Skagit County Master Gardener Foundation

Cultivating plants, people and communities since 1977

HARDENING OFF GREENHOUSE-GROWN PLANTS

Annual plants sold at the Skagit County Master Gardener Plant Fair, including tomatoes, veggie and herb starts, and flowers, have been started in greenhouses, protected from the elements of frost, wind, rain, and hot sun. Before planting them out in your garden they must be hardened off. This is the process that acclimates the tender, young plants to their new environment in your garden.

Start by setting your new plants outside in a sheltered, shady area such as a cold frame, covered porch or even under a tree. Try NOT to set your plants on the ground because of slugs. They would enjoy them right down to the base of the plant.

Keep the plants well-watered during the hardening off process. Start off with a couple of hours a day outside then move them back inside, sooner if the temperature drops. Do this for two or three days then go to a half-day, then on to a full day.

After a week the plants should be ready to be planted out making sure they are out of the wind. Apply balanced fertilizer regularly.

For more information...

For additional information about caring for new plants, check out these web pages and publications.

To get help

Talk to a master gardener for addtional help. Visit our plant clinics or farmer's market booths, or simply call or send us an email. Contact details are here.

Step by Step
Growing Tomatoes and Vegetables in the Pacific Northwest

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WSU Skagit County Extension
Plant Clinics

Let the Skagit County Master Gardeners provide science based recommendations for your gardening problems.

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Ask a Master Gardener Booths

Stop by and see us at Skagit County Farmers Markets for assistance with plants, trees, landscaping, and pests. We also have booths at public events such as the County Fair. Check the events page for a complete list of dates and times!