Winter Sowing
Ilove how winter sowing works with Mother Nature to give us a jump start on our early spring seed starting! Benefits to this system of seed starting include: earlier seedlings, re-use of existing plastic containers, no expensive equipment, no hardening off and stronger plant growth.
This method — around for more than 50 years — reuses plastic jugs and containers to create miniature greenhouses. This allows gardeners to harness the sun’s growing energy early in spring and add extra heat to the soil. This results in the seeds germinating faster, but not so fast that they can’t handle air temperatures once they break dormancy.
This practice was originally used to have a little more control over direct seeding native plants that needed that cold stratification period (a certain amount of time in freezing temperatures and the need for the freeze thaw process to break down seed husks).
MAKE A WINTER SOWING CONTAINER
First, save food-grade plastic containers such as milk jugs, takeout boxes, rotisserie chicken containers, water jugs or anything that has a clear-to-opaque top half.
Drill, puncture or melt drainage holes in the bottom of your containers. Add holes to the tops of anything that doesn’t have a cap you can remove. Cut open (with a box knife) if needed to allow access. (Leave a hinge in jugs, or just open takeout containers.)
Add seed-starting soil. Plant seeds at correct depth and water them in well. (Overseed now, as you’ll be transplanting anyway.)
Label your plants with a plant stake label in the soil and identification on the outside of the jug written with a waterproof and sunproof garden marker. Seal the cut opening with high-quality, waterproof tape. (I use silver duct tape.) Move the winter sowing containers outside to an area that gets good sunshine and has access to rain.
GROW ON
You’ll grow these seedlings on in the containers for a few more weeks after germination. Once the seedlings emerge, open the tops of the jugs as needed to keep your mini greenhouses from overheating. Transplant at the same time you’d normally transplant indoor grown seedlings. These plants tend to be a little stronger than those started indoors because they haven’t been coddled with the perfect indoor environment. But all this means is there are certain seeds that work better than others.
I most successfully use this process for cold-hardy spring vegetable crops, such as kale, cabbage, broccoli, Swiss chard, beets and lettuces. I’ve also had great luck with flowers such as poppies, calendula and marigolds. I love placing these winter-sown jugs inside my cold frames as well. This “double layer” effect bumps up my harvests another few weeks.
If you want more information on starting growing garden seeds, check out my blog, Forks in the Dirt, and most recent book, Small-Scale Homesteading.