Winter Sow a Meadow

Chris Musser
Dec 5, 2025
4 min read

Updated: Jan 3

Winter sowing refers to sowing seeds in pots during the winter, covering the pots with a transparent lid, and leaving them outdoors, unprotected from the cold. It is a technique that gardeners have used for all manner of flower and vegetable seeds, and it is especially well-suited for starting natives from seed.

Benefits of winter sowing native seeds

The biggest benefit of winter sowing in pots, compared to direct sowing, is how dramatically more successful it is. Habitat restoration literature reports 70–90% success with native plantings from plugs, vs 10–30% success with direct seeding. Winter sowing

Protects your seedlings from slugs and snails. Direct-sown seedlings are a buffet for invasive European slugs that thrive in disturbed soils, such as hellstrips and converted lawns. Winter sowing puts seedlings in mini greenhouses and out of the slimy reach of land mollusks.
Eliminates weed competition during germination. It's virtually impossible to remove weed seeds in open soils, especially in urban areas full of weeds, and wildlife that eat their seeds and leave them wherever.
Provides soil that triggers and supports root growth. Seedlings struggle to grow in compacted, poorly drained soils that host pathogens.
Sowing in pots gives you the opportunity to observe your plants up close. You can learn to identify seedlings and take their baby pictures, which will be especially useful later when playing Is it a Weedling or a Seedling next spring.
Naturally provides cold, wet stratification. Pacific Northwest native plant seeds evolved to sit outside all winter, freeze, thaw, soak, freeze again, and then wake up in spring. No plastic bags of wet sand and seeds in the fridge for months!
Set it and forget it. Unlike starting seeds indoors, winter sowing doesn’t require lights, warming mats, watering, misting, fertilizer, etc. There’s no dampening off or spider mites.
Seeds together strong. Winter sowing lets you transplant in hunks. Many native seedlings prefer to grow in small clusters. They support each other, shade the soil, and transplant well as a unit. Native plugs have significantly higher survival than direct-sown seeds, specifically because they can outcompete annual weeds early.

Winter sowing basics

Gardener Trudi Davidoff developed the winter sowing propagation method about 25 years ago when she was struggling to find space to start seeds inside her home in New York. Her solution: cut gallon milk jugs in half and poke them with holes for drainage. Fill the bottom of the jug with potting soil, sow seeds, tape the top on, and set outside all winter.

That approach works well for many gardeners, but for Pacific Northwest native plants, it can be simplified even further. When I first started winter sowing, I wasn’t keen on finding, cleaning, cutting, and taping plastic milk jugs, and then cleaning and storing them. I sow seeds in 3.5” pots, set the pots in a shallow tray, cover the tray with tulle or a clear plastic dome, and set the tray outside.

Caveats

You can use potting soil for winter sowing, but bagged potting soil is generally too moisture-retentive and contains too much fertilizer for native seedlings that prefer quick-draining, lean soil. I make a soil mix with fine pumice, coco coir, sand, soil, and worm castings.

Pumice provides drainage and aeration.
Coco coir provides structure, holds moisture, and improves fungal resistance.
Sand also provides drainage and aeration, and aids seed-to-soil contact.
Soil acts as a probiotic, with native microbes that help seedlings transition from dormancy to growth and support mycorrhizal relationships when transplanted.
Worm castings have “root signaling” substances, such as humic acid, that triggers root growth and boosts nutrient uptake.

Most PNW native seeds are tiny! It’s important to sow the correct amount of seed. Seeds planted too densely may not germinate at all! Too few? Nobody wants too few. Based on recommended sowing rates, I weigh or count the amount of seeds for one square foot, and sow that into a 3.5” pot. When it’s time to transplant, the pot is divided into clumps and planted in a one-square-foot area.

Grasses and creeping thyme in takeout containers, guarded by tree collards.

Buying Club Magic

I have put together Winter Sowing Kits, with my winter sowing potting mix, pots, germination tray, tags, tulle, clips, and instructions for winter sowing PNW seeds. I pack seeds according to square feet of coverage. Each one square foot pack can be started in one 3.5” pot.

Right Plant, Right Place

One of the beauties of growing native plants is that they only need to be planted in the right conditions to thrive. With winter sowing, you can set out each species in the most suitable conditions in your yard. On the website, I have added a filter to find seeds and plants for the following conditions.

Moist meadow plants prefer damper soil. Place them in low spots, rain gardens, and summer-irrigated areas.
Open meadow plants thrive in clay soil and three months of no rain that is summer in Portland.
Upland meadow plants prefer fast-draining, lean soil. Excellent for rock gardens and steep hillsides.
Bog and Wetland plants want constantly wet feet.
Woodland edge plants want to be on the wood’s edge. Or some edge. They’re edgy.

Native Seeds by the Square Foot

Each single-species packet contains the correct amount of seed to grow one square foot of plants when winter sown. Some species are also available in 5-, 25-, and 100-square-foot packs. Visit the East PDX Plant Club Native Seed Shop

Seed orders are open now for pickup starting January 10, 2026, when I’ll be hosting a Winter Sowing Open Carport. I’ll have my winter sown nursery set up and be around to answer questions.