rhododendrons in their dance rituals long before western plant hunter Archibald Menzies identified the R. macrophyllum. Menzies was the surgeon-botanist for Captain George Vancouver on board the British ship ‘Discovery’ in 1792. The R. macrophyllum, or Western rhododendron, was sent to King George III and introduced to the Kew Gardens in London. The discovery brought together the British and American plant people who eventually produced a creative milieus communities of rhododendron enthusiasts that made the rhododendron the “King of Shrubs” on both sides of the Atlantic.

References to the Western rhododendron (Rhododendron macrophyllum) date back to native Americans using rhododendron flowers in their dance rituals long before the late 1700s. © Photo: Sonja Nelson

One hundred years after Menzies documented finding the Western rhododendron, the state of Washington sought a representative flower to display in the 1893 Chicago World Fair exhibit. The Washington State Fair Commission asked the state’s women to decide. A letter-writing campaign began, pitting the native rhododendron against, among others, the clover. (The vote was Western rhododendron 7,704 and clover 5,729.) It was officially designated the Washington State flower in 1959.

However, between the time the Western rhododendron was presented at the Chicago World Fair, rhododendron species from Asia, particularly the Himalayas, had been discovered by dedicated British plant hunters and sent back to Britain to adorn gardens there with their vibrant colors and to hybridize. Many Asian species and hybrids were also brought to America, where nurseries introduced them to the Pacific Northwest. Gardeners welcomed them with enthusiasm and love. And the rhodies loved them back with their stunning performance!

Meanwhile, Washington state’s native Western rhododendron grew in its native woodlands as the quietly attractive relative of the more flamboyant Himalayan species. In the 1970s the Western rhododendrons regained popularity as gardening with native plants became popular with the backing of  WSU Extension and the Washington Native Plant Society. In 1979, the First World Climate Conference declared climate change a global issue, and rhododendron gardeners’ concern turned to the native Western rhododendron and its environment, along with concern for their rhododendron species and hybrids from afar. The natural environment of the Pacific Northwest, so well suited for much of the genus Rhododendron, was becoming jeopardized by temperature increases and other disturbances to its blissful climate.

The complexity of a warming climate makes it difficult to predict precisely how rhododendrons will be impacted by our specific climate and what to do if it does. For instance, if temperatures increased enough to leave visible sun spots on the leaves of rhododendrons, the rhododendrons could simply be moved to a site with partial shade. However, the effect of a warming climate on plants is not always straightforward.

One solution to protect rhododendron gardens from climate change damage is to find varieties-both species and hybrids-that are tolerant of temperature increase and ensuing weather extremes.

A member of the American Rhododendron Society, C.J. Patterson of Massachusetts, has focused his interest in rhododendrons on finding drought-tolerant rhododendrons for East Coast gardens. He writes that “rhododendrons, in general, are mostly very resistant to dry conditions once they are established,” citing R. carolinianum, R. maximum, and R. catawbiense as drought tolerant. He says one of the most drought-tolerant rhododendron hybrids is the hybrid ‘PJM’ (R. minus var. Carolinian Group x R. dauricum) and other hybrids of the same cross.

The director of the German Rhododendron Society, Hartwig Schepker, supports the idea that the genus Rhododendron is diverse enough to cope with the challenges posed by extreme climate conditions, saying we find them or create new hybrids that will be up to the job.

Another rhododendron expert is Glen Jamieson, the editor of the Journal American Rhododendron Society, who often writes about the impact of climate change on rhododendrons, which, he says, has been relatively minor annually. In coming publications, he plans to summarize the weather impacts on his garden in British Columbia over the past 40 years, where there have been extreme cold, heat, precipitation, and wind events-all of which can be attributed to a changing climate.

Since it is difficult, if not impossible, to predict precisely the effects of climate change on rhododendrons in the future, conscientious basic care is the best way to help them survive hard times in the future. Washington State University lists watering, fertilizing, and mulching as basic care.

Basic Care for Rhododendrons
Washington State University Extension recommends this regimen of basic care:

Watering

• Water rhododendrons at least once a week, or when the top inch of soil feels dry.
• Avoid waterlogged soil, which can damage rhododendrons.
• Water well in the fall to prepare for winter

Fertilizing

• Use a fertilizer made for acid-loving plants.
• Fertilize in the spring when buds swell and in the fall after flowering.
• Follow the product label recommendations.

Mulching

• Use coarse organic mulch, like wood chips, to cover the root zone.
• Keep mulch at least 4 inches deep, but don’t let it touch the base of the plant.
• Mulch helps conserve water, reduce weeds, and moderate soil temperatures

Other Tips

• Plant rhododendrons in well-drained acidic soil
• Avoid dense or compacted soil
• Provide shade or semi-shade
• Prune out dead flowers
• Avoid overhead watering
• Maintain good air circulation
• Prevent injury to reduce the chance of infection
• Clean up and destroy fallen leaves

A Unique Opportunity to Observe Local Climate Change Impact
The coordinators of the various gardens within the WSU Extension Master Gardener Discovery Garden west of Mount Vernon were questioned about possible damage in their gardens due to recent summers with high temperatures. Five coordinators reported no change, and four coordinators reported slight changes. Ironically, six coordinators reported damage from unusual cold spells. The Rhododendron Garden coordinator, however, reported extensive damage to a large planting of small-leaved rhododendrons due to warming temperatures.

Rhododendrons are divided into two natural divisions: the lepidotes and the elepidotes. Small-leaved rhododendrons belong to the lepidote division based on the tiny scales on the undersides of their leaves. Elepidotes do not have scales and tend to be large-leaved.

Sun scorch on the leaves of rhododendrons has long been an occasional problem for gardeners, but the warming caused by climate change has introduced a new, insidious avenue for damage–the rhododendron lace bug (Stephanitis rhododendri). Believed to have migrated from California, lace bugs have taken advantage of the longer growing season in the Pacific Northwest and can complete their life cycle, where, in 2023, in the Rhododendron Garden, it laid eggs and, as a result, destroyed a planting of rhododendrons.

Rhododendron lace bug (Stephanitis rhododendri Horvath) © Insect Images Photographers: Seastone, L. and B. Parks

Azalea lace bug (Stephanitis pyrioides) © Photo: Jim Baker, North Carolina State University, Bugwood.org

The lace bug affected rhododendrons with small leaves, mainly in the island meadow section of the Rhododendron Garden, namely hybrids ‘Ramapo,’ ‘Ginny Gee,’ and ‘Patty Bee.’

The rhododendron lace bug has one generation per year. It overwinters as eggs laid on the underside of leaves. Nymphs are about 1/8 inch long and are spiny. Adults are about 1/8 inch long and whitish tan with lacy-looking wings. Damage is usually apparent by early to mid-July. The lace bug sucks on the undersides of leaves and causes stippling on the upper surface of the leaves and tar-like deposits of excrement on the lower surface. Repeated infestations may result in yellowed, sickly plants. Spraying the undersides of the plants to remove the lace bugs was considered impossible because the leaves grow so densely and so close to the ground; thus the affected plants were removed. New planting will take place in 2025.

The related azalea lace bug (Stephanitis pyrioides) has four to five life cycles annually. It infects rhododendrons also but has not been found in the Rhododendron Garden section of the Discovery Garden. Both types of lace bug overwinter.

Lacewing insect © Insect Images: Photographer: Johnny N. Dell

The lace bug is not to be confused with lacewing insects (Chrysoperla species) which are native to the Pacific Northwest and important natural predators providing biological control of aphids.

Treatment for Lace Bug
For non-chemical treatment, Washington State University recommends hand removal of adults and nymphs regularly to limit the amount of visible damage. This can be done with a strong spray of water.

If you choose to use a chemical treatment, two recommended pesticides that are legal in Washington are:     

• Safer Brand BioNEEM Multi-Purpose Insecticide and Repellent Concentrate [Organic] Active ingredient: azadirachtin [EPA registration number: 70051-6-42697]
• Safer Brand Garden Defense Multi-Purpose Spray Concentrate [Organic]
  Active ingredient: clarified hydrophobic extract of neem oil [EPA registration number: 70051-2-42697]

The best time to treat is May and June. For more information, download the WSU fact sheet on rhododendrons and lace bugs

The Rhododendron Garden in the Discovery Garden allows the public to view plants as they grow in our specific climate. The damage to some of the small-leaved rhododendrons is sad to see, but it gives gardeners the knowledge to make necessary changes in their gardens to keep them beautiful.

Soon, spring will once again bring forth the eye-catching, luscious blooms on the rhododendron hybrids planted in our gardens and the quietly elegant blooms of our native Western rhododendron at the edges of our woodlands.

REFERENCES AND RESOURCES:
Dale-Crunk, B. (2024) Personal communication.

Global Temperature Data Indicator. NASA

Skagit Climate Science. Air Temperature and Precipitation 

Washington State University. (2024) Rhododendron: Rhododendron and Lace Bug fact sheet.

Pojar, J. and MacKinnon, A. (1994) Plants of the Pacific Northwest, B.C. Ministry of Forests and Lone Pine Publishing

Nelson, S. (Compiler) (2001) The Pacific Coast Rhododendron Story American Rhododendron Society. Binford & Mort Publishing, Portland, Oregon.

University of Washington: Pruning and Caring for Rhododendrons. 

Washington Native Plant Society (2022) Coast Rhododendron: Washington’s State Flower 

World Meteorological Organization (2025) January 2025 Sees Record Global Temperatures Despite La Niña

ABOUT THE AUTHOR:
Sonja Nelson is a Skagit County WSU Extension Master Gardener, Class of 2009.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Is Bamboo for Your Garden?

If you love bamboo, be a good neighbor and understand how to select, grow, and maintain the plant.

By Kay Torrance, Skagit County WSU Extension Master Gardener

Bamboo is alternatingly loved and hated by home gardeners. Typically, gardeners are firmly planted in one camp or the other. Full disclosure: I love bamboo. With its soft green glow and exotic sculpted leaves rustling in the breeze, the impact of bamboo in a garden can be transforming. It invokes tranquility and quiet contemplation. Bamboo is unlike any other plant in the garden.

Bamboo resists drought, deer, pests, and disease.  As a landscape plant, it is self-mulching and evergreen. It grows well in poor soil. With all this going for it, why do so many cringe at the thought of growing bamboo? Bamboo has a reputation for being invasive and difficult to maintain. Is that a tired stereotype? Bamboo is not maintenance-free, few plants in the garden are. It requires at least annual maintenance and more extensive care every 3-4 years. Much less than a fruit tree but more than a cactus.

Often, bamboo is planted as a fast-growing evergreen privacy border, with the expectation that no pruning or maintenance will ever be needed once it is grown. Is that reasonable for any plant? Before planting, was the selected bamboo evaluated to see if it had a clumping or running habit? Whether it was short or timber-sized? The key to being in zen with your bamboo is understanding how to select, grow, and maintain the plant.

Phyllostachys Edulis ‘Moso’ is a common timber variety growing in Arashiyama Bamboo Forest in Kyoto, Japan. Photo © Bobbi Lemme

Phyllostachys nigra ‘Black Bamboo’ showing smaller canes from the purchased nursery pot in the back and the new larger green culms produced two years later. Photo © Kay Torrance

What is Bamboo?
Bamboo is the tallest member of the grass family. Believed to originate in China, over a thousand species are growing worldwide in various climates. Some timber varieties grow over 100 feet tall with culms over a foot in diameter. In lush tropical environments, varieties can grow three feet a day. You can also find bamboo thriving in the snow-covered foothills of the Himalayas. Most bamboos originate from Asia, but several species of the genus Arundinaria are native to the Southeastern US.

Botanically, the plant is an evergreen perennial. Like all grasses, it has a woody ringed hollow stem known as a culm (commonly called canes). The joints along the culms are called nodes, and branches grow out above the nodes. The plants have an underground stem called a rhizome, and roots are clustered along the rhizome. New plants erupt from rhizomes as buds. These are called shoots once they emerge from the ground. New culms are protected by papery sheaths, which fall off when they mature and harden.

Not only is bamboo beautiful, it is functional. Strong enough for buildings, furniture, and fences, it is still used today in Asia as scaffolding to build skyscrapers. It is a renewable resource for home décor, garden stakes, brooms, livestock food, and charcoal. Tender baby culms are a dietary delicacy.

How Bamboo Grows
Bamboo produces new culms from rhizomes in the spring. They grow rapidly for 30 to 60 days, obtaining their full height. Only then will they start producing limbs and leaves. After the spring surge, bamboo does not generally grow taller or produce new culms until the following year. Individual culms can last 5-15 years before dying if not damaged. Bamboo rarely flowers, and it is typically propagated by division.

Bamboo is generally grouped by rhizome growth habits such as clumping or running. Growth habit is the single most important consideration when choosing a variety for your landscape! Clumping bamboos have U-shaped rhizomes that produce culms that are a shorter distance from the parent. Running bamboos naturally spread by sending new rhizomes many feet away from the parent plant. One hears stories of bamboo taking over yards and damaging sidewalks and foundations. To avoid such problems, carefully choose a variety suited to your selected location. Consider pots or containers instead of direct planting.

Newly divided bamboo typically takes 3-5 years to reestablish its root system and produce full-size canes. More vigorous running varieties take less time, and clumping varieties take longer. In an established grove, the new culms are roughly the same size as the existing ones. Proper sunlight, water, and soil nutrition will establish new plants quickly. Adequate watering in the first year is essential while the roots are established.

The growth habit of above-ground branches also varies between bamboos and is important when selecting bamboo for the right look in your yard. Some bamboos suppress branches on the lower nodes, creating a very upright and open appearance. Some are naturally weeping and have a more informal look. Some have a single branch emerging above a node, while others have multiple branches at each node, producing dense foliage. These branches can be pruned, but selecting a variety with the desired growth characteristics is easier than pruning each year.

Qiongzhuea tumidissinoda ‘Walking Stick’ bamboo has enlarged nodes. It is a fun variety that grows up to 12′ (less in a container). It is an aggressive running bamboo, sending rhizomes a long distance from the source, and likes to jump barriers. Best for a container. Photo © Kay Torrance

Bamboo garden and planter studio. Photo courtesy of Bamboo Garden Nursery

Varieties and Selection
The American Bamboo Society lists almost 500 kinds of bamboo grown in the US and Canada. Sizes vary from under a foot to over 100′ tall. Many bamboos have gold, blue, red, black, and variegated canes. The nodes can be straight or bulbous, like the walking stick bamboo in Bu Belly or Chinese. There are even varieties with zigzag canes. See the section below for a list of varieties suited for the PNW.

The Pacific Northwest is not an ideal growing location for bamboo. Bamboos grow slower in our cool summers with limited rain. Some bamboos that are invasive elsewhere are not a problem here. For example, Phyllostachys aurea, common ‘Golden’ or ‘Fishing pole’ bamboo, has a reputation for being invasive. However, here, bamboo grows slower than in climates where summer temperatures average 90+ degrees Fahrenheit. If you plant it in the shade, the growth will be slower. A neighbor planted Phyllostachys aurea next to a water garden over 50 years ago. Initially, it thrived, but as conifers grew up around the area, it struggled for light and recently died. Like other grasses, most bamboos can take full sun and will thrive in it. Some prefer part shade. None will grow in full shade.

Is bamboo right for you? Before adding bamboo or any plant to your garden, think about your goals and expectations:

• What do you want to accomplish? Privacy? Texture? Most people select bamboo as a natural evergreen privacy screen or a focal point for their garden.
• How much room do you have? Do you want a forest, a clump, or a pot on your deck? There are varieties appropriate for all of these uses.
• How much maintenance do you have time for? Clumping varieties require less root pruning and are less likely to escape.
• How tall should the plants grow? Although bamboo tolerates pruning well, the resulting boxy look might not be desired. Selecting a variety that matures to the desired height without topping is better.
• Do you want small, delicate leaves that tinkle in the wind or large leaves that rustle? I have a patch of Pseudosasa japonica ‘Japanese Arrow’ bamboo. Its large leaves rustle delightfully in a breeze, growing only to 15′. It provides year-round privacy but is a running bamboo, so its growth needs to be limited with semi-annual root pruning.
• Is there a color preference? In addition to solid green, culms can be yellow, orange, red, blue, silver, or even variegated. Leaf colors can be shades of green, yellow, blue, silvery, and variegated. Beware that many colorful bamboos are from the tropics, so choices for the PNW are limited.
• Do you want pencil-width stalks, medium size, or a diameter measured in inches? If you want a cane that is an inch across, make sure you have room for a forest. If you choose a large-diameter bamboo, you can have bamboo canes for projects around your home. Small-diameter culms can provide endless plant stakes, craft supplies, and weaving material. Having uses for pruned canes makes maintenance enjoyable.
• Are you looking for an open upright structure or a dense natural fence? Running bamboos have more space between the culms and a more upright appearance. Clumping bamboo culms grow more closely together. Some bamboos have more horizontal branches that make a good privacy screen.

Phyllostachys nigra ‘Black Bamboo’ grown against a foundation and contained by a sidewalk at the Elisabeth C. Miller Library in Seattle. In this shady contained location, it will not grow to its unconstrained height of 35′. Photo by Kay Torrance

If you are considering bamboo:

• Avoid buying large (over ½ mature culm size) running bamboo unless you are committed to containing and maintaining it. See maintenance requirements below.
• Avoid planting a hedge of any type of bamboo along a property line for privacy and not building a containment system along the property line to keep it on your side.
• Avoid planting bamboo in areas where there is irrigation or where you fertilize routinely. It will grow fast and require more maintenance. Bamboo planted next to turf lawns will soak in all that water and fertilizer and grow quickly.

Planting and Management
Even though bamboo is likely filling the role of a shrub or tree in your yard, manage it like the grass it is. If you want to contain a plot of grass, you either put a barrier in the ground to redirect the root growth, or you can edge (cut) the roots. The same method is required to contain a stand of bamboo. Bamboo rarely seeds and is surprisingly difficult to propagate from seed. 
Container Planting
The most obvious barrier to preventing bamboo spread is planting it in a pot or container. Like any potted plant, it will need to be thinned every few years or become a root-bound mess. Choose straight-sided pots and use a perennial root-cutting blade to reduce the size. You can build wooden planters with a removable side, making thinning easier. Don’t wait too long. The job just gets more challenging.
Root Barriers
You may have a natural root barrier, such as a rocky terrain or a pond. Despite its tropical appearance, bamboo does not like wet feet. It makes a great companion planting around ponds and will grow best on a small mound, elevating its roots from moisture. You can use a densely forested area as a natural barrier, as bamboo needs some sun. You do not want to plant larger or timber bamboo close to your home, driveway, or sidewalks. Clumping bamboo can also put a lot of pressure on a barrier or pot. Allow room on all sides of the barrier to do maintenance. Don’t install a barrier right on a property line. Set it back about two feet so you can manage the back side.

Most yards do not have suitable natural barriers, so fabricated barriers are needed. Typical bamboo root depth is around 8-12″, with some timber bamboo roots reaching around 18″. A healthy bamboo with vigorous roots will try to dig under or over the top of your barrier, so a barrier height of 24″ is common. Barriers up to 30″ may be required for timber bamboo. If you mound your bamboo, a shallower barrier can work.

You can use metal, wood, or fabric as barriers. Metal will rust and disintegrate over time, and wood will rot. The most long-lasting barriers are either rigid 40 mil HDPE (high-density polyethylene) or flexible EPDM (ethylene propylene diene monomer). Alternatively, you can buy a thick EPDM pond liner and cut it to size. Standard landscaping fabric is insufficient for control. You can buy molded pond liners in various shapes and fill them with dirt instead of water. You will need to cut holes in the bottom so they drain, but don’t cut them too close to the sides.

Barriers will do a good job of containing the bamboo, but you still need to inspect the area during the spring and summer and check for the occasional rhizome trying to go over or under the barrier. The bamboo stand will overgrow its area over 3-7 years and must be thinned. It is best to do this before the roots become a solid mass and are hard to cut. Plan on removing a third of the bamboo every 3 years. Battery-operated or electrical reciprocating saws with long wood or pruning blades make the job easier.

Perimeter Trench
Another method of containment is a loosely filled perimeter trench. Dig an 18″ deep trench about 12-18″ wide around the bamboo location. Fill it with sand, pea gravel, or loose soil. Don’t use soils with silt or clay, as they will compact and harden over time. Bamboo rhizomes will continue to grow and expand freely when they enter the trench. In the fall or early spring, use a spade (the ones with serrated blades work best), root saw, or reciprocating saw with a long blade and work around the perimeter, cutting off and removing any new growth that has entered the trench. Make sure to pull out all of the rhizomes. You do not need to worry about the fibrous roots.

Fargesia nitida ‘Jiuzhaigou’ is a clumping bamboo. This cultivar is ‘Red Fountain’ with pencil sized red canes. Cultivars of this variety can be found with different colored canes. © Photo by Kay Torrance

Fargesia robusta ‘Campbell’ is a clumping bamboo with ¾” canes. © Photo by Kay Torrance.

Removing Shoots and Mowing
Another method of control is simply removing unwanted shoots at the ground level or just below. It is easiest to do in the spring when they are tender. They will not grow back. For smaller-diameter bamboo, you can use your lawn mower to run over unwanted culms anytime.
Pruning the Foliage
Bamboo foliage doesn’t need a lot of maintenance. Varieties with many horizontal branches can be legged up to showcase the culms better. If you need to control the height, bamboo is very tolerant of topping. However, it saves work to choose the right-sized bamboo for your location. 

You should thin the canes every year or two. If the canes are not thinned, the grove can become very dense and vase-shaped as culms compete for sunlight. Cut the canes anytime during the year at or below ground level, removing no more than a third of the canes each year. New canes are not as strong, so thin the oldest canes. Old canes have many uses, so think of this as harvest time.

Rejuvenation or Removal
Rejuvenation often requires removing a large portion of the bamboo grove. The easiest way to kill all or part of the plant is to remove the unwanted canes at ground level or just below it and not let them grow back. Remove bamboo with small-diameter canes with a lawn mower; larger canes will require a lopper or a saw. 

Bamboo needs nourishment from the canes and will die without it. It is best to use this method right after the new culms have reached full height in early summer. The plant has just expended a great deal of energy sending up the culms and will be severely weakened by pruning. It will try to regrow, so make sure to follow up. It can take one to three years before the plant is completely dead. Make sure to shut off irrigation and sprinklers in the area. This method leaves the roots in the ground but they will rot in a year or two.

If you need immediate removal of the plant and rhizomes, the only solution is digging. It is best done when the soil is moist. Cut the canes at one foot (or so) above the ground and use them to help pull out the rhizomes. Get all the rhizomes, but don’t worry about the fibrous roots. As for other methods, there are many: applying chlorine, salt, vinegar, and even gasoline. These contaminate the soil. They may kill the bamboo, but they will destroy the soil ecology and everything nearby. 

Fargesia dracocephala ‘Rufa’ ‘Dragon’s Head’ at the WSU Discovery Garden. This clumping bamboo has a loose weeping habitat so the hedge has been pruned to keep it off the path. Bamboos tolerate pruning well as long as adequate leaves are left for plant health. © Photo by Kay Torrance

Purchasing Bamboo
If you are still reading and anxious to start, don’t rush out and buy the first plant you find. Many nurseries carry only one or two varieties of bamboo. Often, they choose varieties that grow fast and are easily divided, which may not be what you want. 

When choosing plants:

• Avoid plants that are pot-bound with circling roots. These plants will usually have the culms growing right next to the outer edge of the pots, and sometimes, the pots will bulge where the rhizomes are overcrowded.
• Like most plants, a larger pot with more mature culms will establish quicker than a recently divided plant with one or two culms.
• Pay attention to the label. Expect that it will take 3-5 years for plants to reach its established height. The old adage about the first year a plant sleeps, the second it creeps, and the third it leaps is very true of bamboo. It is normal for nursery wholesalers to prune the stalks when dividing or transporting stock, so don’t go by what you see for height.
• Check the label for growing zones. Cold tolerance is important. Some lovely bamboos are marginal for our area. A hard, prolonged freeze might kill them, or they may die down to the ground. If the rhizomes survive, they can take years to recover.

If you can’t find what you want locally, consider mail order. Many bamboo specialty nurseries and Japanese botanical gardens have groves of mature plants for reference. Do research online. There are lots of pictures of bamboo staged with a person for scale. Plan to plant your bamboo in the spring or early summer to establish roots before any freezes. For the first summer, bamboo needs regular water and heavy mulch.

Variety Suggestions

• Fargesia nitida ‘Jiuzhaigou’ is a short and slender clumping variety of bamboo that grows 8-10′ tall. Many colorful cultivars are available, such as ‘Red Fountain’ and ‘Black Cherry’. The canes are pencil-thin with tiny leaves. It has a dramatic vertical growth habit and is very manageable both individually and as a hedge.
• Fargesia rufa ‘Sunset Glow’ is a small clumping bamboo that grows 5-10′ tall with 1/3″ red-orange canes, medium-sized leaves, and a weeping growth habit. Suitable as a shrub in a grouping or a short, dense hedge to provide color.
• Fargesia dracocephala ‘Dragon’s Head’ is a clumping bamboo that grows 8-12′ with 1/2″ canes. It also has a weeping fountain-shaped appearance with medium-sized leaves that sway in the wind. Good for a dense hedge, but allow room for it to lean.
• Fargesia robusta ‘Campbell’ is a clumping bamboo that grows to 12-15′ with ¾” canes. The canes start green but age to a pale yellow. Very upright and tight culm spacing with large leaves. Makes a very dense hedge or large 15-20′ grove. It tends to become vase-shaped if culms are not thinned to allow light to reach the center. Canes are straight and strong.
• Qiongzhuea tumidissinoda, known as ‘Walking Stick’ bamboo, has ½” canes with enlarged nodes. It is only recommended for containers as it is an aggressive and agile runner. It grows 10-15′ but less in containers.
• Pleioblastus viridistriatus is commonly called ‘Greenstripe’ bamboo. It is widely available and grows 2-3′ with tiny canes. It has chartreuse and cream-colored variegation in the leaves. It is unusual because it is deciduous, losing its leaves in the winter. It is a great container plant or tall ground cover. Due to its small size, many people control it with their lawnmower instead of barriers or pruning.

Finally, if you are looking for the impact of a bamboo forest, look for a medium-height running bamboo to plant inside a barrier or container. The iconic Phyllostachys nigra ‘black timber’ bamboo is a good choice. However, the variety is currently undergoing a mass flowering event. Bamboos only flower every 30-120 years, depending on the species. After flowering, the entire plant dies. Since most bamboo is propagated by division, the plants of a particular variety are all identical. They will die en mass worldwide until they return from the notoriously tricky seeds to germinate. That is what is happening now with the beloved black bamboo. For now, if you are looking for the aesthetics of a timber bamboo, try one of the Phyllostachys. The variegated Phyllostachys aureosulcata ‘Yellow Groove’ is a good choice that sports an occasional zigzag cane or perhaps the classic Semiarundinaria fastuosa ‘Red Temple’, for more color.

Is there a blog topic you’d like to learn more about?
Share your ideas with the blog editors in the comment section below.

RESOURCES:

Heinricher, J. and Flemmons, K. (2006) Discovering Bamboo. Boo-Shoot Gardens LLC

Meredith, Ted Jordan (2006) Timber Press Pocket Guide to Bamboos, Timber Press, Portland, OR

Farrelly, D. (1984) The Book of Bamboo: A Comprehensive Guide to This Remarkable Plant, Its Uses, and Its History.Sierra Club Books, San Francisco, CA

Stangler, C. (2001) The Craft & Art of Bamboo. Lark Books; New York, NY

American Bamboo Society. https://www.bamboo.org

WSU Vegetable Research and Extension. https://vegetables.wsu.edu/crops/bamboo/

Kay Torrance

AUTHOR:
Kay Torrance has been a Skagit County WSU Extension Master Gardener since 2019. She is garden coordinator of the Naturescape garden and pond in the Discovery Garden on SR 536 west of Mount Vernon. https://skagitmg.org/home/discovery-garden/

Enjoy a Day Trip to Tour a Pacific Northwest Garden

February is an excellent time to look ahead and plan a visit to one of the many public gardens showcasing a range of plants from native to tropical beauty

By Skagit County WSU Extension Master Gardeners

Creating and appreciating a garden is a dynamic, creative process that benefits from the inspiration of others’ work, traditions, and history. Gardeners in the Pacific Northwest are fortunate to have access to many garden styles and a wide variety of plant combinations at gardens and nurseries that are open to the public – all within range of a day trip from Skagit Valley.

In this article, several Skagit County WSU Extension Master Gardeners share observations from their recent visits to a sampling of regional display gardens. Each author highlights the visit with inspirations ranging from the native rhododendrons of Meerkerk Gardens on Whidbey Island to the amazing cloud forest of the Seattle Spheres.

Perhaps you are hosting visitors this summer or in charge of planning an outing for a group of friends; use these ideas as a springboard for your next garden inspiration. Details for each garden include website links, contact information, logistics, and admission information to help prepare for a visit.

University of Washington Biology Greenhouse Photo © Kay Torrance

University of Washington Biology Greenhouse Photo © Jessamyn Tuttle

University of Washington Biology Greenhouse

Location: Lower level, southwest side of the Life Sciences Building, at 3747 W Stevens Way NE, Seattle, WA. Map

By Kay Torrance, Skagit County WSU Extension Master Gardener

In 2023, a group of Skagit Master Gardeners toured the UW Biology Greenhouse, the Elizabeth C. Miller Library, the UW Botanic Gardens and the Washington Park Arboretum. Though this excerpt focuses on the biology greenhouse, I recommend each of the venues as a treasure trove of plant learning,

The UW Biology Greenhouse is a 20,000-square-foot facility opened in 2022, showcasing over 6,000 plant species. According to the website, the new structure “replaces the original Botany Greenhouse, where the UW’s biology department had amassed one of the country’s most diverse plant collections over a period of 65 years.” Led by docents, the group explored four themed garden rooms: Desert, Tree of Life, Warm Tropics, and Cool Tropics.

The Desert Room features North American cacti and plants from Africa, including a Welwitschia from Namibia. Next, the group walked through the Tree of Life room, where plants are displayed in evolutionary order. Next, the tour moved into the warmth of the Warm Tropics Room, filled with palms, gingers, and orchids. The tour then took the Master Gardeners to the Cool Tropics Room, showcasing high-altitude tropical plants. The greenhouse also includes climate-controlled rooms for research and education, benefiting university students in fields such as plant ecology and landscape architecture.

Read an entire blog article about the 2023 visit to the UW Biology Greenhouse at https://skagitmg.org/visit-uw-botanic-garden/

Website: https://www.biology.washington.edu/facilities/greenhouse

Hours and tours:

• The UW Biology Greenhouse is open to the public from noon to 4 p.m. on non-holiday Wednesdays and 10 a.m. to 2 p.m. on the second and fourth Saturdays of the month-docent-led tours for groups of more than eight people by arrangement.
• The UW Botanic Gardens and Washington Park Arboretum are open daily to the public. https://botanicgardens.uw.edu/

Admission: Free

Contact information: https://www.biology.washington.edu/facilities/greenhouse/contact

Amazon Spheres Photo © Laura Kuhn

The Seattle Spheres

Location: 2111 7th Avenue, Seattle

By Laura Kuhn, Skagit County WSU Extension Master Gardener

The Seattle Spheres is a private biosphere space created at Amazon headquarters near downtown Seattle in 2018. The space, which includes three glass-enclosed spherical conservatories, is open by reservation only to the public on the first and third Saturdays of each month.

This lush and beautiful facility supports a cloud forest environment – think rainforest tree canopy – supporting flora ranging from tiny begonias and orchids to large tree ferns and aloes. A highlight is the “living walls” that boast over 25,000 plants woven into 4,000 square feet of mesh in what the organization calls an “innovative demonstration of biodiversity.” Trees are planted in pots in the Canyon Living Wall area, and the vertical gardens are more than three stories tall.

There are over 40,000 plant varieties, with many plants in bloom in a wide range of colors, shapes, and sizes. Visitors may explore four stories of plants accessible by stairs or elevators.

Website: Seattlespheres.com

Hours: By reservation only, open to the public from 10 a.m. to 6 p.m. on the first and third Saturdays of each month. If you do not have a reservation or go to the location on another day of the week, visit the Understory or the Urban Arboretum found outside of The Spheres.

Admission: Free

Contact Information: For details and to make a reservation, go to https://www.seattlespheres.com/the-spheres-weekend-public-visits

Chihuly Garden and Glass

Location: 305 Harrison Street, Seattle

By: Kathy Wolfe, Skagit County WSU Extension Master Gardener

Chihuly Garden and Glass highlights a beautiful combination of the iconic glass works of artist Dale Chihuly set in a vibrant garden showcase. The Glasshouse and adjacent displays and exhibitions opened at the base of the Space Needle in Seattle Center in May 2012.

The stunning Chihuly glass art, coupled with beautiful gardens, is a collaboration that inspires visitors from around the world. Chihuly has worked with public gardens – large and small – in the US and internationally to create colorful blends of plants and glass that meld into complementary natural vignettes. Gardeners can be inspired by the clever combinations of glass and plants.

Depending on the time of year, visitors to the Glasshouse may see a wide range of camellias blooming among dogwood, along with scarlet daylilies and fuchsias, accented by icicle-shaped glass towers and spheres incorporated to embellish the scene. The gardens are transformed seasonally, and a master plant list used by the landscape design team is available on the facility’s website.

In addition to the garden area of the exhibit, ticket prices include the Exhibition spaces containing Chihuly’s glass creations, drawings, large architectural installations, and personal collections. A theater offers a short film on Chihuly’s artwork; a free audio tour is available. The Bar restaurant provides food and beverages; and a bookstore offers a selection of gifts, cards, and books.

Website: https://www.chihulygardenandglass.com

Hours and tours: Hours vary daily, so check the website for details. The venue can be closed for private events. Highlight tours are offered three times daily and included in the price of admission.

Admission: Tickets should be purchased in advance. Prices range from $22 to $37.50 depending on a guest’s age (free for children under four) and the time of year.

Contact Information: For general information, call 206-753-4940 or contact guestservice@chihulygardenandglass.com

Happening now: “Winter Brilliance” is a light and music installation containing more than 700 hand-blown glass forms that runs until February 28, 2025, in Gallery 1.

Elizabeth C. Miller Botanical Garden Photo © Crowell Photography.com

Elizabeth C. Miller Botanical Garden
Photo © Crowell Photography.com

Elizabeth Carey Miller Botanical Garden

Location: 79 Olympic Drive Northwest, Seattle

By Nancy Crowell, Skagit County WSU Extension Master Gardener

In Western Washington gardening history, there are a handful of people all serious gardeners should know about because of their incredible, prolonged influence on gardening in the region. One of those people was devoted horticulturist Elizabeth C. Miller, whose name is now associated with the Elizabeth Miller Library at the UW Center for Urban Horticulture and the Elizabeth Carey Miller Botanical Garden – commonly known as the Miller Garden.

Elizabeth C. Miller Botanical Garden
Photo © Crowell Photography.com

The Miller Garden, which was developed on six acres of Miller’s private home, has established collections and themed areas. However, the key to why a diehard gardener should take a tour here is that this garden is where Great Plant Picks tests and chooses the plants recommended for our Pacific Northwest gardens. The garden’s website describes the Great Plant Picks as “recommendations for a comprehensive palette of outstanding plants for the maritime Pacific Northwest.” The website states that more than 1,000 plants have been selected to date for gardeners living west of the Cascade Mountains from Eugene, Oregon, to Vancouver, British Columbia.

The garden was designated a public garden in trust after Miller died in 1994, unbeknownst to her neighbors in the exclusive neighborhood. As a compromise to neighbors concerned about large numbers arriving in the neighborhood, the garden is limited to 500 visitors a year, and the coveted entry tickets are sold out months in advance. In fact, the entire 2025 tour season is already sold out.

The garden is well established, yet still a work in progress as caretakers update and refresh the original plantings. A tour reveals surprises around every corner. Fall is a favorite time to visit due to the vast collection of established Japanese maples, though a midsummer visit was equally impressive.

Miller and her horticultural adventures are fascinating. Read more at https://millergarden.org/, then toss your name into the tour lottery. I hope you get a call.  

Website: https://millergarden.org/

Hours and tours: All visits to the Miller Garden are by reservation only with a staff member as a guide. The garden website states, “due to an unprecedented response, the 2025 tour season is now filled.” Early bird reservations for 2026 will open in autumn 2025. A “virtual” tour is offered online at https://millergarden.org/the-garden/

Admission: Free

Contact Information: To be added to the email list for class or tour date announcements, send a message to info@millergarden.org

Heronswood Photo © Heronswood

Heronswood
Photo © Heronswood

Heronswood

Location: 31912 Little Boston Rd NE, Kingston, WA Note: Ferry wait times to the Olympic Penninsula can be long so make reservations and plan accordingly.

By Anne Hays, Skagit County WSU Extension Master Gardener

Nestled in the charming town of Kingston on the north end of the Olympic Peninsula, Heronswood Garden can feel like stepping into a living dream. This enchanting botanical garden, established by renowned plantsman Dan Hinkley, is a paradise for anyone who cherishes nature’s quiet beauty.

The gardens opened in 1987 and comprise 15 acres and more than 8,000 varieties spread across six distinct yet integrated gardens.

As guests pass through the garden gate, they are immersed in a world where every path leads to a new discovery. Heronswood’s collection of rare and unusual plants is astounding, curated from all corners of the globe. The garden’s thoughtful design blends exotic with native plants, creating a seamless tapestry of textures and colors that change with the seasons.

The garden bursts to life in spring, with rhododendrons in full bloom in a variety of vibrant hues contrasting with the surrounding lush greenery. A fern glade mesmerizes visitors with the delicate interplay of light and shadow.

As one of the state’s “hidden gems,” the gardens offer tranquility and intimacy, allowing guests to wander for hours enjoying the color, listening to the birdsong, and gaining inspiration.

For some visitors, Heronswood is more than a garden-it’s a haven. For plant lovers, artists, and anyone seeking solace in nature, it’s a destination that lingers in the heart long after.

Website: https://www.heronswoodgarden.org/

Hours: 9 a.m. to 3 p.m. Saturday and Sunday. Closed major holidays. Summer opening hours start April 2, 2025.

Admission: $10 for adults, $5 for youth aged 7 to 17, and free for children aged 6 and younger. 

Contact Information: 360-297-9620, Info@heronswoodgarden.org. To learn more about classes and events, go to https://www.heronswoodgarden.org/event

Meerkerk Gardens
Photo © Anne Hayes

Meerkerk Gardens

Location: 3531 Meerkerk Lane, Greenbank, WA (Whidbey Island)

By Anne Hayes,  Skagit County WSU Extension Master Gardener

Nestled just 50 miles from Mount Vernon is Meerkerk Gardens, described as a well-curated “peaceful woodland garden.” The grounds provide a conveniently accessible garden, one of Whidbey Island’s best-kept secrets.

Established by Ann and Max Meerkerk, the grounds include a 10-acre Northwest woodland display garden and 43 woodland acres lined with nature trails. The gardens showcase native flora, including rhododendrons, azaleas, and companion plants, in a variety of garden rooms. Visitors may stroll along the curving, easy-walking paths through the splendor of rhododendrons galore – featuring vibrant shades of colors from white to pink and vibrant red to purple. Today, the Meerkerk Rhododendron Garden nonprofit manages the gardens and woodlands, established in 2002.

In addition to garden access, the website offers detailed information about seasonal guided walks, concerts, children’s programs, nature classes, rhododendron care classes, and guided tour information. The website also features a bloom report so guests can time a visit to experience the complete joy and bloom of the gardens. The garden features color and texture during all seasons.

A special addition is the onsite nursery, open by appointment only in the fall and winter months, reopening in March on Friday, Saturday, and Sunday.

Website: gardeninfo@meerkerkgardens.org

Hours: Open 9 a.m. to 4 p.m. daily

Admission: $10 for adults and free for children under age 13. Dogs on leash are welcome.

Walks: Guided walks are offered during some seasons, starting at 1 p.m. at the Gatehouse and lasting about 90 minutes. Walks are free for Friends of Meerkerk (and children under 13); the cost is $15 per person for non-members.  Preregister at www.meerkerkgardens.org/events

Contact Information: 360-678-1912

Is there a garden you love or hope to visit soon?
Share your favorite display gardens in the comment section below.

Urban Meadow at Bellevue Botanical Garden Photo © James Gagliardi, Bellevue Botanical Garden Director

Yao Garden at Bellevue Botanical Garden Photo © James Gagliardi, Bellevue Botanical Garden Director

Bellevue Botanical Garden

Location: 12001 Main St., Bellevue, WA

By Diana Wisen, Skagit County WSU Extension Master Gardener

As one of the most beautifully designed public botanical gardens in the United States, the Bellevue Botanical Garden is a “must-see” for anyone who loves gardens in the Pacific Northwest. The garden spans 53 acres in a wondrous mixture of cultivated gardens, restored woodlands, natural wetlands, and native plant collections. The paths lead visitors through hillside rock gardens, ponds, and a stream, through forests, past a gnome door hidden under a tree, and a Chinese garden, all with lovely works of garden art throughout.

Urban Meadow with irises at Bellevue Botanical Garden Photo © James Gagliardi, Bellevue Botanical Garden Director

Visitors will likely see varieties of trees they have never seen before. Visitors may wish to bring a cell phone to use the QR codes on the signage for more educational information about the plants. A small professional staff maintains and manages the garden along with local groups and individuals who donate nearly 20,000 hours a year to maintain the gardens.

The garden is known for its winter light display called “Garden d’Lights” during December, with tickets sold online.

The garden is currently hosting a special traveling exhibit called “The Lost Birds” through September 2025. The display features hauntingly beautiful giant bronze statues of extinct birds placed in a circle.

The Trillium Store gift shop and Copper Kettle Coffee shop both have seasonal hours.

Website: https://bellevuebotanical.org/

Hours and tours: Open daily from dawn to dusk, including all holidays. Free public tours are available on Saturday and Sunday, April through October. Private docent-led group tours can be scheduled online.

Admission: Free. Service animals are only allowed in the garden.

Contact Information: Administrative Office may be reached at 425-452-2750. To contact the Bellevue Botanical Garden Society, email bbgsoffice@bellevuebotanical.org

Skagit County WSU Extension Master Gardener Discovery Garden

Location: 16650 State Route 536 (Memorial Highway), Mount Vernon, WA

By Ginny Bode, Skagit County WSU Extension Master Gardener

The Skagit County WSU Extension Master Gardener Discovery Garden, located on State Route 536 west of Mount Vernon, always amazes visitors. A stop at the gardens is an easy addition to the list of area attractions.

First-time visitors are often surprised by the extensive collection found in the 1.5-acre garden. The well-maintained paths wind through 25+ garden rooms, including a koi pond, an herb garden, a vegetable garden, and many benches for resting. Each garden has a focus on specific plants that thrive in the Skagit Valley.

Visitors will find many educational opportunities and kiosks about growing fruits and vegetables, ornamental and native plant gardening, pollinators, and composting.

The Children’s Garden at Skagit County WSU Extension Master Gardener Discovery Garden Photo © Sue Wren

A highlight is the Children’s Garden, which is filled with colorful plants and whimsical structures. It is a place where children can touch, smell, and explore different textures, as well as vegetable patches and flower beds that encourage curiosity about how food grows and foster a love of nature and gardening.

The Discovery Garden, designed to inspire and educate the public, is maintained by 150 volunteer master gardeners. An annual open house is held in the garden from 10 a.m. to 2 p.m. on the last Saturday in June, featuring a plant clinic and children’s activities.

Adjacent to the Discovery Garden are two additional public display gardens on the WSU NWREC property: the 0.5-acre Salal Native Plant Garden and the 6-acre NW Fruit Garden.

Website: https://skagitmg.org/home/discovery-garden/

Hours: Open daily during daylight hours

Admission: Free

Contact Information: For information, go to https://skagitmg.org/home/discovery-garden/

THANK YOU TO THE AUTHORS:
Kay Torrance, Laura Kuhn, Kathy Wolfe, Nancy Crowell, Anne Hays, Diana Wisen, and Ginny Bode with the introduction by Kari Ranten. All are Skagit County WSU Extension Master Gardeners who love visiting and finding inspiration in display gardens near home or on holiday.

The Winter Garden: A Study in the Beauty and Resilience of Nature

Winter is an opportunity to plan and add four-season interest to the garden

By Ginny Bode, Skagit County WSU Extension Master Gardener

As winter settles over the Pacific Northwest, the vibrant hues of autumn give way to a quieter, more reflective landscape. While some see the garden in winter as a barren space, this season offers a simpler beauty, one where structure and form take center stage. In this season of rest from the work of gardening, the structural silhouettes of deciduous trees and shrubs reveal the garden’s architecture, offering a fresh perspective on plant arrangement. By emphasizing the bones of the landscape, winter highlights the artistic potential of bare branches, textured bark, and the subtle interplay of light and shadow while showcasing the resilience of nature. This winter, look at your garden’s potential and where you can contribute to the winter beauty by adding a tree, shrub, or grasses.

When we think of design structure, we often first consider architectural or sculptural elements, such as a gazebo, fountain, trellis, or archway. However, evergreens and the bark and branches of deciduous trees and bushes also provide visual structure. These stand resilient, offering rich hues contrasting against the faded tones of fall decay.

In her book Designing and Creating a Winter Garden, Sally Gregson calls evergreens “a green beacon signifying that life continues despite the washed-out decline.” Evergreens provide a living structure to the garden with lush foliage while offering shelter for wildlife. We may think of evergreens as towering trees, but evergreen is a broad term that includes small to medium-leaved and needled shrubs in hues of true green, blue-green, and yellow-green.

This red Acer maple provides a striking winter contrast to the surrounding evergreens. Photo © Skagit Valley Master Gardeners

The twigs of the ‘Midwinter Fire’ Bloodtwig dogwood (Cornus sanguinea) put on a vibrant show of color in the winter. Its yellow-golden fall foliage gives way to stems that transition from yellow at the base to fiery orange and crimson at the tips. Photo © Skagit Valley Master Gardeners

Though bare in winter, deciduous trees and bushes reveal their graceful shapes, adding vertical lines and depth. Together, evergreens and deciduous trees and bushes create a dynamic framework, enhancing the garden’s visual interest and serving as a backdrop for seasonal changes.

Study your garden and those you drive by for structure and winter interest. At this time of year it is easy to see the subtle colors and textures and how the shapes work together. Note which vistas seem balanced and why and which seem blank and could use attention. Take pictures to remember plants and vistas you like. Maybe the solution is a statue, panel, or an evergreen. It may take some trial and error, but with some planning now, you’ll be ready to plant this coming spring or fall. Your reward will be an interesting and beautiful garden, even during the shortest days of winter.

Beyond the overall structure of the garden, if you love nature’s details, the winter garden will not disappoint. Enjoy the bare branches as they form elegant silhouettes. Take a close-up look at the intriguing patterns that emerge on the bark of many trees after the first frost. Acers (or maples,) birches, crape myrtles (Lagerstroemia indica), and ornamental cherries are known for their rich colors and unique textures in winter.

This paper-bark maple (Acer griseum) in the Discovery Garden features striking, cinnamon-colored bark peels in thin, papery layers, creating a textured, sculptural effect that adds year-round visual interest to any landscape. Photo © Skagit Valley Master Gardeners

Grasses add visual interest and movement, offering a gentle symphony, reminding us of nature’s resilience. Photo © Skagit County Master Gardeners
Grasses Add Magic to the Winter Garden
Another way to add winter interest is with ornamental grasses, such as placing shorter, smaller grasses outside a window or near an entry to be enjoyed daily. Their slender textural forms sway gracefully in the crisp air as their frost-kissed blades shimmer with delicate crystals.

Many gardens feature taller ornamental grasses like Miscanthus and Panicum, which show off their feathery plumes as the wind rustles through their stems. These hardy plants contribute to the garden’s aesthetic and provide shelter for birds and other wildlife. In the winter garden, grasses embody elegance and strength, showcasing nature’s artistry every season.

Nandina, often called Heavenly Bamboo has vibrant green leaves that turn a deep red or purple in the fall and winter with clusters of red berries, adding a burst of seasonal color. Photo © Ginny Bode | Skagit County Master Gardeners

For those that like the look of holly without the invasive aspect, Mahonia commonly known as Oregon grape, is evergreen and produces lovely yellow flowers followed by berries. It is deer resistant. Photo ©: Ginny Bode | Skagit County Master Gardeners 
Berries and Hips
Many ornamental shrubs and bushes produce colorful berries or hips at the end of the blooming season. As fall gives way to winter, these berries and hips become more vibrant against the limited tones of the dormant winter garden. The bright red, orange, or purple berries of these hardy plants, which include holly, winterberry, beautyberry, and roses, contrast beautifully against evergreen foliage and snowy landscapes. Beyond aesthetics, berries and hips also provide valuable wildlife habitat, attracting birds and pollinators. These plants thrive in our region’s mild, wet winters, offering a long-lasting seasonal display and contributing to a garden’s biodiversity.

Choose a berry-producing bush for the winter ornamental garden with care. Many hollies have become invasive in our area, popping up where birds dropped the berry seeds. David Zuckerman, UW Botanic Gardens Manager of Horticulture, says, “Just don’t plant English holly (Ilex aquifolium), the species with the dark, glossy leaves and bright red berries that most people picture when they hear the word ‘holly.’ This non-native species has become invasive here and isn’t recommended for home gardens, … leave it to the professional growers.” More than 400 varieties of large and small hollies grow well in western Washington; many can be seen at the Washington Arboretum in Seattle, home to the second-largest holly collection in the US. Remember, hollies are dioecious, meaning female plants require a male plant in proximity to produce berries.

Another berry-producing bush is Nandina, commonly known as Heavenly Bamboo. Often used in public plantings, this versatile shrub has striking foliage and berries in winter and offers a beautiful backdrop as the seasons rotate. Its vibrant green leaves turn a deep red or purple in the fall and winter with clusters of red berries, adding a burst of seasonal color. In the spring, Nandina produces small white flowers, followed by bright red berries in late summer through winter. Drought-tolerant and low-maintenance, Nandina thrives in various soil types, making it ideal for borders, hedges, and decorative accents.

Rosa rugosa provide beauty in the winter as well as the summer garden. They offer a range of benefits that contribute to a garden’s ecosystem by providing food for pollinators and animals. Photo ©: Ginny Bode | Skagit County Master Gardeners 

Callicarpia berries provide winter food for mammals and birds, and the spring flowers produce nectar for the bees-a multi-season winner in the garden landscape. Photo ©: Ginny Bode | Skagit County Master Gardeners 

Many berry-producing shrubs and bushes reach a beauty crescendo in the winter. The deciduous Purple Beautyberry (Callicarpa dichotoma) puts on a stunning show of iridescent purple berries beginning in fall and hanging on well into winter. This deer-resistant shrub has large and small varieties and is an excellent choice for the garden’s ecosystem. Callicarpia berries provide winter food for mammals and birds, and the spring flowers produce nectar for the bees-a multi-season winner in the garden landscape.

Rose hips also provide striking color in late fall and winter. All roses produce hips, some that are particularly large and striking. These vibrant, berry-like fruits develop at the end of the blooming season, by not deadheading the blooms and allowing the hips (or seeds) to develop. Rose hips are both beautiful and beneficial to the garden. Their unique shape and bright hues also attract birds and wildlife, adding ecological value. By choosing a rose specifically for the rose hips it produces in fall and winter, you are adding an extra season of beauty to the garden.

Planting for the Earliest Signs of Spring
Some of us can’t resist the joy of plants which signal winter is waning. Witch hazel (Hamamelis) is the first to show spring is coming, with its bright, spidery yellow or orange flowers blooming when it still seems most definitely winter. The fragrant blossoms offer a cheerful burst of color against still-bare branches, telling us warmer days are coming.

Camellias and winter-blooming rhododendrons are also prized for their vibrant flowers while the days are still grey and cold. Camellias, often in shades of pink, red, or white, thrive in mild climates and add color to winter landscapes. Winter-blooming rhododendrons such as “Christmas Cheer”, with its striking clusters of blooms, bring color to gardens even in snow.

Witch Hazel, genus Hamamelis puts on a glorious show in early February. Photo © Bobbi Lemme | Skagit County Master Gardener

As you can see, the possibilities for adding winter interest in the garden are numerous, with many offering the bonus of providing food and shelter to birds and mammals in the winter. Use the grey days ahead to make a plan for adding structure and beauty to your winter garden next year.

~ ~ ~

Beyond the trees, shrubs, and grasses mentioned here, previous master gardeners have written about other winter garden favorites. Use these links to read more about:

Hellebores: A Treat for Your Winter Garden >

Heaths and Heathers >

Early Blooming Bulbs: Plant Now for Early Spring Color >

We would love to hear about your favorite winter interest plants in the comments section below.

REFERENCES AND RESOURCES:

Gregson, S. (2022) Designing and Creating a Winter Garden. The Crowood Press, Ltd. Ramsbury, Marlborough, Wilshire UK

Bourne, V. (2006) The Winter Garden. Castell Illustrated, Ltd, London, UK

10 Winter Flowering Shrubs. (2023) King County Master Gardeners. Retrieved from: https://extension.wsu.edu/king/tip-sheet-10-winter-flowering-shrubs/

Jorganson, J. Winter blooming Shrubs for the Pacific Northwest. Fine Gardening Magazine. Retrieved from: https://www.finegardening.com/article/winter-blooming-shrubs-for-the-northwest?srsltid=AfmBOorju8siP5rtb-DIJi3T6zmcodZhDDS8zDpxT70pNmo0eJ471Ck6

Smith, T.S. (2024) Top roses to grow for rosehips. Retrieved from: https://www.gardensillustrated.com/plants/winter/rosehips-how-to-grow-garden-rose

Jones, C. (2023) American Beautyberry-An Elegant Native Plant. Retrieved from: https://directnativeplants.com/american-beautyberry-an-elegant-native-plant/?srsltid=AfmBOooEqqq2BtXQ7HPEVsNQhVtFctuiGCRcAu1qj0_RnZCxyxoXMIUJ

Damiano, J. (2023) Give Your Garden a Pop of Color this Fall with Rose Hips. Retrieved from: https://www.morningagclips.com/give-your-garden-a-pop-of-color-this-fall-with-rose-hips/

Hollies for the Puget Sound Area. Retrieved from: https://depts.washington.edu/hortlib/pal/hollies-for-the-puget-sound-area/

Ginny Bode

ABOUT THE AUTHOR:
Ginny Bode is a Skagit County WSU Extension Master Gardener Class of 2022 and is co-editor of the Ask a Master Gardener Blog. She enjoys taking close-up photos of winter beauty on daily walks and in nearby gardens.

Hypertufa Troughs Serve as Lowland Homes for Native Alpine Plants

Grow these tiny gems seen on an alpine hike

By: Sonja Nelson, Skagit County WSU Extension Master Gardener

Nestled low to the ground among the peaks of the North Cascade Mountains are tiny alpine plants that delight hikers as they stroll the high country of Skagit and Whatcom Counties. If these hikers are also gardeners, it is tempting to dig a few of these gems to take home and plant in their home garden. Digging and removing plants is, of course, prohibited on public lands, including national parks, forests, and recreational areas. Moreover, the plants most likely would die when snatched out of their high-altitude environment and planted in the soils found in the lowlands of our ecoregion.

However, alpine gardening enthusiasts have found a solution to recreate the beauty they see in the alpine regions of the North Cascades. Using containers created to grow plants away from their native environment and plants purchased from nurseries specializing in alpine plants, gardeners can successfully grow these tiny gems seen on an alpine hike.

The containers, called “hypertufa troughs,” are constructed to provide the specific requirements alpine plants and succulents need to thrive. They also blend nicely into a garden or can be placed on a deck or patio.

Hypertufa trough planted with mountain heathers native to the North Cascades. The trough is placed on a deck in Bayview in Skagit County. Photo © Sonja Nelson

Snow covering the mountain heathers trough, pictured in Photo 1 (to the left), acts as insulation just as it does for these plants in their native home in the North Cascades. Photo © Sonja Nelson

Hypertufa troughs originated from the naturally occurring tufa rock, a type of limestone formed when carbonate minerals precipitate out of water and build up around organic matter, eventually decomposing, leaving a porous rock. English farmers of the 1800s chiseled feeding troughs for their animals out of this rock. Years later, creative gardeners adopted these old containers, covered in moss and worn by decades of exposure to the elements, as decorative planters. A few of these sought-after antique troughs are still found in Europe but are often too heavy and expensive to transport across the Atlantic. (1)

Since tufa rock was not readily found and available in the US, gardeners in the 1930s-1940s began to make tufa-like troughs using a mix of ingredients with Portland cement. They called them “hypertufa.” (2)

Growing small alpine plants in hypertufa troughs has many advantages. The trough materials serve as insulation against extreme hot and cold temperatures that can occur in our ecoregion. The troughs also drain well, so standing water is never a problem, and the roots of alpine plants grow into the porous hypertufa and tend to thrive.

In addition, the Portland cement in the hypertufa mix slowly releases some calcium and magnesium that plants need. And, because the trough is relatively lightweight, they can be moved from place to place in the garden for the best exposure through the seasons. (2)

Ecoregions
Growing alpine plants in hypertufa troughs gives gardeners the pleasure of seeing them close to home in their gardens and protects them from the possible ravages of warm summers in their native locations.

Skagit Valley is located in the Puget Trough ecoregion, with mild, wet winters, and warm, dry summers. Here, precipitation averages 40 inches per year, with a mean January temperature of 39° F and a mean July temperature of 65°F. This climate differs from the climate of the North Cascades ecoregion, where many of our Washington native alpines for our hypertufa troughs grow in the wild. High elevations in the alpine regions are often covered with snow for many months. (3) The North Cascades Highway (State Route 20) traverses this ecoregion’s subalpine and alpine sections.

The Plants
The choice of North Cascade alpine plants for troughs is considerable. To get started, as an example among alpine plants, choose from the mountain heathers, the saxifrages, and the gentians.

White mountain heather (Cassiope mertensia) near Mt. Shuksan in the North Cascades. © Sonja Nelson

Mountain Heathers
The common name “heather” can refer to many different highland species throughout the world. North Cascade heathers are called “mountain heathers” and include the genera Cassiope and Phyllodoce. Common names include white mountain heather, Alaskan mountain heather, pink mountain heather, and yellow mountain heather. (6)
Saxifrages
Members of the genus Saxifraga are widespread in the North Cascades, many of which grow in the subalpine and alpine regions. Examples seen by the author are Tolmie’s saxifrage (Saxifraga tolmiei) at Chain Lakes, Alaska saxifrage (Saxifraga ferruginea) at Twin Lakes, and western saxifrage (Saxifraga occidentale) on Chowder Ridge (Pojar and Mackinnon1994).

Saxifrage at Bagley Lakes in the North Cascades. © Sonja Nelson

Broad-petalled gentian (Gentiana platypetala) at Cutthroat Pass in the North Cascades. © Sonja Nelson

Gentians
Members of the genus Gentiana are also widespread in the North Cascades. Four gentian species are native to the North Cascades: king gentian (Gentiana septum), broad-petalled gentian (Gentiana platypetala), swamp gentian (Gentiana douglasiana), and alpine bog swertia (Swertia perennis). (6)

Although hypertufa troughs are highly suitable for growing alpines at low elevations, many small native plants and succulents also find the troughs an amenable environment for growth and a refuge from fluctuating temperatures.

Growing Mix
The soil mix used in the troughs cannot be the same as the soil in your garden. Alpines especially need good drainage, which means water seeps through the medium quickly and does not pool around the plant crowns.

A basic trough medium recipe is 2/3 to 3/4 by volume potting mix with either peat or coconut coir and 1/3 to 1/4 by volume coarse perlite. Add fertilizer if the soil mix does not include it. (2)

The extensive Trough Courtyard at the UBC Botanical Garden in Vancouver, BC features an extensive collection of alpine rock plants. © Ginny Bode

This tiny Brassicaceae is tucked between rocks in a trough garden at the UBC Botanical Garden. © Ginny Bode
Making Hypertufa
Recipe mixes for hypertufa can be found on the Internet. The recipe below is from Rosemary Read, Editor of The Social Gardener for the Whatcom Horticultural Society.
Lightweight Frost-proof Troughs “Tufa”
by Rosemary Read, Editor, The Social Gardener

Materials Needed (parts by bulk):

• 1 part Portland cement
• 1 ½ parts fine peat (screened)
• 1 ½ parts horticultural vermiculite and/or perlite
• 2 cardboard boxes (which, when fitted one inside the other, leave a gap of approx. 2 in. between the sides.)
• 2-3 wood dowels (approx. 2 in. long)
• Chicken wire (or metal strips) for reinforcement

Peat Moss and Sustainability

Increasingly, master gardeners are looking towards sustainable materials and encouraging gardeners to use a peat moss substitute whenever possible. Coconut coir is a sustainable product, and can be used instead of peat moss at a ratio 1.5:1 of the coconut coir and cement to water and perlite. However, it does not decompose as quickly as peat moss, which leaves pits and crevices and resembles true tufa rock. The full recipe and directions for using a peat substitute can be found here > 

Download the full report debunking the myth of the sustainability of peat bogs by Linda Chalker-Scott, PhD., WSU Extension Urban Horticulturist and Associate Professor.
Download here>
Steps to Making a Hypertufa Pot
Mix the dry ingredients and add water to make a thick, creamy consistency that can be poured. Mix in an old wheelbarrow, bucket, or container that can be moved and washed out when the project is complete.

1) Set up the outer mold cardboard box where you can move around it freely and where it may be left to harden. It is best to cover surfaces with plastic.

2) Pour mixture into the floor of the outer mold (2″ or more).

3) Press the wooden dowels into the mixture. In addition to making drainage holes, the dowels will support the inner box.

4) Place the inner mold on top of the dowel plugs.

5) Place in chicken wire (along sides and corners).

6) Pour in the mixture until it reaches the top.

7) Leave 24 hours. Remove the outer mold (peel off).

8) Rough sides to make it look “old” (chisel).

9) Leave the inner mold longer to harden.

10) Leave trough a week or more to harden before knocking out the plugs.

11) Leave the trough for 2 weeks to “cure” by soaking it in water, which is changed every 2-3 days.

_______ – _______

Safety Warning: Concrete contains chemicals that can cause skin irritation and lung damage. Read the warning labels on the material purchased. When working with concrete, always wear gloves, a facemask, safety glasses, and old clothing. Set up your work area outside, away from breezes, children, and pets.

_______ – _______

Outer box: 16 ½” x 13 ¼” x 8″
Inner box: 13″ x 9 ¼” x 6-8″
Trough Size (inside): 13″ x 9 ¼” x 5 ½”

REFERENCES AND RESOURCES:

1. Carpenter, J. How to Make a Hypertufa Garden Trough. Retrieved from: This Old House.com

2. Chips, L. (2018). Hypertufa Containers. Portland, OR, Timber Press

3. Ecoregions in Washington, Landscape America, (http://www.landscope.org/washington/natural_geography/ecoregions/).Read, R., Personal Communication, (May, 2024). Lightweight Frost-proof Troughs “Tufa” The Social Gardener, Whatcom Horticultural Society, Bellingham, Washington.

4. Reed, W. High and Dry for a NW Icon. (2023, Fall). Washington State Magazine
Retrieved from: https://magazine.wsu.edu/2023/07/31/high-and-dry-for-a-nw-icon/

5. Pojar, J., MacKinnon, A. (1994). Plants of the Pacific Northwest Coast: Washington, Oregon, British Columbia and Alaska. Tukwilla, WA, Lone Pine Publishing.

Sonja Nelson

ABOUT THE AUTHOR:

Sonja Nelson is a Skagit County WSU Extension Master Gardener, Class of 2009.

Questions about home gardening or becoming a master gardener may be directed to:  Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Know & Grow
Gardening for Fragrance
Presented by Diana Wisen
Free
Tuesday, June 18 ~  1 p.m.
NWREC Sakuma Auditorium
16650 State Route 536, Mount Vernon

Visit the annual Open House at the Display Gardens:

Saturday, June 29
10 a.m. to 2 p.m.
Free Admission & Parking
Discovery Garden
16650 State Route 536, Mount Vernon
Learn More >

A Second Act for Your Square 1-Gallon Pots at the Discovery Garden!

Bring your leftover square 1-gallon pots to the Discovery Garden (16650 State Route 536, Mount Vernon). The bin for recycling the square 1-gal pots is located in the parking lot, just north (to the right) of the main entrance.
We only need square 1-gallon pots like the ones pictured below (bottom right). The recycling bin will be available now through fall. Simply put your pots into the bin, and we take care of the rest!

The Tents are Coming-No Cause for Alarm

Caterpillars signify new, rejuvenating life

—

By: Virgene Link-New, Skagit County WSU Extension Master Gardener

Egg case. © Virgene Link-New

Perhaps it is our fatigue, our weariness with the darkness of winter. Or maybe it’s our eagerness to see the lush new green of spring bursting forth that fuels our distress and disappointment over the early spring appearance of caterpillar tents in our trees.

Do not despair. Those tents are a sign of another type of life bursting forth: one that will replenish soil over-watered by winter rains and feed many species who have suffered from hunger during the winter. Those tents indicate the under-appreciated western tent caterpillar, Malacosoma californicum. There is also a forest tent caterpillar that is less common, Malacosoma disstria. The first is our most common tent maker in this region. Others are called webworms or tussock moths.

Their egg cases were deposited on deciduous trees and shrubs last year in the late summer and early fall. An egg case is many eggs “glued” together to form a “mass.” In the case of the tent caterpillar, it looks like a silvery Styrofoam mass when fresh. As the temperature warms, the eggs begin to hatch. The newly emerged hatching caterpillars spin a silken web to provide themselves with some protection from predators and weather. At first, they feed inside the tent, then they enlarge their tent as they grow. Since these caterpillars feed in early spring, the young leaves they consume are essentially recycled into compost that rains down to replenish the soil. The host tree has enough time to grow new leaves after the caterpillars have departed. Often, you see caterpillar tents in trees that later fail to develop. This is probably due to weather or other factors like disease or fungus.

As they grow, the caterpillars eventually leave the tent and wander about, searching for more leaves to eat and a place to spin a cocoon. They undergo complete metamorphosis, the process of changing from an immature form to an adult form. At this time, they are more easily preyed upon by other insects, spiders, birds, small mammals, reptiles, and amphibians. Even their cocoons can be food for other species. Once they have emerged as moths to mate, they are more easily consumed by birds and bats. They are also vulnerable to viruses, diseases, and fungi.

Now, if you are in business and your livelihood depends upon fruit production or tree production, then action is necessary as energy is spent on producing more leaves. Also, the tents can interfere with setting of fruit. Orchardists act in the winter to remove the egg cases by peeling them off or pruning them out of the branches. The removed egg cases can be harmlessly dropped directly on the ground, which makes them available to predators like ground beetles and centipedes and allows any natural enemies whose parasitized eggs have been deposited in the egg case to exit!

Tent caterpillar egg sack on fence © Pascale Michel

If you have a small, just-planted tree, you should do the same action as the orchardist since unestablished trees are more vulnerable to stress. Or an ornamental tree by your front door would be aesthetically displeasing with tents, and you might want to take some action in that case. If you’ve missed the window for removing the egg cases, the web with caterpillars inside can be pulled off or pinched when cool or in the evening if pruning would distort your desired shape. These mechanical removal methods are more environmentally friendly than the use of pesticides and do not result in chemical run off during rainfall that eventually reaches Puget Sound. As a reminder, please do not use a torch to burn the tents, as fire is more damaging to the plant than defoliation.

Larger trees will put out new leaves and should be less vulnerable to attack the following year as they seem to develop some resistance. Weakened trees are partially killed only when severe infestations (total defoliation) are combined with drought or other stressors (like disease). In forests where trees are too overcrowded for nutrients and moisture, this is a form of natural thinning.

These past several years, the Pacific NW has been impacted by drought. Although tent caterpillars do not impact conifers (evergreens), their obvious dead tops in our landscape indicate that our trees suffer from a lack of water.

To protect the trees in your landscape, ensure they receive at least one inch of water per week out to the drip line. This is one reason the WSU Extension Master Gardener program recommends not having grass or plantings directly under your tree. You can use a moisture meter to read the depth to which water (rainfall or supplied) is reaching.

Our native trees have evolved with our native insects and thus have a symbiotic relationship that benefits the entire food web. Particularly, the tent caterpillar seeks out red alder in the native forest. Other host plants are those in the rose, birch, and willow families, to name a few.

Later in the year, we hardly notice the trees that hosted tent caterpillars, as we’ve forgotten which trees were defoliated in the abundance of new leaves. Please be tolerant of some damage because this species plays an important role in the ecosystem.

REFERENCES AND RESOURCES:

Eighme, L. (2009) Insects of Skagit County, Skagit County Master Gardener Foundation, pp17-18 & p124. https://skagitmg.org/wp-content/uploads/Public Pages/Library/Insects_of_Skagit_County_Eighme_2022.pdf

Colman, S., Antonelli, A., Murray T. “Tent Caterpillars” Washington State University Extension, December 5, 2022. https://hortsense.cahnrs.wsu.edu/fact-sheet/4377/

Tallamy, D. (2019) Bringing Nature Home, Updated and Expanded: How You Can Sustain Wildlife with Native Plants. Timber Press, Portland, Oregon

Western Tent Caterpillar, U.S. Forest Service, 2011.
https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5303047.pdf
Drought Information and Resources. Washington State Department of Agriculture
https://agr.wa.gov/departments/land-and-water/natural-resources/water-quantity/drought-infoThe Ultimate Guide to Mulching Around Trees. The Eco Tree Company, Madison, WI. April 21, 2021.
https://ecotreecompany.com/how-to-put-mulch-around-a-tree/
Bruner, J. (1993) Tent Caterpillar, WSU Fruit Tree, Washington State University
https://treefruit.wsu.edu/crop-protection/opm/tent-caterpillar/
Tent Caterpillar IMP Strategy Fact Sheet
https://www.seattle.gov/documents/Departments/SPU/SWAC/TentCaterpillarIPMFactSheet.pdf

Koszarek, L. (2023) Moths: The Forgotten Pollinators. Penn State Extension Master Gardener, College of Agricultural Sciences, Penn State University, University Park, PA Retrieved at: Moths-The Forgotten Pollinators

Upcoming Skagit Master Gardener Foundation Events:

Master Gardeners at SICBA Home & Garden Show
March 22 – 24 at the Skagit County Fairgrounds
Visit our booth, see our displays, and talk with master gardeners about how to make your garden more beautiful and productive. Learn about free events and programs for home gardeners in Skagit County.
Food Innovation – Food Waste Prevention – Free
April 6, 9 AM to 12PM at the Port of Skagit
Celebrate Food Waste Prevention Week. Check out the worm composting bin, attend food waste prevention classes. Talk to the Skagit Gleaners. The WSU Breadlab sale starts at 10 AM. Event held at the Extension Office on 11768 Westar Lane, Burlington.
Know & Grow: Growing Roses in Skagit County – Free
April 16, 1 PM at the NWREC Sakuma Auditorium (16650 State Route 536; Mount Vernon) Presented by Virgene Link-New
Skagit County Master Gardener Plant Fair – Free
May 11, 8 AM to 2 PM at the Skagit County Fairgrounds
Learn More >

ABOUT THE AUTHOR :

Virgene Link-New has been a Skagit County WSU Extension Master Gardener since 2006. She is an avid insect collector and is garden manager of the Rose Garden in the Discovery Garden on SR 536 west of Mount Vernon.

Questions about home gardening or becoming a Master Gardener may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Gardening for Pollinators

A journey of learning

By: Patty Puckett Tingler, Skagit County WSU Extension Master Gardener

Pollen is a fine powdery substance, typically yellow, consisting of microscopic grains discharged from the male part of a flower. The term pollinator is not limited to wind, insects, animals, and butterflies. Some unexpected insects such as beetles and moths are also pollinators, performing the critical task of transporting pollen to the female parts of other plants, enabling fertilization and the production of seeds and fruit. Pollinators are vital to global crop production. According to an article published by the U.S. Forest Service, “Of the 1,400 crop plants grown around the world, i.e., those that produce all of our food and plant-based industrial products, almost 80% require pollination by animals.”

It is widely assumed that the honeybee is the predominant pollinator. However, there are many types of bees, solitary and social, and they all play a role in pollination. Typically, in a home garden, you’ll find solitary bees that are not part of a hive; however, all bees play a role in pollen distribution and pollination.

© Patty Puckett Tingler

The Banded Wooly Bear is the larval stage of the Island Tiger Moth. © Virgene Link-New

A honeybee on a kale blossom Caption © Virgene Link-New

Flowers, Fruits, and Veggies

Gardeners should consider choosing plants that will provide pollinators with a variety of feeding choices all season long. Choosing early and mid-spring blooming flowers or bulbs to attract pollinators is a wise strategy. Once the pollinators have been attracted to the garden, vegetables will be bountiful all summer long. Fruit trees in blossom are ready to be pollinated. Be sure to share the bounty with birds later in the season as they were likely part of the pollinator team.

Remember to be patient. Attracting pollinators is laying the groundwork for years to come, so efforts made now will affect the garden and pollinators in the future. Watch and study your space for attractiveness to pollinators as you would for sun and shade. Neighboring plants can repel certain pollinators and you may need to move or rethink what to plant in a particular area to attract the pollinators for garden needs. Gardening for pollinators is a journey of learning and understanding.

The Western Swallowtail has a lifespan of only 6 – 14 days. Caption © Virgene Link-New

Hover fly on dahlia © Virgene Link-New

Attracting Pollinators

If you personally like scented plants then you already know which plants pollinators enjoy. In addition to scent, think of using the open face of a flower as a landing place for the pollinator to rest while gathering and distributing pollen. Whether it’s a bee, a butterfly, or a bird, rest areas will encourage different pollinators to return. In the Pacific Northwest, especially western Washington, pollinators are lured by crocosmia, coneflowers, lavender, catmint, and sunflowers to name a few. One easy-to-grow pollinator-friendly annual is lacy phacelia, also known as blue tansy. It is a beautiful lavender color, grows easily from seed, and bees will flock to this plant. Distribute the seeds around your yard and enjoy its tall, beautiful splendor.

The number of scented plants in the Pacific Northwest is quite wide, from climbing vines like honeysuckle to lavender and lilac bushes. There are plenty of native species to choose from that are drought tolerant once established such as camas, lupine, salvia, and checker mallow also known as Malva. Daisies, asters, California poppy, catmint, and sage are also pollinator-friendly plants easily grown in the PNW.

What can we do to support pollinators?

How we can best support pollinators depends on the season. In fall, it’s best to put down your rake and leave the leaves on the ground. Mother Nature will do her best to push the leaves together under shrubs or against a structure. Some pollinators burrow under these leaf accumulations to overwinter. Wait until the spring weather is warmer (above 50°F) before cleaning up the garden as the pollinators will need the warmth as they emerge from their winter habitat.

Lorquin’s Admiral butterfly © Virgene Link-New

Reduce the areas of grass on your property by adding shrubs, trees, and perennials that will provide visual interest and habitat for birds and insects. Use fewer toxins and chemicals, when possible. Pollinators need water for many purposes, including drinking, cooling, and reproduction so be sure to provide a source of shallow water near pollinator plants. Recycle pots or repurpose other containers (buckets, watering cans, birdbaths, etc.) on your patio or landscape to encourage more pollinators. Secondhand stores are full of items waiting for a reimagined purpose.

By providing backyard habitats or even a patio garden of scented, open flowers, bees and other pollinators will find your offerings. Support them by providing plants that help them do their job. Look online for native Pacific Northwest plants, shrubs, or seeds. Visit a local nursery to get plant recommendations or attend classes. Use your local library to learn more about creating or filling your garden with pollinator-friendly plants.

The more you learn about the world around you, the easier it is to live simply with our environment. Becoming aware of your environment and learning more about pollinators will open your eyes to the beauty and intricate connectivity of nature. We co-habit with and need insects, birds, butterflies, and other creatures to act as pollinators to plants to provide us with both beauty and nutrition. Our health, both physical and mental, would not exist without the efforts of the earth’s pollinators.

REFERENCES AND RESOURCES:

Why is Pollination Important ? U.S. Forest Service
Retrieved from https://www.fs.usda.gov/managing-land/wildflowers/pollinators/importance

James, D. Pollinators retrieved from https://hortsense.cahnrs.wsu.edu/pollinators/

Krischik, V. Pollinator Conservation Biocontrol: Beneficial Insects | IPM and Pollinator Conservation University of Minnesota retrieved from: https://ncipmhort.cfans.umn.edu/beneficial-insects

Zagory, E., Hetrick, K. (2016) Introducing 10 Bees and 10 Plants They Love. University of California, Davis
https://arboretum.ucdavis.edu/sites/g/files/dgvnsk1546/files/inline-files/10-bees-10-plants_0.pdf

ABOUT THE AUTHOR :

Patty Puckett Tingler

Patty Puckett Tingler is a certified Skagit County WSU Extension Master Gardener, Class of 2022.

Questions about home gardening or becoming a Master Gardener may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Learn from the experts at the
Country Living Expo
& Modern Homesteading

Saturday, January 27, 2024

Learn More and Register Here >>

These Gardening Topics and More:

• Fruit Tree Pruning & Grafting
• Microclimates in the Garden
• Low Maintenance Gardening
• Roses
• Bee Keeping
• Soil Sampling
• Veggie Gardening
• Growing in High Tunnels, Cold Frames, and Unheated Greenhouses
• Pest Control
• Hop Growing
• Flower Arranging
• Know Your Native Trees
• Introduction into Mason Bees

Seed Saving and Sharing

Open the door to learning about plants in a whole new way.

By Sheri Rylaarsdam, Skagit County WSU Extension Master Gardener

Want to see an adult in an eight-foot-tall sunflower costume? Let your vegetables grow into monsters? Save some cold hard cash? Save an heirloom plant or design a new one?

These are all possibilities once one starts down the road of seed saving. You can begin almost accidentally by not pulling all the radishes in the garden. Several weeks later you’ll notice they have grown six feet tall with multiple branches and hundreds of seedpods. The original radish is an unrecognizable nob at the bottom of the magnificent plant.

Radish plants gone to seed in the author’s garden. © Photo by Sheri Rylaarsdam

Radish seed pods can be collected when they turn brown and look dried out. Interestingly, they are also edible. © Photo by Sheri Rylaarsdam

Now you know getting started is easy enough. So next you may be asking “What other vegetables produce harvestable seeds when left to grow?”

First, always save seeds from open-pollinated plants, not hybrids. Open-pollinated seeds are plants pollinated openly by wind, rain, or flying critters. Heirloom seeds are included in this category, named so because the saved seeds have produced ‘true to type’ plants for fifty years or more. The seeds collected from hybrid plants are sterile because they are a manually-produced cross between two varieties and will not grow true to form.

It is easiest to save inbred or self-pollinated seeds. These are seeds of plants whose pollen is transferred within the same flower or from one flower to the other within the same plant. Peas, beans, lettuce, and most tomatoes are examples of plants with inbred or self-pollinating seeds.

Beet plants grow tall when left to seed. © Photo by Sheri Rylaarsdam

Cobra green pole beans going to seed. © Photo by Sheri Rylaarsdam

Grown from saved open-pollinated seed, this Hungarian Heart tomato is the largest the author has grown. © Photo by Sheri Rylaarsdam

Harvesting Self-Pollinating Seeds
Let beans and peas dry on the plant, then pick the pods to shell. Thresh the pods by hand. The chaff can be winnowed by tossing the pods in the wind and catching the seeds in a basin.

Lettuce seeds send up a seed stalk, ripening two to three weeks after flowering. Harvest daily by shaking the seeds into a paper bag. The lettuce feathers and chaff can then be separated from the seeds using a fine mesh screen.

To save seeds from tomatoes, choose fully ripe tomatoes. Cut across the equator of the tomato and scrape out the gel and seeds. Let the seeds ferment for a couple of days until a black or white mold forms on top. This helps remove any pathogens on the seed surface and also removes the natural germination inhibitor that coats the seed. Strain off the mold and rinse the seeds slowly and carefully. Drain in a fine mesh strainer and dry thoroughly on a saucer. Be sure to label the saved seeds with the name of the variety and the date they were saved. Since the viability of seeds is most affected by fluctuating temperature and moisture levels, it is important to store them in a cool, dry place-ideally in a tightly closed glass jar in the refrigerator.

Harvesting Wind-Pollinated Seeds
Varieties of wind-pollinated plants need to be separated by distance or mature at different times in order not to cross. Wind-pollinated plants include beets, chard, spinach, and corn. Corn pollen is light and can be carried long distances by the wind. A distance of two miles is the recommended isolation distance. A minimum of two hundred plants is needed to have enough genetic diversity.
Harvesting Seeds Pollinated by Bees
Bee-pollinated plants include many ornamental flowers and these vegetable families: Apiaceae (carrots, dill, parsley, cilantro, parsnip, chervil, caraway), Amaryllidaceae (onion, garlic, shallots, scallions, chives, leeks), Brassicaceae (cabbage, broccoli, cauliflower, Brussels sprouts, turnips, kale) and Cucurbitaceae (squash, pumpkins, gourds). If vegetables have the same Latin name they can cross. Avoid cross-pollination by allowing just one type of vegetable from each family to go to seed. For example, if one lets leeks go to seed, do not let onions, garlic, shallots, scallions, or chives go to seed at the same time. The seed-producing vegetable also needs to be isolated from other seed-producing vegetables in its family by one-half mile. Cucurbitaceae are often hand-pollinated. Professional seed savers often use a system of cages to avoid cross-pollination.

Carrots, cabbages, beets, and onions are examples of biennials. These should be left in the ground or stored over the winter and replanted in spring to produce seed in the second year.

Master Gardener Dixie Mitchell repurposes the silca gel packets that come with shipments to keep her seed collection dry until use. © Photo by Ginny Bode

Start with something easy. Choose a variety of beans, peas, lettuce, or tomato that is delicious, grows vigorously, is a good producer, and is resistant to pests and diseases. Once you’ve started saving seeds, collect all the seeds you can. Then you’ll have plenty to plant next year, some to share, some to donate to a seed library or take to a seed swap.

Sharing seeds by donating to a seed library can make it easy for new gardeners to get started. Supplying seeds and information encourages gardeners to be out in nature, eat healthy food, and save money. Seed swaps are an excellent way to get seeds for the garden for the whole next year. Seed swap events usually have music, food, classes, and sometimes adults dressed up like sunflowers!

One can support biodiversity by supporting seed banks, buying from seed companies that increase biodiversity, and contributing to seed libraries and local seed guilds. The U.S. has lost a large percentage of its food plant biodiversity in the last 100 years. By saving seeds, you are doing your part to preserve the genetic diversity which is vital for the future of our food supply.

Seed stewards work to increase, not decrease, biodiversity. By saving and growing open-pollinated varieties of vegetables in the same area for many years and selecting for taste, disease resistance, and productivity, one can develop an improved vegetable. The selected variety will have the characteristics necessary to withstand unfavorable local conditions such as drought or heavy soil.

Seed saving is a gateway to learning about vegetables and flowers in a whole new way, witnessing their whole life cycle and how they interact with other plants. It has led to a new appreciation for nature’s abundance. Through seed sharing, I’ve contributed to altruistic causes that make a difference in the daily lives of people in our community. And I’ve met interesting people that make me smile-such as the fellow seed sharer wearing an eight-foot-tall sunflower costume.

REFERENCES:

Ashworth, Suzanne, 2002, Seed to Seed, Seed Savers Exchange

Gardening for Everyone: Seed Saving/WSU Lewis County Extension/ s3.wp.wsu.edu/uploads/sites/2057/2022/02/Seed-Saving-Handout.pdf

Op-ed: Saving Heirloom Seeds Can Protect Crop Diversity/civil eats/civileats.com/2022/01/27

Community Horticultural Fact Sheet #17/ WSU Jefferson County Extension/ extension.wsu.edu/jefferson/master-gardener-seed-library

Hubbard, Kristina K. January 11, 2019
https://civileats.com/2019/01/11/the-sobering-details-behind-the-latest-seed-monopoly-chart/

Sheri Rylaarsdam

ABOUT THE AUTHOR:

Sheri Rylaarsdam is a Skagit County WSU Extension Master Gardener, Class of 2019. She is an avid seed saver and vegetable grower.

_________

Questions about home gardening or becoming a Master Gardener, may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: https://extension.wsu.edu/skagit/mg/

There’s No Better Place to Make Cider than the Skagit Valley

With the feel of fall in the air some of us just can’t resist the lure of a science project. And there is no better than pressing apples to make apple juice and cider. 

By Ginny Bode, Skagit County WSU Extension Master Gardener

Master Gardeners are an inquisitive bunch and are known for their resourcefulness when it comes to making use of the bounty found in their gardens and orchards. From apples to zucchinis, Master Gardeners have multiple ideas for their preservation and use, all capitalizing on our garden’s harvest because after all, what is better than sitting down to enjoy the food and drink you’ve sourced and prepared?

First off, let’s make sure we are speaking the same language when it comes to apple juice and cider. Many of us think of apple juice as the clear juice that we drank at lunch in school. Apple cider was a rich unfiltered juice we enjoyed in the fall. Those terms are no longer accurate in the marketplace. Though many still use the term ‘cider’ to refer to a non-alcoholic beverage pressed from apples and Websters still defines cider as both fermented and non-alcoholic, in the last 10 years the terminology in the US (both legal and popular) has changed to align with the rest of the world, and cider refers to a fermented drink. For this article, the liquid pressed from apples, both clear and with pulp, is referred to as juice and sometimes sweet cider.

Toby bought his press Correll Cider Press with an electric drive mill more than 20 years ago. He and his friends press 100 gallons of sweet cider each year. © Ginny Bode

While many are content to press their apples to make a pulp-rich juice to drink hot or cold year-round, the juice is also the first step in making ‘hard cider’ or apple cider vinegar. Here we’ll take you through the process of choosing apples and pressing for apple juice and point you to many resources for making fermented apple cider, including that of WSU’s cider research program here in Skagit County.

Choosing The Right Apples For Pressing

Since the settling of America, the northern zones of the US have produced an abundance of apples. Understanding and selecting the right apples for pressing is essential to achieving a delicious and well-balanced flavor.

While many apple varieties can be used and each cider maker has a personal preference, certain types are better suited for cider making than others. Master Gardener Toby Richner has been pressing apples for 40+ years. He believes the key to his success is choosing apples by the season of ripening. Apples ripening early in the season, such as Gravenstein and Pink Lady are tart and considered dessert apples. Ripening later in the season, cider apples such as Kings and Northern Spy produce a sweeter juice because they have been exposed to the sun much longer in the season. Look for apples that possess a good balance of sweetness, acidity, and tannins. He recommends blending apple varieties and possibly adding a ratio of pears to achieve a balanced taste.

These ¾ full 5 gal. buckets of apples pressed into 2 gallons of cider… plus several glasses for ‘test’ tasting. © Ginny Bode

The apples are ground with a mill prior to pressing. © Ginny Bode

At the WSU Mount Vernon NWREC (research center) on Hwy 536 West of Mount Vernon, researchers have compiled a list of 73 cider cultivars-evaluating the apples for their vigor, susceptibility to disease, and quality of the juice for making cider. Though the study is intended for commercial growers the list is helpful when selecting the best apples for your project. https://cider.wsu.edu/ciderweb/

You will need thirty to forty apples to press a gallon of juice. The volume of apples needed to produce many gallons of apples can be cost-prohibitive for the hobbyist unless one has access to an orchard, or can source apples from friends and neighbors. Toby Richner sources the apples needed for the 100 gallons of cider he and his friends produce by relying on years of relationships developed through trading apples for gallons of fresh pressed juice.

Windfall vs. Picked

Many home cider-makers believe windfall apples, those which have fallen due to ripeness and wind, produce the best cider. Scientists say using windfall apples safely depends on how you intend to use the juice-drinking immediately or processing to make hard cider.

If pressing for sweet cider only, WSU Masters student Seth Brawner, working on cider research here at WSU Mount Vernon NWREC, recommends against using windfall apples. He says, that even if pasteurized, the toxin patulin can survive in the juice and cause people to get sick. To avoid this, only use picked apples in sweet cider. Seth goes on to say, “If using your pressed juice to make hard cider, windfall apples can be used because fermentation is considered a “kill step” because the alcohol produced during this process will destroy patulin and eliminate pathogens in the cider.”

When using windfall apples, take extra vigilance. Always cut away any areas bit by deer or other critters, dispose of any rotten or wormy areas, and wash thoroughly in a chlorine bath. Poor-quality fruit will diminish the taste of your cider. Michigan State University Extension has produced an excellent food safety guide referenced below.

Master Gardener Toby Richner has been making sweet cider for more than 40 years. Beyond enjoying great cider year around, he enjoys the community they’ve built trading apples for fresh pressed cider. © Ginny Bode

The press bears down on the milled apples to release the juice which flows into food grade containers-in this case, stainless steel buckets. © Ginny Bode

Equipment Needed for Homemade Sweet Cider

Along with apples, to embark on your home cider making journey you’ll need:

–      Cider Press– to efficiently extract the juice from the apples.
–     Food processor or grinder– to break down the apples before pressing.
–     Large food-grade vessel- a 20-30 gal container for mixing juice before bottling
–     2-3 gal. food-grade buckets for ‘catching’ the juice as pressed
–     Jugs and/or bottles – for storage

There are various methods for pressing apples available, ranging from simple hand-pressing techniques to using a specialized cider press. The cider press is the most efficient method of crushing the apples and releasing their juice while leaving behind the pulp and seeds. Home presses are available in many sizes and styles ranging from $100 to over $2000.

Preparing the Apples For Pressing
Start by washing the apples thoroughly to eliminate dirt or debris. Inspect each apple for any signs of damage or rot. Remove any spoiled fruits to ensure the quality of your cider. After cleaning, quarter the apples into small pieces, then, keeping the seeds and stems, grind them with a food processor or mill.
Pressing The Apples, Extracting and Storing the Juice
Now the fun begins-pressing the ground apples to obtain their flavorful juice. Capture the juice as it flows from the press. Strain the juice through a fine mesh, sieve, or cheesecloth to remove any remaining solids that may have slipped through the press. Transfer to clean jugs with airtight lids, leaving headspace for expansion when freezing. If you don’t have room in your freezer, the juice can be preserved through the canning process. Refrigerate if you plan to drink right away.

Commercially sold juices and sweet ciders are usually pasteurized for food safety purposes. Many home juice and cider-makers believe unpasteurized juice retains more flavor, vitamins, minerals, and antioxidants. Though pasteurization doesn’t completely eliminate the risk of foodborne illness, it does reduce it.

The Fermentation Process: Taking the Next Step to Cider

When the apples have been pressed and the juice made, the real science project begins – the fermentation process. This crucial step is what turns pressed apple juice into flavorful and aromatic cider.

Adam Coy started his cider making adventure in his garage. He is now the cider maker for Farmstrong Brewing’s Ragged & Right Project in Mount Vernon. Coy says “cider making is fairly simple when you break it down. You need juice with a fair amount of natural sugar, a clean vessel to put it in, and a little yeast to start it all off. It should be kept cool, but not overly cold/freezing. Then it’s just a matter of time to let the yeast do its work. With just a few basic tools, anyone can make cider at home.”

He started home brewing, referring to it as an adult science project.  And like many cider makers, he bought the juice from a local orchard and found the basic supplies at the local brewing shop: a 6 gal. carboy (water cooler style jug); water lock and stopper; a hydrometer; a siphon and a thermometer.

Master Gardener Bob Bryan does the process from start to finish using apples from his orchard to create the cider. Filling the 6 gal. carboy with fresh pressed juice, he then lets the sediments settle out overnight before getting started. He uses sulfur dioxide (SO₂) to kill the microorganisms in the fresh-pressed juice. Then within 12-24 hours adds his preferred strain of yeast. The yeast consumes the natural sugars and converts them to alcohol. Both Bryan and Coy equate cider making to wine-making and enjoy the process of constantly measuring and maintaining proper temperature and oxygen levels to ensure successful fermentation.

The exact steps to the fermentation process can be found at https://cidersage.com/tutorials/hard-cider-making-tutorial/ or in WSU’s publication Hard Cider Production and Orchard Management in the Pacific Northwest. (https://pubs.extension.wsu.edu/hard-cider-production-and-orchard-management-in-the-pacific-northwest/)

Once a prominent part of American culture, cider making in the US is experiencing a resurgence in consumer demand with a 30-fold increase in the number of cideries. Skagit Valley is home to one of the main US apple research programs at WSU Mount Vernon NWREC and is an excellent place to start your cider making journey.

RESOURCES AND FURTHER LEARNING:

If you are highly interested in furthering your hard cider making expertise, the Cider Institute also offers online and in-person courses, including one offered in Mount Vernon in December of 2024. https://www.ciderinstitute.com/courses#Courses

https://cider.wsu.edu/  Washington State University

https://hardcider.cals.cornell.edu/ Cornell University

A brief history of cider in the US: https://cider.wsu.edu/history-of-cider/

https://www.agbizcenter.org/resources/all-things-cider/

https://www.nwcider.com/ Northwest Cider Association (NWCA) is a regional group of cider makers and orchardists from the PNW and British Columbia.

https://www.canr.msu.edu/news/its_cider_time
Sprague, S. and Venema, C.; Michigan State University Extension – November 22, 2022

https://www.canr.msu.edu/news/pasteurized_or_unpasteurized_juice_whats_the_difference

Nichols, J., Michigan State University Extension – September 12, 2014

Ginny Bode

ABOUT THE AUTHOR:

Ginny Bode is Skagit County WSU Extension Master Gardener and Co-editor of the Ask a Master Gardener Blog.

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Questions about home gardening or becoming a Master Gardener, may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: https://extension.wsu.edu/skagit/mg/

Mock Orange © Joan Stamm

Tallamy’s “Homegrown National Park”

A grass-roots movement of individual homeowners and gardeners growing native plants to restore habitats for biodiversity

By Joan D. Stamm, Skagit County WSU Extension Master Gardener

Joan D. Stamm

For the last thirty years, I’ve been enamored with native plants from Asia-peony, azalea, camellia, hydrangea, wisteria, kerria, bamboo, and chrysanthemum to name a few. I’ve grown or tried to grow all of them in my garden to use in ikebana (Japanese flower arranging). But more recently, after reading Douglas Tallamy’s Nature’s Best Hope: A New Approach to Conservation that Starts in Your Yard-a book that would irrevocably change my view of gardening-I’ve turned to NW natives.

Tallamy, a professor of entomology and wildlife ecology at the University of Delaware, urges us to ditch our lawns and ornamentals-our “introduced” species-and grow native plants instead. Conservation zones and national parks are not enough. Although these areas are meant to preserve native habitat for native plant, animal, and insect species, they are a small fraction of our overall landmass. “Turfgrass has replaced diverse native plant communities in more than 40 million acres, and we are adding 500 square miles of lawn to the United States each year,” says Tallamy, quoting from Elizabeth Kolbert’s Pulitzer prize-winning book The Sixth Extinction.

Monkey flower (Erythranthe lewisii) © Joan Stamm

Douglas aster (Symphyotrichum subspicatum © Joan Stamm

Then there’s the question of how we use our water resources as we see drought spreading across the Western U.S. and other parts of the world. “In the U.S., lawn irrigation consumes on average more than eight billion gallons of water daily”; and, according to the Environmental Protection Agency, “40-60 percent of fertilizers applied to lawns end up in surface and groundwater.” In addition, we have pesticides that further contaminate our water and routinely kill pollinators. “Forty percent of these chemicals are banned in other countries because they are carcinogens.”

Tallamy goes on to say that 3 billion birds have already disappeared since 1970 due to loss of food and habitat. “A staggering loss that suggests the very fabric of North America’s ecosystem is unraveling.” Birds are like the “canary in the coal mine” of climate change. When our birds start disappearing, we humans are in trouble. “In North America, 432 species of birds are at risk of extinction.”

Tallamy’s mission is to begin a grass-roots movement of individual homeowners and gardeners growing native plants to create corridors of natural landscape. His argument is simple: instead of millions of acres of lawns, golf courses, and urban/suburban “deadscapes,” we need native habitats to restore biodiversity. “It is insects that run the world,” he says, “and it takes certain native plants to support healthy populations of those insects.” In short, we need what Tallamy calls a “Homegrown National Park”: a return to the natural world with a balanced ecosystem.

Blanket flower (Gaillardia aristata) © Joan Stamm

Oregon grape (Mahonia aquifolium) © Joan Stamm

Tallamy suggests three action steps:

• Reduce our lawns (which will curb water, fertilizer, and pesticide use).
• Plant more natives (which will bring in beneficial habitat, food for native pollinators, and reduce water use).
• Remove invasives (because they crowd out and replace vital natives).

After reading Tallamy’s book I woke up to how “me” centered my gardening had been: growing plants that pleased only me, without the slightest thought to our many birds, butterflies, bees, and other creatures struggling to survive. For example, I found no reference that listed my beloved peonies as pollinator-friendly plants in the Pacific Northwest. Hydrangea? No. Kerria and wisteria? Not really. Camellia? Maybe. Cisco Morris suggests that Anna’s hummingbirds enjoy ‘Yuletide,’ since it is red, single-petaled, and blooms in winter, but I have no personal observation to report. More importantly, “80% of a hummingbird’s diet is insects and spiders.”

Backyard before conversion to natural landscape © Joan Stamm

Backyard after conversion to native corridor landscape © Joan Stamm

“And what about cultivars?”, many ask Tallamy. What about those many stunning and alluring flower and leaf varieties produced through selective breeding that we find at most of our nurseries? According to research done by Tallamy and other scientists, whether a cultivar retains any benefit to pollinators depends on what got modified. He advises avoiding plants where the leaf color has been changed from green to brown, purple or red (because insects like chlorophyll), and best to avoid flowers that went from single-petaled to multi-petaled (bees can’t get inside), or plants that have been made sterile. On the other hand, a woody plant made shorter is relatively okay. In sum, no size fits all. A quick tutorial can be found on the Grow Native website https://grownative.org/learn/natives-cultivars-and-nativars/ or in the Q&A in Tallamy’s book.

Two last bits of important advice for encouraging beneficial insect/caterpillar production to feed those hungry birds is to “leave the leaves” and turn off outdoor nighttime lighting. Cleaning up leaf litter destroys important habitat for invertebrates. “Our fall cleanup,” says Tallamy, “is particularly hard on bee populations; the perennials we are anxious to cut back after they have bloomed are where pithy stem nesters are hoping to spend the winter.” As for outdoor lighting, harsh LEDs destroy moths and other nighttime insects that are crucial to the ecosystem. Either turn off outdoor lighting at night, invest in motion detectors, or if you must have light, use “yellow bug lights.”

Ikebana arrangement with Madrone, Mahonia nervosa, and yarrow © Joan Stamm

As for my ikebana arrangements? Well, my strong attachment to certain Japanese flowers won’t depart easily, and I’m not saying that I won’t grow a few peonies anymore, but I know too much now to return to my old habits. I’ve started using native plants and flowers in my flower designs.

If you do decide to join the Homegrown National Park movement and go “native,” get registered here: https://www.homegrownnationalpark.org/ . Collectively, I believe we can make a difference and help restore our earth’s ecosystem. With so many dire statistics, there’s no time to lose.

REFERENCES:

• Fitzpatrick, John and Marra, Peter. September 2019. “Decline of the North American Avifauna.” Science.
• Kolbert, Elizabeth. 2014. “The Sixth Extinction: An Unnatural History”. New York: Henry Holt & Co.
• Morris, Ciscoe. October 11, 2017. “Keep your hummingbirds happy…” The Seattle Times.
• Tallamy, Douglas W. 2019. “Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard”. Portland: Timber Press.

ABOUT THE AUTHOR:

Joan D. Stamm has recently completed the requirements as a Skagit County WSU Extension Master Gardener (EMG) Class of 2023. She is the author of several books, most recently The Language of Flowers in the Time of COVID: Finding Solace in Zen, Nature and Ikebana.

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Questions about home gardening or becoming a Master Gardener, may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: https://extension.wsu.edu/skagit/mg/

Discover the Skagit Valley Display Gardens Open House

Discover the Discovery Garden, NW Fruit Garden, and the Salal Native Plant Garden

By Janine Wentworth, Skagit County WSU Extension Master Gardener

June is the beginning of summer blooming, fruit and vegetable growth and early harvests.

Enjoy the summer gardens of Skagit Valley at the Discover the Display Gardens Open House. Skagit Valley is home to 8 acres of display gardens operated by volunteers as a learning resource for the public.

Discover the Display Gardens
Open House

June 24, 2023 · 10 am – 2 pm

Free Admission

• Skagit County WSU Extension Master Gardener Discovery Garden
• Western Washington Fruit Research Foundation
• Salal Native Plant Garden

All three are nestled together in the green fields of the WSU Northwestern Washington Research and Extension Center west of Mount Vernon on HWY 536 (Memorial Hwy.)

While all three of these gardens are open to the public daily, the Annual Open House is focused on educating and inspiring visitors interested in many specific areas of interest, including pollination, water-wise gardening, native plants and raising fruits and vegetables in the Skagit area.

The Discovery Garden
Designed to support Skagit home gardeners by promoting science-based gardening practices, Skagit area WSU Extension Master Gardeners have created 30 garden rooms within the garden, featuring hundreds of plants chosen to flourish in Skagit Valley. Come and spend time with the volunteers who maintain the gardens and learn more about what they grow.

In addition to tours of the garden rooms, Master Gardeners will be on hand offering activities for all ages including:

• Free garden tool sharpening
• Solutions to plant problems
• Plant identification– to help you know what you have
• Expert advice on weed identification and management

While at the Discovery Garden, visit the small fruits garden and learn more about food you can grow in your own back yard. Photo © Nancy Crowell Photography

Visit the learning station near the pond in the Naturescape Garden. There you will see Koi fish and learn about pond maintenance and construction as well as drip irrigation.

Bring a blanket and picnic lunch and enjoy the day at the Discovery Garden. Photo © Nancy Crowell Photography

Learn about effective gardening at the 8 education stations located throughout the garden area. Master Gardeners will offer instruction on topics such as:

• Developing healthy soil
• Composting
• Pollinator support
• Fruit tree pruning and thinning
• Gardening with native plants
• Weed identification: Match examples of common weeds with their names so you can learn how to identify them and control them
• Clean water and water conservation: Visit the learning station near the pond in the Naturescape Garden. There you will see Koi fish and learn about pond maintenance and construction as well as drip irrigation

Pollinators: Learn about plants that support pollinators from Master Gardeners who plant and care for the pollinator gardens and the pollinators that live in the garden. The pollinator station at the Open House will teach ways to help native bees and other pollinators thrive in home and community landscapes because pollination is an essential survival function.

Local Food: The Skagit County WSU Extension Master Gardeners offer extensive resources for local gardeners. During the Open House, Master Gardeners will be giving talks on healthy soils, growing your own vegetables, and weed identification and eradication. The Grow Your Own Food page at https://skagitmg.org/home/resources/food/ is also an excellent resource for gardeners getting started.

While at the Discovery Garden, visit the Vegetable, Small Fruits, and Doc’s Arbor garden rooms for ideas and examples of food-producing plants that grow well in the Skagit County area.

Educators from the Xerex Society will be at the Open House demonstrating techniques for making your garden pollinator friendly

Learn smarter vegetable gardening tips from the Master Gardeners who have research and tested a variety techniques that face gardeners in the North Puget Sound area.

Throughout the growing season, garden waste is sorted, chopped, and chipped– the browns and greens are com­bined and turned, giving us nutrient-rich compost in a few months.

Composting: Curious about how to get started composting? Composting reduces waste and provides an inexpensive treatment for home gardens and landscapes. Healthy soil is essential to have healthy plants. Come talk to our soil experts and learn about your soil and what you can do to improve it.

Growing the Discovery Gardens since 1996
In 1994, the Skagit County WSU Extension Master Gardeners had a vision for a garden that would demonstrate best practices for gardening in the Skagit area. After two years of planning, the garden’s first structure of trees and fences was placed in the fall of 1996. Over the following two years, many committed WSU Extension Master Gardeners, along with the help of the community, planted the gardens.

The WSU Master Gardener Program addresses important sociologic and environmental issues by teaching research-based horticulture information. We want people to have important skills and abilities that help mitigate challenges and to understand that everyone has a role to play in creating and sustaining healthy and resilient communities.

Salal Native Plant Garden
The second garden participating in the Tri-Garden Open House is the Salal Native Plant Garden. Bordering the Discovery Garden to the south, the Salal Native Plant Garden is entered by walking through the Discovery Garden following the paths to the south. This labor of love and concern for native plants is manifested in an extensive and charming display garden.

Created twenty-five years ago as a collaborative effort between volunteers of the Salal Chapter of the Washington Native Plant Society and the Washington State University Agriculture Extension Agency at Mount Vernon (WSU), the Native Plant Garden is now a half-acre oasis that holds the seeds for the future of native plants in the lower Skagit Valley. The garden is a terrific resource for homeowners who want to learn how to incorporate more native plants into their landscaping.

Western Washington Fruit Research Foundation (NW Fruit)
The third garden on display is the fruit garden known as the Western Washington Fruit Research Foundation (or NWFruit.org). Here volunteers will answer questions about fruit trees. The 6-acre garden was designed and constructed by volunteers of the foundation and contains large informational signs and handouts based on the research conducted by Washington State University.

During the Open House volunteers will be on hand to explain examples of netting for bird control, a Tatura trellis, and answer questions about the expansive espalier display.

The fruit garden contains a large collection of fruiting plants with many unique varieties, including a collection of 17 variations of Gravenstein apples, a collection of antique apples from all over the world, and unusual fruits such as medlar and blue honeyberry. Located on the west side of the Discovery Garden the fruit garden is open to the public seven days a week from dawn to dusk.

Please join us for the Open House festivities on June 24, 2023 from 10 am – 2 pm. You are welcome to bring a blanket and picnic lunch and enjoy the day with family and friends.

The gardens are open and free to the public throughout the year, 7 days a week from dawn to dusk. Visit the gardens throughout the seasons to view the seasonal changes. Signage in each garden identifies plants and makes for interesting and educational self-guided tours.

RESOURCES:

• Discover the Display Gardens website
• Learn about Master Gardener program priorities: https://mastergardener.wsu.edu/priorities/
• Interested in Composting and Vermacomposting? See our recent blog article at: https://skagitmg.org/vermicomposting/
• Get started growing your own food: https://skagitmg.org/home/resources/food/

ABOUT THE AUTHOR:

Janine Wentworth became a master gardener in 2018. She and Kay Torrance are co-chairs of the Discovery Garden Open House.

Questions about home gardening or becoming a master gardener may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Italian Arum: Beautiful, Poisonous and Invasive

Don’t Be Deceived by This Beautiful Ground Cover

By Valerie Rose, Skagit County WSU Extension Master Gardener

What a deceptive plant! First of all, Italian Arum (Arum italicum) is not strictly Italian. Native to Asia, Europe, and North Africa, some botanical resources say it’s also found in southern Europe. Other common names include Cuckoo’s Pint, Italian Lily, and Orange Candle Flower. While many of these names point to Italy as the source of this problematic plant, its roots appear much more widespread.

Flowers (April-June) are a yellowish unpleasant-smelling, fingerlike spadix with a pale hood, or spathe. © Washington State Noxious Weed Control Board

Italian Arum is also deceptively attractive. The bright orange berries brought color to an otherwise nondescript area of the yard, so I let it grow. Now I wish it had never found my address. It now appears in most of my garden beds, even in the lawn, where it has made friends with the equally intrusive buttercups. They’re conspiring to take over the whole yard, and I struggle to keep them at bay. We gardeners are seriously outnumbered.

My yard is not alone. In addition to being a pest in Skagit County, the plants are found between 10 and 100 acres in Whatcom, King, Skamania, and Clark Counties. More acres have been infested since that figure was published in 2018 by the Washington State Department of Agriculture (WSDA.) Italian Arum is also invading forest understories and wetlands, forming dense infestations, and crowding out native plants.

Because it is so invasive and poisonous to humans and animals, the WSDA classifies it as a Class C Noxious Weed. The WSDA describes Class C Noxious weeds as those “… already widespread in Washington. In some cases, counties may require property owners to control Class C weeds, but more often counties simply try to educate residents about why controlling them is a good idea.”

What about Class A and B weeds? The WSDA describes these categories:

“Class A Noxious Weeds are non-native species whose distribution in Washington state is still limited. Eradicating existing infestations and preventing new infestations are the highest priority. Eradication of all Class A plants is required by law.”

Arrowhead-shaped leaves can be all green or have cream-colored or silver-gray veins, purple splotches, or speckles. © Washington State Noxious Weed Control Board

Thick underground tubers store much of the plant’s energy and water underground, which is why the tops regrow so easily when cut or mowed. © Washington State Noxious Weed Control Board

Class B noxious weeds are nonnative species whose distribution is limited to portions of Washington state but may be widespread in other parts. Class B noxious weeds are designated for mandatory control in regions where they are not yet widespread.”

Like many invasive plants, Italian Arum likely escaped from someone’s garden. Originally planted as an ornamental ground cover, it certainly does cover ground. The first documented site in Washington state was on San Juan Island in 2002. This (ob)noxious weed is currently invading the west coast of the US and lower mainland British Columbia and across the mid-Atlantic states.

Not only is this plant invasive, but it also contains calcium oxalates, poisonous to humans and animals. According to the North Carolina Extension Gardener Toolbox, the calcium oxalates, if ingested “…will cause throat and tongue swelling that will result in difficulty breathing or possible death.” Simple skin contact can cause mild to severe irritation. Always protect your skin when attempting to remove Italian Arum.

Unfortunately, the plant tolerates most soil types, is drought tolerant once established, and thrives in partial shade to full sun. Like many undesired plants, it has more than one reproductive strategy. It grows from both tubers and berries, reaching 12 – 18 inches tall. The arrow-shaped leaves appear in early autumn, with hood-like flowers blooming in April and May: their acrid odor attracts flies as pollinators. When the foliage withers, stalks emerge, eventually covered in clusters of berries. The plump berries are initially green, changing to a vivid orange-red. This dramatic show continues through August, giving birds plenty of time to snack on the berries, and then deposit the seeds around your yard and beyond – conveniently coated with fertilizer.

Once established, Italian Arum is maddeningly difficult to get rid of. According to the North Carolina Extension Gardener Plant Toolbox, “There are no effective ways to control the plant, and it is unresponsive to herbicides. Manual removal is difficult. If removed, all parts of the plant should be placed in the trash and not your compost bin.”

Spreading by both roots and seeds, Italian arum rapidly forms colonies. © Washington State Noxious Weed Control Board

Spread by both tubers and seeds, Italian arum multiplies quickly, creating new plants. © Washington State Noxious Weed Control Board

2-acre infestation on Lopez Island actually worsened after it was repeatedly mowed, dug, torched (in winter), and then covered with a heavy tarp. © Washington State Noxious Weed Control Board

An Oregon State University Extension’s Ask An Expert webpage offers this: “Some suggest success by pouring boiling water on the plant’s roots. If using vinegar, a 20% vinegar solution is best. This type of vinegar, sometimes called horticultural vinegar, can be found at garden centers, farm stores, or online. Wear gloves and protective clothing to protect your skin from possible irritation. Follow-up work will be required to control any plants that develop from missed plant parts.” I will explore this strategy, as my annual ritual of carefully digging the roots and bulbs has not eliminated this invasion.

Don’t let the pretty leaves or colorful berries fool you into letting Italian Arum take root in your yard. And tell your friends and neighbors not to allow Italian Arum to charm its way into their gardens.

RESOURCES:

• Washington State Noxious Weed Control Board
  https://www.nwcb.wa.gov/weeds/italian-arum
• https://www.skagitcounty.net/Departments/NoxiousWeeds/weedlist.htm
• North Carolina Extension Gardener/Plant Toolbox
  https://plants.ces.ncsu.edu/plants/arum-italicum/
• https://cms.agr.wa.gov/getmedia/8e970f5e-72b0-4dcc-99d5-a1c9aad48ef7/ItalianArum.pdf
  Italian Arum Distribution, 2018, Washington State Department of Agriculture
• Clackamas County Weed Wise
  https://weedwise.conservationdistrict.org/arit-2
• Oregon State University Extension, Ask An Expert
  https://extension.oregonstate.edu/ask-expert/featured/how-can-i-organically-get-rid-italian-arum
• https://www.co.cowlitz.wa.us/DocumentCenter/View/13974/Italian-Arum

Valerie Rose

ABOUT THE AUTHOR:

Valerie Rose became a Master Gardener in 2009. A former journalist, she enjoys playing with words, and plants other than Italian Arum.

Questions about home gardening or becoming a Master Gardener may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Master Gardeners Visit the UW Botanic Gardens

Hallmarks of the Master Gardener Program: Shared Love of Plants and Learning

By Kay Torrance, Skagit County WSU Extension Master Gardener

What would draw a group predominately made up of WSU Cougs to venture into the heart of UW Huskies territory? It wasn’t a sporting event, but plants and a visit to the University of Washington’s extensive botanic resources: the Washington Park Arboretum, the Elisabeth C. Miller Library, and the new state-of-the-art UW Biology Greenhouse.

Regardless of the school colors they fly, a common characteristic among Master Gardeners is a shared love of plants and an ongoing commitment to learning. So it follows that when the opportunity to visit the extensive plant collections housed at the UW arose, it was not a surprise when registration filled quickly for the early March visit.

The tour’s first stop was the 230-acre UW Botanic Gardens Washington Park Arboretum. Noted for its meandering footpaths, the arboretum gardens feature collections of oaks, maples, camellias, and accompanying understory. During the early March visit the Joseph A. Witt Winter Garden was still in full splendor. The subtle colors of flowering hellebores and witch hazel were striking against a backdrop of textured bark from birches, maples, and twig dogwoods. Rhododendrons and camellias added a splash of dark green. The arboretum is open every day from dawn to dusk, free of charge.

Photo: Bobbi Lemme

Photo: Kay Torrance

Photo: Jessimine Tuttle

Elisabeth C. Miller Library at the botanic gardens was the second stop on the trip. Here, Brian Thompson, Library Manager and Curator of Horticultural Literature guided the Master Gardener group through the library’s extensive resources.

The Elisabeth C. Miller Library features Pacific Northwest Connections, a collection dedicated to plants and gardening in our unique climate. The library also features collections focused on geographic areas from around the world including New Zealand, Australia, China, Japan, South Africa, Chile, and the Mediterranean. The library’s collection of over 16,000 books includes rare and historical books, botanical drawings, nursery catalogs, and over 200 current periodicals and back issues.

The walls of the Elisabeth C. Miller Library are devoted to rotating art exhibits. Outside of the library is a tranquil courtyard adorned with plants from all over the world and furnished with scattered chairs and tables, a perfect place to read and contemplate gardening. The library is open to the public six days a week.

Photo: Diane Bowman

Photo: Charlene Day

Photo: Kay Torrance

The final stop of the Master Gardener’s bus tour was the new UW Biology Greenhouse at the Life Sciences Building. The 20,000-square-foot greenhouse first opened to the public in 2022. The state-of-the-art building is home to over 4,000 species of plants and growing! Master Gardeners were guided through four-themed garden rooms: Warm Tropics, Tree of Life, Cool Tropics, and Desert. On the cool, early March day, it was wonderful to take our coats off and step into a desert and then into a jungle.

Seattle botanical artist Crystal Shin was our docent for the Desert Room where plants are grouped by continent of origin. As the primary botanical illustrator for the University of Washington Herbarium book Flora of the Pacific Northwest (2^nd Ed.) Crystal has spent extensive time studying and illustrating plants in the UW collection. The Desert Room holds an impressive collection of North American cacti and a table of euphorbias from Africa. Prized specimens include a Welwitschia from Namibia, and a cherry blossom pink Adenium, and examples of Gasteria. Many of the plants demonstrate convergent evolution where plants adaptation mechanisms resulted in similar appearance despite separate evolutionary lineages.

Alex Lowe, a graduate student advisor, led the Master Gardeners through the Tree of Life room where plants are displayed in their evolutionary order of appearance starting with algae and mosses and then moving through Selaginellas, lycopods, ferns, gymnosperms, and finally angiosperms. The room includes examples of plants with economic importance such as bananas, pineapples, peppers, vanilla orchids, tobacco, and cotton.

Photo: Kay Torrance

Photo: Kelly Maupin

Photo: Kay Torrance

A large group of Skagit Master Gardeners received continuing education credits for tour and learning experience to the University of Washington Botanic Gardens. Photo: Nancy Crowell

Next, we walked into the lush Warm Tropics room with Hannah McConnell, Ph.D. candidate, and were surrounded by palms, gingers, water plants, and orchids including a huge Grammatophyllum specimen.

The final garden room was the Cool Tropics Room. Here, Nile Kurashige, greenhouse plant technician introduced the group to tropical plants native to higher altitudes or latitudes. Highlights of the room included more orchids, carnivorous plants, Hoyas, and a huge Angiopteris fern reaching toward the ceiling.

In addition to the four garden rooms, the greenhouse complex has five climate-controlled rooms for education and research purposes and classroom space for courses in plant biology. The Biology Greenhouse supports UW students in subjects ranging from plant ecology to landscape architecture and anthropology. The greenhouse is open to the public for browsing on non-holiday Thursdays, and on the 2^nd and 4^th Saturdays of each month from 12 – 4 pm.

As the final tour wrapped up and we boarded our bus to head home, we were grateful for the learning opportunity, and realized how fortunate we are to have these world-class botanical resources open to the public and so close to home.

REFERENCES:

More info can be found at:

https://www.biology.washington.edu/facilities/greenhouse

Instagram at https://www.instagram.com/uwbiogreenhouse/.

https://www.seattletimes.com/seattle-news/inside-uws-new-greenhouse-and-a-closeup-look-at-its-rare-and-exotic-plants/

New home gives biology department’s plant collection room to grow

Leo Hitchcock and Arthur Cronquist Ed. 2018. Flora of the Pacific Northwest. 2^nd Ed. Seattle, WA, University of Washington Press

ABOUT THE AUTHOR:

Kay Torrance is a Skagit County WSU Extension Master Gardener. She is Coordinator of the Naturescape Garden at the Discovery Garden on State Route 536 west of Mount Vernon.

Questions about home gardening or becoming a Master Gardener, may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Tree Squirrels of the Pacific Northwest

Gardener’s Friend or Foe?

By Kathy Wolfe, Skagit County WSU Extension Master Gardener

Squirrel ˈskwə-rəl
noun:

1. a: Lively, adorable, cavorting, wide-eyed, bush-tailed acrobat whose antics and gyrations are a joy to watch.b: Destroyer of flower beds and home irrigation lines, raider of bird feeders, disease-carrying rodent full of fleas and ticks.

Here in lies the ambiguity of the squirrel. At times they can be the most entertaining creatures in our yard and at other times they can be very destructive to our landscapes, wildlife, and home structures.

Identification:
Washington has four native species of tree squirrels.

Kathy Wolfe

The Douglas squirrel (Tamiasciurus douglasii) measures 10 – 14 inches in length, including its tail, with a reddish or brownish gray back and an orange or yellowish belly. Douglas squirrels are usually found in cedar, pine, and fir forests in western Washington and the Cascade Mountains.

The Red squirrel (Tamiasciurus hudsonicus) is approximately the same size as the Douglas squirrel and lives in semi-open woods and coniferous forests in northeast Washington. Their rusty-red coat and white or grayish-white bellies help identify them.

The Western Gray squirrel (Sciurus griseus) is a larger animal measuring between 18 – 24 inches long. It has a gray upper body and creamy undercoat featuring a long, bushy tail with white edges. Western Gray squirrels are found in western and central Washington in low-elevation oak and conifer woods.

The Northern Flying squirrel (Glaucomys sabrinus) is smaller than the others, measuring 10 – 12 inches in total length. It can have a dark gray or brown body with a creamy underbelly. The large, dark eyes are another key to identifying it, as is the wide and flat tail. Seldom seen, they glide through the trees at night.

In addition to our native squirrels, the Eastern Gray squirrel and Eastern Fox squirrel were introduced in Washington in the early 1900s. They are the most common tree squirrels in urban areas and are often spotted in parks, campuses, and residential areas. The Eastern Gray squirrel, gray with a reddish wash in summer with a whitish belly, is about 20 inches long, half of which is its prominent, bushy tail. The Eastern Fox squirrel is approximately 22 inches long which includes a large tail measuring 9 – 10 inches. Its coloration is usually dark gray with a reddish cast and orange to deep buff underpinning. The fur color of both introduced squirrels can vary widely and sometimes they can be almost entirely black. 

Squirrels enjoy eating acorns, seeds, tree buds and berries as well as plants and twigs.” Photo by Nancy Crowell / WSU Skagit County Extension Master Gardener

Squirrels are vulnerable to hawks, owls, dogs, coyotes and bobcats. Watch your back, little fellow! Photo by Nancy Crowell / WSU Skagit County Extension Master Gardener

Eating habits:
Squirrels can be seen eating acorns, seeds, tree buds, and berries as well as plant material and twigs. Occasionally they will eat parts of a bird’s nest– the eggs, or baby chicks. Insects and fungi are also a part of their diet. They store their food in hollow stumps, abandoned burrows, and any hidey-hole they can find – including exhaust pipes, under flower pots and in unused cars. In the fall when Douglas squirrels and Red squirrels are harvesting and storing food for winter, you may see debris under oak, maple, nut trees, and conifers which indicates that the animals have been breaking off seed and nut clusters and dropping them to the ground where they harvest them for a meal or store for later use. You might find a pile of cone scales under a tree where squirrels have harvested the seeds of the cone.
Nesting, mating, and lifestyle habits:
Hollow cavities are also used for nesting. Leaves, twigs, shredded bark, moss, insulation and other soft materials are used to structure their nests. When hollow cavities are not available, spherical or cup-shaped nests are built in trees, bird nesting boxes or even attics. In cold weather, red squirrels may nest underground, often near where they have stored their food. Urban squirrels generally nest in buildings or other structures.

Mating occurs in early winter to late spring, with one litter of two to four babies produced in March through June. Some species may have a second litter in August or September.

Although squirrels are relatively safe when up in trees, they are vulnerable on the ground to hawks, owls, cats, dogs, coyotes, and bobcats. Vehicles, disease, and starvation are also killers. Squirrels can live for three to five years, but most die within their first year.

Squirrels are most active from dawn to dusk. They do not hibernate in winter but remain in their nests if the weather is stormy or cold.

If you watch squirrels running up and down a tree, you might notice their speed. Their double-jointed hind legs propel them forward quickly. They also use their very sharp front claws to grip and climb.

Listen to their distinctive call. A Red or Douglas squirrel whose territory is being trespassed may produce a rapid tsik tsik tsik. The Eastern gray squirrel flicks its tail while making a que, que, que, que sound.

Squirrels use their double jointed hind legs to propel them forward and sharp claws to grip and climb. Photo by Nancy Crowell / WSU Skagit County Extension Master Gardener

Managing Human/Squirrel Interaction:

Tree squirrels can be destructive to bird feeders and bulb plantings among other things. Should a squirrel decide to take up residence in your attic or down your chimney, you won’t be pleased. To limit this, look around your buildings and eliminate access through dryer and roof vents, rotten siding or boards. Keep tree and shrub branches pruned away from buildings and roofs to eliminate access to these areas. Barriers around fruit trees, bulbs, and tree bark can be used to deter these determined creatures. Check the Internet for examples of designs that might work for you. You may also want to try commercial deterrent sprays.

To prevent potential conflicts, you should never feed squirrels. Use squirrel-resistant bird feeders and check bird nesting boxes for squirrel nesting sites.

If a squirrel gets adapted to hand-feeding (as cute as it is), it may lose the fear of humans and become aggressive. If a person is bitten or scratched by a tree squirrel, immediately scrub the wound with soap and water and flush liberally with tap water.

How would you describe the squirrels in your yard? Cute and amusing entertainers or destructive, vermin-infested rodents? Perhaps a little bit of both?

REFERENCES:

“The Pacific NW Squirrel, Cute Furry Creatures or Pesky Rodent”, Get Smart Rat Solutions. https://getsmartratsolutions.com/the-pacific-nw-squirrel-cute-furry-creatures-or-pesky-rodent/

“Living with wildlife: Tree squirrels”, Washington Department of Fish and Wildlife. https://wdfw.wa.gov/species-habitats/living/species-facts/tree-squirrels

 Living with Wildlife in the Pacific Northwest, Russell Link, University of Washington Press, 2004.

ABOUT THE AUTHOR:

Kathy Wolfe has been Skagit County WSU Extension Master Gardener since 2002. She is Co-coordinator of the vegetable garden at the Discovery Garden on State Route 536 west of Mount Vernon.

Questions about home gardening or becoming a Master Gardener, may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Midnight Marauders

Managing Those Pesky Slugs and Snails

By Diana Wisen, Skagit County WSU Extension Master Gardener

Pacific Northwest gardeners probably spend more time discussing slug damage than almost any other garden problem. Slugs require moisture in the soil and vegetation, both of which are abundant in our area.
During cold or dry weather, they can move down into the soil. Adult slugs and snails live through the winter in this region, seeking shelter underground. In dry or hot weather, they can borrow down as much as 6 feet to find cool dampness. They can seal themselves off with a parchment-like membrane for protection from the elements. They are Gastropods from the Greek meaning “belly foot”.

Most of the slugs and snails you see in your yard are non-native, invasive varieties. The native Banana slug, a good guy, is found mostly in wooded areas, not suburban landscapes, and tends to eat only decaying matter. There are many species of non-native slugs that attack your plants.

Diana Wisen

Two of the most destructive are the common gray field slug, genus Arion (several colors of these large slugs), and the brown snail that is becoming more common as it can survive drier conditions easier than slugs.

Slugs eat young vegetables starts, strawberries, daffodils and tulips, and many other things, with new dahlia shoots and marigolds being among their favorites. You have to start early and be vigilant in your efforts to manage the slug and snail population in your yard. There is no such thing as just one slug. Slugs can lay anywhere between 30 to 100 eggs at a time, several times a year, mostly in late summer. Slugs are hermaphrodites: adults have both female and male organs, so all can lay eggs. Sometimes the eggs hatch right away and other times they hatch the following spring. Look for clusters of tiny, pearl-like eggs beneath leaf debris, boards, garden pots, and other damp places and crush them immediately.

Those little eggs will soon turn into ravenous baby slugs which eat 30-40 times their body weight every day! Their teeth are like a rasp that shreds the vegetation as they glide along. Slugs tend to come out at night or on cloudy days when it is cool and damp. This is your clue as to when to head out to hand-pick. However, only about 5% of the slugs are above ground at any given time, thus making control efforts difficult and ongoing.

There are five main types of control and for best results, you may have to utilize all of them, though you will never be able to eliminate slugs completely.

Biological:
Some predators eat slugs. Toads, frogs, snakes, and beetles will eat small slugs, so encourage them in your yard. Sometimes chickens and wild birds will eat baby slugs, but gag on large slugs. Ducks and geese eat slugs, but this poultry solution is not for everyone.
Cultural:
Change the conditions so the area is not conducive to slugs. Keep the soil dry. Mow nearby meadows or grassy areas. Keep a 6-foot-wide strip of dry, bare ground around your vegetable garden, use arborist chips for pathways, till your soil in early spring to expose the slug eggs, and plant things that slugs tend not to eat. Crushed eggs shells, ashes, and diatomaceous earth do not work. The slug’s mucus thickens to protect it from sharp surfaces.
Mechanical:
People love to talk about their favorite tools for slug control.
– A sharp shovel or weeding tool, a Hori-Hori knife, an old kitchen knife or scissors, or a hoe. Keep them all handy. Many people regularly go out at night or early morning with a bucket of soapy water on a search and destroy mission. The frequency is up to you, but the more often the better the results. Be sure to wear disposable gloves as slugs carry diseases such as Salmonella. Be sure to keep a lid
on the container.
– A wide band (3″) of copper tape firmly attached around the base of containers and raised beds will prevent slugs from climbing up. They will not cross copper. But make sure there are no slug eggs in the soil already in the pot!

This large red slug (Arion rufus) is one of the larger slug varieties, with an appetite to
match. This photo shows the slug’s round pneumostome (nose and breathing hole) and
the black optical tentacles protruding from its head. © Photo by Jason Miller.

Large red slugs descend on a pile of discarded raspberry canes. With voracious appetites,
these slugs can devastate many small plants overnight, skeletonizing the leaves and
diminishing the plants’ chances at survival. © Photo by Jason Miller.
Chemical:
There are many products on the market to kill slugs and snails. Read the label before purchasing and using it at home. Follow the directions exactly. The newer products are distributed differently than was done with the products of a few years back. Newer products use ferrous (iron) phosphate as the active ingredient and require only sprinkling sparsely over an area. Slugs are attracted to the bait, they eat it, and it makes them stop eating and slither away to die. You won’t see the dead bodies, but after a few days, you will notice the damage has stopped. These newer products remain active for up to 2 weeks, even if it rains. They are safe to use around children, pets, and wildlife.

There are some products available that use metaldehyde as the active ingredient and it works very well, but they can be poisonous to children, pets, and wildlife.

Home Remedies:
Do not use salt. Slugs rehydrate and salt damages your soil and plants. Fermenting yeast attracts slugs, so some people use beer. You provide the party, and the slugs show up, drink their fill and drown. It has its advantage. The slugs come to you; you don’t have to go out looking for them. You can use a cottage cheese carton, cut a couple of openings in the side, set it in the ground up to those holes, fill it with beer or your homemade brew, and put the lid on. Check and empty it every couple of days. Slugs are also attracted by the smell of dead slugs and show up to join the party. Keep your dog away since dogs are known to slurp up the whole thing, dead slugs, and all. You can use old beer, but not wine or stale beer. Apple vinegar sometimes works. You can also make your own fermenting recipe: 1 Tbsp brewer’s yeast or baking yeast, 1 Tbsp sugar, 2 Tbsp flour, and 2 cups tepid water. Mix and allowed to stand for an hour or so. It will last for 2 or 3 days.

Remember it takes regular attention and vigilance to manage slug and snail populations. Keep at it and over the years you will see a decline in the numbers you have in your yard.

About the Author:
Diana Wisen is a Skagit County WSU Extension Master Gardener and is the Coordinator of the Fuchsia Garden at the Discovery Garden on SR 536 in Mount Vernon.
References:
Gordon, David George. 2010. The Secret Life of Slugs and Snails-Life in the Slow Lane Sasquatch Books, Seattle, WA

“Managing Slugs and Snails” State University- 10-Minute University OSU Master Gardener Program and OSU Extension Service

Those Pesky Slugs” Article by Mary Robson King County Area Extension Agent (now retired) May 2000

Schenk, George. 2002. The Complete Shade Garden. Timber Press, Portland, OR

Questions about home gardening or becoming a master gardener, may be directed to:  WSU Skagit County Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, U.S. Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination.  To request disability accommodations contact us at least ten days in advance.