Winter sowing is a gardening technique that repurposes single use plastic such as one gallon milk and water jugs, plastic food take-out and chicken rotisserie containers, and other food grade containers to grow vegetable and landscaping transplants cheaply.
I live in USDA hardiness zone 4 in SW Minnesota. I’ve used the winter sowing method to raise all my early spring cool season broccolini, lettuce, kale, and spinach vegetable transplants. I’ve grown butterfly weed and echinacea (coneflower) transplants for pennies.
Not only does this gardening technique repurpose single use plastic containers it requires no indoor grow lights. This method is in sync with creation. The planted plastic containers are placed outside in a wind protected area. For the seed of native plants such as butterfly weed and echinacea that requires cold stratification, containers are placed outdoors in January and February. In my Zone 4 location I set out cool season crop containers in early March. While I start warm season tomatoes and pepper transplants indoors under grow lights, I’ve experimented with setting out tomato and pepper winter sowing containers the first half of the month of April. Initially, the resulting transplants are smaller than the indoor grown plants when set out in the garden. Because the winter sown tomato and pepper transplants are acclimated to the outdoors, no hardening-off time is required. And, with minimum transplant shock the plants nearly catch-up with the indoor raised transplants. The winter sown transplants have provided an abundance of late summer yields.
Those living in warmer USDA hardiness zones will need to adjust winter sowing dates. For more information about your hardiness zone and the appropriate varieties to plant for your area, contact your local land grant college Extension Outreach office or seek out Extension Master Gardeners in your county.
There are several online sources for winter sowing information. Below are a few credible sources:
