Why Winter Sow Native Seeds

Many seeds need cold stratification–that is, time in moist, cold conditions for 30-60 days, before they will germinate, to prevent them from prematurely germinating in the fall. Sowing native seeds directly onto soil seems like the most natural, and hence effective, way to grow them, but in fact, there are many reasons why direct sowing fails, especially in our disturbed urban soils. 

Winter sowing refers to sowing seed 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.

1. 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.

   

2. Native seeds are tiny, precious, and often expensive. The process of collecting, cleaning, and packing native seeds is highly labor-intensive, making seeds expensive. Winter sowing lets you handle them gently, sow thinly, and keep a careful track of what’s germinating.

3. It gives you flexibility. Maybe you’re still fighting the blackberries on the fence line. Maybe you’re waiting for that contractor who swore the deck demo would be “done in October.” Winter sowing buys you time. You can grow dozens (or hundreds) of sturdy plugs, then plant them out in clusters in the spring exactly where you want them. 

4. Natives want 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. Winter sowing gives them

   1. natural temperature swings

   2. natural moisture

   3. protection from heavy rain splash

   4. perfect germination timing

5. Winter sowing lets you 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. The classic YouTube method uses milk jugs, but I use a combination of 3.5” pots and take-out containers.

6. 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. Gardeners can plant clusters of species, which in turn helps pollinators as they search for their preferred nectar and pollen.

   

Buy Native Seed by Coverage

Seed orders are open now for pickup starting December 20. I’ve put together affordable single-species packets and meadow-by-color-palette bundles, designed for winter sowing and meadow building one square foot at a time. Each pack provides the correct amount of seed to grow one square foot of plants. Some varieties are also available in 5-, 25-, and 100-square-foot packs. 

East PDX Plant Club Native Seed Shop

On January 10, 2026, I am hosting a Winter Sowing for Habitat Gardens workshop.