Post: November 21, 2025

Subscribe to the Blog >

Dreaming and decision-making for a greenhouse

Questions and options to consider if a greenhouse is right for you

By Kari Ranten, Skagit County WSU Extension Master Gardener

 

 
Kari Ranten

The short days of the coming winter have gardeners missing the abundant growth, harvest, and busy days of the summer just past. Many are already dreaming about the potential of the upcoming growing season.

At this time of year, characterized by shortened days and gray skies in the Northwest, the opportunities for spring seem endless: What to grow? What seeds to buy? What were the favorites from seasons past that could be wintered over? Is there something new to try? More vegetables? More flowers? Something tropical?

With all of this potential, it makes sense that many gardeners’ thoughts turn to ways to fill the gardening void of winter. The likely answer may be to add a greenhouse to extend the growing season or make gardening a more year-round enterprise.

“When people make something by hand – with their own hands – it takes on a different level of value. So, it is with the food and flowers that we grow with our own hands. Having a greenhouse enables you to enjoy this therapy on a daily basis in any season,” writes Shane Smith, author of Greenhouse Gardener’s Companion, Growing Food & Flowers in Your Greenhouse or Sunspace (2000). Smith’s book is considered by many to be a must-have for those who desire or use a greenhouse. The Chicago Review Press notes Smith’s book is “The most comprehensive book on greenhouse gardening available today.”

The extension of the joy of gardening throughout the year is certainly a big draw. However, adding a “hobby” greenhouse requires considerable planning, decision-making, and resources. Winter may be just the season to spend time researching the idea of a greenhouse and to learn more about a potential project for the coming year. It takes some time to evaluate the right option for your specific goals, location, and budget, as well as address the myriad of questions that will come up. This column will pose some of the key questions you will want to ponder before moving forward with a greenhouse or other structure, such as a lean-to, cold frame, or tunnels. (Beddes, et al. 2022)

The most fundamental questions to start with are: What do you want to grow? How do you plan to use a greenhouse? Answers to these questions will help you get started as you dig into the details of location, space, materials, size, power, and lighting needs for a growing space.

A greenhouse can be used in a variety of ways. Before making a decision, know that each option presents a decision-making path to get to the ultimate plan for a structure that is right for you.

Here are a few considerations:

Want to start seeds? The first use that naturally comes to mind when thinking about adding a greenhouse is its use as a venue to get a head start on seeding flowers and vegetables, including tomatoes, squash, beans, and others, in early spring. Here, you will need to consider whether you want a heated or unheated space, based on the plants you plan to start.

“Because seeds like warm temperatures to germinate (often in the 65 to 75°F range), you will have to provide heat and light to help get your seeds to germinate. This can be done with LED grow lights and a heat mat, but that also means that you will need electricity in your greenhouse.” (Marshall, 2022).

Extending the season? A greenhouse can also be used as a season extender beyond summer, with fall planting of vegetables such as lettuce, spinach, and other greens, for harvest and enjoyment throughout the winter months. Heat and light requirements will also apply in this case. (Beddes, et al. 2022).

Protecting fragile plants? Suppose you want a protected place for delicate plants to spend the winter out of the cold, including cuttings of favorite perennials such as fuchsias, clematis, or herbs. In that case, a greenhouse can be a handy solution. Additional candidates may include geraniums and other annuals you want to hold over for another season. Some may not require a greenhouse; instead, they may need a garage or basement (Howard, 2025).

 

Tropical plants require a different environment than growing vegetables. Knowing which types of plants you want to grow helps you make decisions. Photo:© Adobe Stock

 

Tropical ideas? A greenhouse can be a year-round place for plants that may need a slightly warmer environment than our Zone 8b provides (https://planthardiness.ars.usda.gov/), such as citrus trees and orchids. “For example, it is said that George Washington grew lemon, limes, pineapples, and other tropical fruit in a greenhouse in 1787 at Mount Vernon. Glasshouses, as they were originally called, became the rage in England and later in America. They eventually came to be called greenhouses because the plants inside stayed green all winter long.” (Marshall, 2022)

Free-standing or lean-to? Designs and materials? Take advantage of resources on design options and materials to build with, including fiberglass, plastic, polycarbonate, and glass. Floor materials can also vary, including a slab, pavers, or gravel. Many do-it-yourself kits are available on the market, offering a wide range of sizes and amenity options. Design plans are also available online, offering options for building with recycled materials, including windows, doors, shelving, and other reusable building supplies.

Power? Heat? Lights? Ventilation? Research the climate and weather patterns where you live and match them with the desired use for the space to determine if you need access to power for heating, lighting, fans, or ventilation. An extension cord from the house may be enough. Otherwise, running power to the facility may be the right choice. Options can include space heaters, heat mats, and grow lights, which can be set to timers and scaled as needed. Technology also enables in-home, real-time monitoring linked to your cell phone, allowing you to view 24/7 conditions in the greenhouse, including humidity and temperature. Thermally activated automatic vents can also be installed and adjusted for temperature control. A drip watering system on a timer is also an option, or you can rely on rain barrels and watering cans.

Where will you put the greenhouse? How big should it be? A greenhouse requires a level area (or space that can be leveled) and meets the size and light needs. Many greenhouse owners caution gardeners to be honest about the space they need, based on their goals for use, to avoid an undersized project. Also, consider whether storage for gardening items, as well as plants, is needed.

What is the correct exposure? Ideally, the space will afford a south or southwest exposure to meet the daily sunlight needs of a greenhouse, which acts as a collector of solar heat. (Smith, 2000).

What about shelving or spaces to hang baskets? Plants, including seed starts and succulents, require more shelf space compared to plants in large pots. Pay attention to the materials used in greenhouse construction or the kit to make sure additional shelving or a bar for hanging plants is included or can be easily added. Gardeners recommend allowing for maximum flexibility to move plants, lights, and heat mats around as needed, while avoiding overcrowding.

Have a budget based on your decisions: With all these considerations in mind, they must match up with the project budget. “Before spending time and money, it is best to define your crop production goals, budget, and local climate challenges.” (Beddes, et al. 2022).

It takes work! Remember, once in place, the greenhouse requires ongoing maintenance, cleaning, watching for evidence of pests (like aphids, scale, etc.), disease (fungal and bacterial) and over- or under-watering (like edema or damping off), as well as regular time and attention – even with timers and automation.

For now, enjoy the dreaming and promise of spring.

Resources for more information:

Extending the Garden Season from Utah State University Yard and Garden Extension. 

The Hobby Greenhouse by Oklahoma Cooperative Extension Service.

References:

Beddes, T., Caron, M., Hansen, S., and Gunnell, J. (2022) Extending the Garden Season. Utah State University Yard and Garden Extension.

Chicago Review Press. (2025)The Greenhouse Gardener’s Companion 

Howard, D. (2025). How to Overwinter Plants: Protect Geraniums, Roses, Herbs & Tropicals From Frost. The Old Farmer’s Almanac. 

Marshall, R. (2022) A Greenhouse for Everyone. Massachusetts Horticultural Society. 

Schnelle, M., Dobbs, S., Needham, D., and Dole J. (2017) The Hobby Greenhouse. Oklahoma State University Extension Fact Sheet HLA-6705. 

Smith, S. (2000) Greenhouse Gardener’s Companion: Growing Food & Flowers in Your Greenhouse or Sunspace. Fulcrum Publishing. Golden, CO.

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: November 7, 2025

Subscribe to the Blog >

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 3, 2025

Subscribe to the Blog >

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: September 19, 2025

Subscribe to the Blog >

The Joys of a Cut Flower Garden

How to plan, grow, and protect a wide variety of beautiful blooms

Editor’s Note: Author Karen Bruce is passionate about growing a cut flower garden. Over the past ten years, she has honed her skills and enlarged her Camano Island garden to be able to cut 100 – 150 blooms each week for events and giving to others. Like so many cut flower gardeners, she is grateful for the beauty of the flowers blooming and the joy she finds in sharing the results of her passion with others.

---

By Karen Bruce, Skagit County WSU Extension Master Gardener

 

 
Karen Bruce

A cut flower garden brings not only colorful flowers throughout the growing season, but also bees, butterflies, hummingbirds and other beneficial visitors that come to enjoy the blooms. Gardening in general can teach us lessons if we pay attention. A cut flower garden’s lessons are vibrant in color and design. Planning a cutting garden begins in the fall with an assessment of this year’s garden and gathering seeds for next season.

The cut flower garden can consist of both annuals and perennials. Annuals grow and bloom for one year (occasionally they can overwinter but typically do not). Annuals can be planted from seed (most economical) or with starts or plugs from your local nursery, online sources, or the Master Gardener Plant Fair! Examples of annuals are sunflowers, zinnias, lisianthus, snapdragons, statice, Queen Anne’s lace, stock, and amaranthus.

‘Chantilly Bronze’ and ‘Madame Butterfly Bronze’ snapdragons © Photo: Karen Bruce

‘Love-lies-bleeding’ Amaranth and ‘Green Tails’ Amaranth © Photo: Karen Bruce

Perennials come back year after year; their initial investment is higher, but they will produce flowers that can be cut for many years. Examples of perennials that grow each year are alstroemerias, hydrangeas, hypericum berries, peonies, weigela, and astilbe.

Bulbs, tubers, and corms, if properly cared for, will come back each year. Examples of these are daffodils, tulips, anemones, ranunculus, lilies, gladiolas, and dahlias.

‘Bracken Sarah’ dahlia © Photo: Karen Bruce

Floral arrangement with lilies, dahlias, peach hypericum berries, apricot alstroemeria, ‘Spring Bouquet’ viburnum greenery © Photo: Karen Bruce
So you want to start a cutting garden of your own.
Things to consider when deciding what and how much to purchase:

• Why are you growing cut flowers? Is it for personal enjoyment? Are you creating bouquets and arrangements for special events such as weddings or memorial services? Are you growing to sell your flower bouquets at a farmer’s market or other venue?
• Are you are growing flowers for a special event next year? What colors, varieties and how many stems do you need? Consider the event date and which flowers will be in bloom at that time.
• What is your budget? Seeds can be purchased for as low as $4 to $6 per packet. Established plants will cost more but may be more predictable.
• How much space do you have? Will you incorporate the plantings into an existing garden? Are you going to create raised beds to grow your plants? Do you have a fenced area to protect your plants from deer or other critters?
• Do you have a greenhouse or area to start seeds, or do you need to purchase seeds that can be directly sown into your garden space?
• How much time and energy will you have to devote to your cutting garden?
  • Do you have the several months of time it takes to tend the growing seedlings?
  • Will you be around to take care of your plants, or do you have extensive travel plans?
  • Do you have adequate watering available?

Answers to these questions and your goals for your flower garden will help you plan for the season ahead.

Bells of Ireland © Photo: Karen Bruce

Peach Hypericum berry bush © Photo: Karen Bruce

Hops plant growing in garden. © Photo: Karen Bruce

There are many books available that can provide you with information about flowers you can grow to create beautiful cut bouquets. It is a good idea to look for an author who lives in your general growing area who will have an idea of what grows well in your gardening zone. A local favorite is Floret Farm’s Cut Flower Garden: Grow, Harvest, and Arrange Stunning Seasonal Blooms by Erin Benzakein, a well-known flower farmer and writer. Benzakein’s flower farm is located right here in Skagit Valley, and her New York Times best-selling book provides information on all types of flowers, along with photos of each flower. She also covers topics such as soil, tools, and techniques for seed starting and caring for your flowers once they have been harvested.

This Month in Your Garden

– 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.
• Stop dead-heading your roses and allow them to begin developing rose hips. The shortening hours of sunlight, along with allowing the rose hips to develop, lets the rose bush know it has done its job of making seed and can now prepare for dormancy. Remove wilted petals and any leaves with black spot, rust or mildew to keep any developing fungus away from plant.
• Deadhead perennials that self-seed, such as calla lilies, Shasta daisy, and crocosmia to prevent propagation.

Planning for next year’s cutting garden begins in the fall with the process of journaling and collecting pictures of what was successful, then making lists and ordering seeds, bulbs, tubers, corms, and plant starts and plugs.

In looking back at May/June, some favorite flowers were:

• Sweet peas
• Peonies – all colors
• Lilies
• Ranunculus – ‘Champagne’ and ‘Chamallow’

In assessing the July/August flower gardens, some current standouts this year are:

• Dahlias – Peach/coral and blush colors such as ‘Café au Lait’, ‘Sweet Nathalie’, ‘Castle Drive’, ‘Clearview Peachy’, ‘Nicholas’, ‘Ferncliff Copper’, and ‘Breakout’ are beautiful for event bouquets
• Snapdragons – This year, favorites are the ‘Madame Butterfly’ bronze/white and the ‘Chantilly’ pink snapdragons.
• Bells of Ireland
• Zinnias – The ‘Queeny’ series and ‘Benary’s Giant Mix’ provide big blooms in a variety of beautiful colors.
• Lisianthus – Because lisianthus can be challenging to start from seed, ordering plugs helps make growing them less anxiety producing. Farmer Bailey  is an online brokerage for starter plants and plugs for cut flower varieties suited to the United States. Here, lisianthus begin blooming in late August. If you want to try your hand at growing lisianthus from seed, check out our blog post Growing Lisianthus. 
• Alstroemerias
• Veronica
• Hypericum Berries – The peach hypericum (Hypericum inodorum ‘Kolmades’) or Magical® Desire St. John’s wort works well with other flowers from a cutting garden.

And don’t forget to have an ample supply of greenery to add to the look, color, and texture of an arrangement. These can include:

• Eucalyptus
• Viburnum ‘Spring Bouquet’
• Salal

October/November blooms will include chrysanthemums that are starting to form buds now. One of the first to bloom is a golden decorative chrysanthemum called ‘Honeyglow’.

Light pink lisianthus (or prairie gentian) © Photo: Karen Bruce

Floral arrangement with pink dogwood and mock orange © Photo: Karen Bruce
Every gardener benefits from reviewing and documenting successes and challenges.
To have continual blooms from June to October requires planning. Flower gardeners, such as myself, who grow flowers for events and sharing require 100 – 150 blooms per week. How is this possible you ask? Many flowers are cut-and-come-again. This means that you can cut from the plant, and new growth will provide additional flowers. For cut-and-come-again flowers to be successful, you must continually cut blooms from the plant and/or deadhead the ones that you do not use. Examples of cut-and-come-again flowers are dahlias, zinnias, cosmos, scabiosa, sweet peas, strawflower and statice.

Most cut flowers need to be planted in a sunny location with six to eight hours of sun per day. They also need to be watered on a consistent basis. A drip watering system saves time and avoids the need for much hand-watering. The consistency and deeper watering that comes from a drip system is helpful. Cut flowers also need regular fertilizing. Some years, annuals like snapdragons can survive our temperate winters. This past winter, many snapdragons survived, so that was an added success, providing many beautiful blooms earlier than usual in early May. As the snapdragons that overwintered finished blooming, the snapdragon seedlings started in the greenhouse provided new blooms later in the season.

Staking and plant supports are critical to protect flower stems from unexpected wind and rain storms.

Save the seeds of the flowers you like, this will increase your seed stock for next year at no additional cost. Some of the easiest seeds to save are sweet peas. After sweet peas are finished blooming, they form a pod that looks like a pea pod. When this pod turns brown and the outside feels like sandpaper, pick the pods and store them in a paper bag. If you open the pod, there will be several dark brown seeds per pod. Save these seeds to plant early next year. Other easy seeds to save are scabiosa, Bells of Ireland, Queen Anne’s lace, and zinnias. Be aware, some flowers, like zinnias are cross-pollinated and the seeds may result in a mix of colors and traits in the new plants. Learn more about seed saving at: Seed Saving 101

The greatest challenges to a cut flower garden tend to be deer, bunnies and slugs

If your property is situated next to the woods, you may have many resident deer. Gardeners protect their beloved flowers in various ways. The surest preventive measure is to build a fence around the areas devoted to flowers (and edibles.) For this gardener, a seven-foot-high fence was a good first start. Some gardeners even erect two parallel fences to thwart the most athletic deer. After discovering that the local deer do not seem to eat my dahlias, my dahlia beds are outside of the fence. Often, not all plants can be planted inside a fence, and scent-based repellents like Liquid Fence may also be helpful. Learn what deer like to eat and spray repellent around those plants about once a week (and after a rain) during the growing season. For more information see Washington State University fact sheet > Deer Damage

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
Sakuma Auditorium – NWREC WSU
16650 WA-536, Mount Vernon, WA 98273

---

 

Rabbits can also be a problem and some years can be worse than others. Fencing can work, but only if the fencing material is buried 6-12 inches deep and stands at least 2 to 3 feet high. Chicken wire cages around plants are helpful but also must be buried like fencing. Applying a pet- and child-safe rabbit repellent, such as Liquid Fence, is helpful, though it may take several weeks of attention. It also helps to have a dog or cat roaming the property to chase them away. WSU’s Hortsense website offers more tips and methods for protecting plants from rabbits> Rabbits

Healthy slug and snail populations are ever-present in western Washington gardens. Sluggo and Sluggo Plus are organic iron phosphate products that can be your best friend. Neither is harmful to animals or children and have been the effective way to deal with slugs and snails when applied according to their label directions. Some gardeners manage slugs and snails with early morning or late evening garden checks, manually picking and disposing of them. For more information check out:

• Skagit Master Gardener Blog article: Midnight Marauders≥ Midnight Mauradors: Managing Slugs and Snails

As summer is winding down and fall approaches, I am thankful for the flower season and the joy it has provided, as the giver and to those receiving flowers this season. Start small if you have never grown flowers before. See what you like and keep track of what grows well in your space and microclimate. Flowers provide joy to many and you will not be disappointed!

RESOURCES AND REFERENCES :

Benzakein, E. (2017) Floret Farm’s Cut Flower Garden: Grow, Harvest, and Arrange Stunning Seasonal Blooms. Chronicle Books, San Francisco, CA.

Managing Slugs and Snails. Oregon State University Extension Service. 10-Minute University™. (2025). Oregon Master Gardener™ Association – Clackamas County Chapter in Cooperation with Oregon State University Extension Service University. 

Vertebrate: Deer Damage. Washington State University (WSU) College of Agricultural, Human, and Natural Resource Sciences (CAHNRS). (2025). WSU Extension Hortsense Fact Sheet. 

Vertebrate: Rabbits. WSU. CAHNRS. (2025). WSU Extension Hortsense Fact Sheet.

ABOUT THE AUTHOR:
Karen Bruce has been a Skagit County WSU Extension Master Gardener since 2019. She is co-manager of the Cottage 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: 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.

Planting, growing and maintaining blueberries

Growing blueberries: Start with the right soil to get “superfood” results

How to choose blueberries well suited for success in the Pacific Northwest

Posted July 4, 2025

Subscribe to the Blog >

---

 

By Kari Ranten, Skagit County WSU Extension Master Gardener

Kari Ranten

Blueberries are a staple of Skagit County’s thriving commercial agricultural economy and are an increasingly popular plant and crop for northwest home gardeners.

Commercially, Washington leads the nation in blueberry production, with 26 percent of U.S. blueberries generating a revenue of $205 million, according to the U.S. Department of Agriculture (USDA-NASS.2025). Blueberry acreage in Skagit County increased eightfold since 2000. In 2023, 4,800 acres of blueberries were grown commercially in Skagit County, ranking third in crop acreage behind only field crops and potatoes, according to Washington State University Extension Skagit County’s Crop Acreage and Yield Report.

These strong statistics show that northwest Washington is an excellent growing environment for home and commercial production of blueberries, yielding a delicious summertime fruit crop or serving as a sturdy, attractive ornamental addition to the home landscape.

Blueberries have gained popularity among consumers for their nutritional qualities and are recognized as a “superfood,” offering an excellent source of essential nutrients, vitamins C and K, and dietary fiber. Blueberries are also a nutritional source of valuable “phyto-components,” contributing to antioxidants and anti-inflammatory qualities.

For those interested in growing blueberries in the home garden, there are some decisions and preparatory steps to take to get ready for planting from January to March.

Common varieties
Of the five main types of blueberries grown in the United States, northern highbush blueberries (Vaccinium corymbosum L.) are most common in Washington. These deciduous, perennial shrubs are shallow-rooted, take six to eight years to reach full production, and varieties can reach five to nine feet in height.

Researchers at WSU Mount Vernon Northwestern Washington Research & Extension Center (NWREC) play a vital role in working with commercial blueberry growers. Chakradhar Mattupalli, assistant professor of plant pathology, leads the Berry and Potato Pathology Program, conducting research and extension activities addressing the biology and management of diseases of highbush blueberry and potato crops. He provided guidance and resources in the preparation of this article. For more information about Mattupalli’s research, go to Berry and Potato Pathology | Washington State University

NWREC is one of four WSU Research Centers operated by the College of Agricultural, Human, and Natural Resource Sciences, housing nine research programs, extension outreach, and research affiliates. The research center works to solve plant-related problems and develop cost-effective and environmentally sound plant production practices based directly on results from experimental field, greenhouse, and laboratory research trials.

 

The publication “Blueberry Cultivars for the Pacific Northwest” notes that half-high blueberries, the result of crosses between northern highbush and lowbush blueberries, can also grow in the region and reach three to four feet tall. The cultivars are also used as attractive landscape plants and are suited to container production.

The NW Fruit Garden, next to the Discovery Garden on Memorial Highway in Mount Vernon, provides home gardeners with an excellent illustration of 30 blueberry varieties suitable to the local environment. The garden is maintained by volunteers, including Beth Jones, a NW Fruit volunteer since 2019, who leads the blueberry team charged with caring for 122 plants, some more than 20 years old.

Northern Highbush “Duke”

Northern Highbush “Draper”

Northern Highbush “Bluejay”

Start by selecting a location and testing soil acidity

Home gardeners can start by selecting the right location and soil for blueberry bushes. Blueberries require acidic soil with a pH of 4.2 to 5.5, similar to rhododendrons and azaleas, according to a 2025 presentation to Skagit County Master Gardeners trainees by Lisa Wasko DeVetter, associate professor of small fruit horticulture at Washington State University’s NWREC in Mount Vernon. Soil can be lab tested for pH, and if needed, acidification can be enhanced. A publication by Oregon State University Extension titled “Acidifying Soil for Crop Production West of the Cascade Mountains” provides a good resource on evaluating and enhancing soil acidity.

Because of the acidic soil needs of blueberries, home gardeners will need to plan ahead and prepare the space and soil before the arrival of the early spring planting season.

Blueberries can also be grown in containers and flourish in the full sun.

Plant selection, pollination, and care
Home gardeners should select two- to three-year-old plants (when shopping, ask at the nursery about plant age) and be on the lookout for those that are disease and heat-resistant “Legacy”, “Rubel”, and “Liberty”, have shown resistance to common diseases and rising summer temperatures in the NW Fruit Garden.

Plant blueberries from January to March, spacing three feet apart, in holes large enough to handle all of the shallow roots and allow three to four inches of soil to cover. Once established, blueberry plants are quite sturdy, with most producing fruit for 20 years.

While northern highbush blueberries are self-fertile, experts advise home gardeners to plant at least two different cultivars with overlapping bloom times in proximity to one another to benefit from cross-pollination and larger, earlier fruit.

All northern highbush blueberries are compatible with each other for cross-pollination.

Remove all flowers during the first year or two after planting to prevent fruit from setting and to give plants time to mature and enhance future yield.

Fertilize annually with a focus on nitrogen. For more information, see Oregon State University Extension publication EM 8857 titled “Nutrient Management for Blueberries in Oregon.” 

Blueberries require regular, supplemental watering from May to August and annual mulching with untreated wood chips.

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/

 

Prune each year in winter or early spring to eliminate any dead or weak shoots and select two to three new canes to retain for the next season. Prune carefully to retain the desired shoots, creating a vase shape that opens up the middle of the plant to provide air and light. Half-high cultivars do not need to be pruned as severely or as regularly as highbush types.

Healthy, established blueberry plants can yield more than one gallon of fruit per plant.

Blueberry plants can decline over time and should be replaced when they stop sending up new shoots during the growing season.

Pests and common diseases
A variety of pests and diseases can impact blueberry bushes and fruit.

Birds enjoy feasting on blueberries. To protect the fruit harvest from birds, home gardeners may want to cover plants with fine netting mounted on a frame and anchored to the ground from mid-June through harvest completion in August. If the bushes are growing for landscape purposes, let the birds have a summer snack.

Spotted wing drosophila, aphids, scale insects, root weevils, inchworms, and fruit worms can damage blueberry plants and fruit. To prevent or manage such infestations, refer to WSU’s publication “Growing Small Fruits in the Garden.”

In northwest Washington, blueberries are impacted primarily by two diseases: mummy berry and botrytis blight or gray mold.

Mummy berry is easily identified by the home gardener in the mid- to late- stages as the mature mummified fruit appears gray, shriveled, hard, and inedible. The disease is caused by a fungus that infects young flowers and vegetative buds in spring. About three weeks after primary infection, a brownish-gray mass of spores develops on blighted flower stalks and leaves that are spread by wind, rain, and honeybees (pollinators) to healthy flowers.

To manage the disease, the home gardener must remove the mummified fruit from the plant and lift it off the ground, add about two inches of mulch around the plants, and regularly disturb the soil during the spring. Healthy fruit can be harvested and used. At season’s end, clean the area to prevent infected berries from overwintering.

Blueberries, strawberries, and raspberries, especially on the west side of the Cascades, are affected by botrytis blight and gray mold. The cool and wet weather in western Washington is conducive to the development of this disease. Pruning creates airflow in the plant canopy, and reduced moisture on the foliage or fruit can help slow down the fungal growth.

REFERENCES AND RESOURCES:

Brun, C. A., DeVetter, L., and Benedicts, C. (2016) Growing Small Fruits in the Home Garden. Washington State University Extension Home Garden Series. Publication #EM103E

Finn, C., Strik, B., and Moore, P. (2024) Blueberry Cultivars for the Pacific Northwest. Oregon State University Extension Service. PNW #656

Hart, J., Strik, B., White, L., and Yang, W. (2020) Nutrient Management for Blueberries in Oregon. Oregon State University Extension Service. EM 8918. 

Horneck, D., Hart, J. Stevens, R., Petrie, S., and Altland, J. (2004) Acidifying Soil for Crop Production West of the Cascade Mountains (Western Oregon and Washington). Oregon State University Extension Service. EM 8857. 

Pscheidt, J.W., and Ocamb, C.M. (2025a). Blueberry (Vaccinium corymbosum)-Mummy Berry.  Pacific Northwest Plant Disease Management Handbook. Oregon State University. 

Pscheidt, J.W., and Ocamb, C.M. (2025b). Blueberry (Vaccinium corymbosum)-Botrytis blight. Pacific Northwest Plant Disease Management Handbook. Oregon State University.

Washington State University Northwestern Washington Research and Extension Center. (2025) Berry and Potato Pathology.

Washington State University Skagit County Extension Skagit County Agricultural Statistics. (2024) Crop Acreage and Yield Report.

Yan, L. (2023) Blueberries and Health. USDA Agricultural Research Service.

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 Master Gardener 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.

What’s in Your Bag of Potting Soil?

Not All Potting Soils Are Created Equal

              Subscribe to the Blog >

By: Bruce Lindsay, Skagit County WSU Extension Master Gardener

As spring advances, gardening stores offer a multitude of soil mix choices. Selection can seem daunting, so we asked fellow master gardener and soils expert Bruce Lindsay to take us on a deep dive into what potting soils are made of and how to amend commercially bagged potting soils to ensure the best success in our container and raised bed plantings.
                                                             — Ask a Master Gardener Editors
What exactly is in a bag of commercially produced potting soil?
The first step is learning the basics of soil. All soil primarily consists of sand, silt, and clay mineral particles. Sand is visible to the naked eye, ranging from 0.05 to 2mm in diameter, and is gritty to the touch. Silt is not visible to the naked eye and looks and feels like flour when it is dry. When it is wet, it feels like damp flour dough. Silt ranges from 0.002 to 0.05mm in diameter. Clay is the size of bacteria, less than 0.002mm, and has colloidal properties as the result of its net negative charge due to its crystal structure. In a natural setting, soils have pores made by plant roots and insects, which are essential for drainage and allowing air to enter the soil for roots to breathe. The size of the pores is also important for water movement and the soil’s ability to retain water.

In contrast to well-balanced mineral soil, purchased potting soil typically has very few of these properties and has several problems. But take heart, armed with scientific knowledge, gardeners can remedy many of these deficiencies.

The vast majority of bagged “potting soil” consists of ground wood and bark produced from recycled forestry products (RFP). Commercially bagged soils are available in multiple mixtures containing RFP, peat moss, and other additives. © Photo: Adobe Stock

For seed starting and plant repotting, master gardeners use a moist, good quality potting soil mixed with perlite. © Skagit County WSU Extension Master Gardeners

The vast majority of bagged “potting soil” (technically called a potting “medium” even though the label calls it “soil”) consists of ground wood and bark produced from recycled forestry products (RFP). Various commercially bagged soils are available, from coarse bark to multiple mixtures of RFP, peat moss, and other additives. In contrast, mineral soil products combine mineral particles of various sizes with some added compost. The potential hazard with some commercially bagged soils is the possible presence of weeds such as horsetail (Equisetum) and the potential presence of herbicides coming from landscaping sprayed with herbicide or hay fed to animals that has been sprayed and persists through a composted state and cause damage when used as potting soil.

Dealing with Nitrogen Deficiencies 
Recycled forest products are commercially sold in large bark chunks as mulch and finer-grained material as potting soil. These products come with inherent problems that gardeners can solve with amendments. The first issue that must be addressed is the carbon-nitrogen ratio (C/N). The ground-up wood materials in these bagged soil products are often almost pure cellulose, and bacteria (microorganisms) love to eat it. When bacteria eat stuff, they make many more bacteria and require more nitrogen as they reproduce, which results in nitrogen deficiency, leading to poor plant growth.

Older leaves turning yellow while the young leaves are green is often a sign of nitrogen deficiency. Severe nitrogen deficiency results in a severe lack of growth and stunted plants. One must take care when adding nitrogen; too much will promote rapid growth and excessive foliage. It can be a tricky balance, but fertilizer with some phosphorous and potassium is best. Some fertilizers also contain micronutrients, which can be beneficial. Use a significantly diluted solution (1 TBSP per gal.) of soluble fertilizer and frequently monitor the plants to see how they are doing.

Perlite is a volcanic glass, which, when subjected to heat and pressure, it changes, puffs up like popcorn, and forms many tiny pores that can hold water.

It is surprising how much wood is included in a bag of potting soil. © Skagit County WSU Extension Master Gardeners

Since the recycled forest products used in commercially sold products are very porous, much of the fertilizer will drain through the pot in one application. To solve this problem, use well-composted materials containing organic matter or humus for effective nutrient retention. Well-composted materials should not include a lot of materials like straw and sawdust. Bacteria love sugars and cellulose, as in the “greens” of composting terminology, but bacteria have a hard time breaking down the “browns,” which contain lignin. If there were only sugars and cellulose in composting, bacteria would consume everything, and nothing would be left. The compost “browns” in soils contain materials high in lignin, resulting in “humus” as the ultimate end product of composting. One benefit of humus is that it is very good at holding water. Another significant advantage of adding well-composted materials to a soil mixture is that it will also add beneficial bacteria and fungi that are essential for many processes, just as they are in healthy mineral soils. Another benefit is that humus has a net negative charge that can hold onto cations such as potassium, calcium, and magnesium, giving the soil cation exchange capacity essential to plant growth.

The Importance of Cation Exchange Capacity (CEC)
Balanced mineral soils contain clay particles with a negative charge that hold onto the cations. Bagged potting soils containing a heavy ratio of recycled forest products do not have any clay, so the cations get leached out. To amend this problem, add well-composted materials to the RFPs. Hydrogen ions are cations that stick to negatively charged humus particles like little magnets. When fertilizers are applied, the calcium, magnesium, and potassium displace the hydrogen cations and become stuck to the humus particles. Plant roots come along, exude acids, and displace the nutritional cations, which are absorbed by the root and go up into the plant.
Wikipedia defines CEC as:
Cation-exchange capacity (CEC) is a measure of how many cations can be retained on soil particle surfaces.[1] Negative charges on the surfaces of soil particles bind positively-charged atoms or molecules (cations), but allow these to exchange with other positively charged particles in the surrounding soil water.[2] This is one of the ways that solid materials in soil alter the chemistry of the soil. CEC affects many aspects of soil chemistry, and is used as a measure of soil fertility, as it indicates the capacity of the soil to retain several nutrients (e.g. K⁺, NH₄⁺, Ca²⁺) in plant-available form. It also indicates the capacity to retain pollutant cations (e.g. Pb²⁺)

Many garden centers now carry a soil amendment called humic acid (or related substances, humin and fulvic acid). These are still the subject of much scientific debate. These compounds are created by alkaline extraction and are not naturally present in soil. While humic substances may have some positive effects on root growth, home gardeners are best advised to focus on the longer-term building of soil organic matter through carbon-rich amendments such as compost (or cover crops for garden beds), etc.

The Soil‘s Capacity to Hold Water
It is essential to slow the water down so plants have the opportunity to absorb it. Fortunately, most ornamental plants and vegetables prefer well-drained soil and do not like being in standing water for very long. In contrast, due to their fibrous material, most hanging baskets need watering once a day.

Add popped perlite and/or vermiculite to the mix to increase water retention. Perlite is a volcanic glass, which, when subjected to heat and pressure, it changes, puffs up like popcorn, and forms many tiny pores that can hold water. Perlite is the little white balls often added to soil mixes.

Vermiculate is a naturally occurring mineral that is also heated to create the golden-brown cube-like material we see added to soils. Vermiculite draws in and holds water like tiny sponges throughout the soil. You can also use coconut coir as a moisture-holding material, but soak it thoroughly before adding it to a mixture.

The water-holding capacity of pelletized wool is an exciting new material being tested. Pelletized wool is composed of the short wool fibers from the underside of sheep where the wool is also much dirtier and has plant fibers embedded; it is not suitable for processing into fabrics. This material has been a waste product of the wool industry. Recently, however, research has shown that this material is a viable amendment to soil that improves the water-holding capacity of soil and provides some slow-release nutrients. Already sold commercially this material is pelletized for ease of mixing into soil and is a productive, sustainable use for a by-product typically diverted to a landfill.

The Addition of Slow-Release Fertilizers
Bagged potting soil products often offer slow-release fertilizer additives. Beware of those using tiny plastic beads to store the nutrients. Our soils do not need synthetic materials left behind. Instead, some products use fertilizers with a mineral coating, such as limestone or gypsum, that slowly dissolves, releases the inner contents, and does not leave behind plastic residue.

Other slow-release products consist of blood, bone, and feather meal, which are by-products of meat processing. The drawback of these materials is the smell they generate. They are acceptable when used in a field but not welcome on a patio in a hanging basket. Likewise, fish emulsion is a fairly slow-release fertilizer but also has a considerable odor problem. While it is an organic fertilizer, one must consider the odor it causes and that it is a by-product of overfishing of oceans.

Adding ground limestone to the mix may be a good idea because the recycled wood product material tends to be on the acidic side. The limestone will add some alkalinity. Dolomitic limestone is even better, as it contains magnesium and will be a slow-release source of calcium and magnesium. Be sure to mix it well with the potting soil. About a cup per cubic yard should be enough. If you have access to a pH tester, use it! The soil pH indicates the availability of essential nutrients needed for plant growth. Ideally, potting soil should have a pH of about 6.5. It is important to test the pH of your soil mix before adding an amendment to raise or lower the pH.

Basic food waste from the farming, grocery, and restaurant industries is a readily available slow-release fertilizer. It is stunning that forty percent of our food production goes into landfills. An alternative is an organic liquid product made from fermented food and vegetable waste. It doesn’t stink and smells good, somewhat like soy sauce. With landfills overflowing, diverting food waste into soil improvement and garden production is one way to improve our environment.

Some people think replacing their potting soil with fresh material each year is necessary. This is only the case if there are disease issues. For instance, potting mix used for tomatoes or potatoes should not be used again for those plants because they are both susceptible to soil borne diseases. After a season of growing and watering, all the nutrients have leached out, but you can easily replace the nutrients by using the dilute fertilizer solution mentioned above. If the soluble fertilizers are too concentrated and the plants are not utilizing them, they may accumulate as salts. As time passes, some of the RFP in the potting soil will get eaten by bacteria, and the volume will decrease. In this case, add new potting soil with the amendments and mix it well with the original soil, spreading the nutrients around.

These recommendations apply to soil used in containers, raised beds and hanging baskets. It also applies to starting seeds in trays, but the seed starting soil material should be very fine to ensure good contact between the seed and the moist growth medium. When starting seeds, the soil should also drain fast enough so a fungal damp-off situation does not develop. Sphagnum peat moss tends to float to the top when watered and begins to clog pores, making it difficult to get moisture down to the bottom of the cell. Sprinkling fine vermiculite on the very top of each cell can help prevent these problems.

While forestry products recycled as commercial potting soil have drawbacks, amending these insufficiencies is an easy process. It is much better to use RFP products than to burn, bury, or dump them into the overflowing waste stream. Armed with awareness of the limitations of modern “potting soil” and knowing some remedies, gardeners can buy these products feeling confident with scientific knowledge.

REFERENCES AND RESOURCES:

Beck, L. (2023). ‘Waste Wool‘ is a Burden for Farmers. What if it Could be a Solution Instead? Retrieved from https://modernfarmer.com/2023/11/waste-wool-solution/

Brady N., Weil, R. (2017). The Nature and Properties of Soils. London, UK. Pearson Education (15^th ed.)

Lehman, J., Keber, M. (2015). The Contentious Nature of Soil Organic Matter. Nature volume 528, pp 60-68.  https://www.nature.com/articles/nature16069

ABOUT THE AUTHOR :

Bruce Lindsay became a Skagit County WSU Extension Master Gardener in 2015. With an MS degree in geology and an MS degree in soil, he has mapped soils in Nevada, Arizona, California, and Washington.

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

Upcoming Skagit Master Gardener Foundation Events:

Know & Grow:
Growing Roses in Skagit County – Free
Presented by Virgene Link-New
April 16, 1 p.m. 
NWREC Sakuma Auditorium
(16650 State Route 536, Mount Vernon)

Free Admission & Parking
May 11, 8 a.m. to 2 p.m.
Skagit County Fairgrounds
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!

---

 

Discover the Skagit Valley Display Gardens Open House

Discover the Discovery Garden, NW Fruit Garden, and the Salal Native Plant Garden

              Subscribe to the Blog >

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