Winter sowing, as far as I can tell, is identical to what, in my self-education as a gardener, I learned as cold stratification. The more traditional description of the procedure is to put the seeds in the fridge for the requisite period of time, and then sow them in pots or flats or whatever your technique is for seed starting.
I learned stratification from Lauren Springer’s book The Undaunted Garden: Planting for Weather-Resilient Beauty. Her method is similar to what is commonly referred to as winter sowing now, but she didn’t bother with greenhouse-like containers to protect the pots of seeds. Instead, she covers the soil mix with “one-eighth inch of fine gravel (one or two grades coarser than sand)” and after watering them from the bottom, she puts “them outside on the north side of my shed, which stays shaded throughout the winter. This prevents the seed from experiencing the wide temperature fluctuations of warm, sunny winter days.” They aren’t covered because “The ideal cover…is a blanket of snow.”
This made sense to me, as it closely mimicked how the seeds would sprout in their native land under natural conditions, while still allowing the gardener the measure of control that most gardeners desire (like, knowing the names of the seeds that have sprouted). And when I tried it, it worked. This winter, observing that we have been having alternate thaws and freezes (it’s raining and 42F right now), I decided to use milk jugs and keep the containers on my porch. Even Lauren Springer says “if one lives in a climate with much winter rain, a cover over the pots is a great help,” and by keeping them on the porch, I am less likely to forget to check the moisture level of the pots when things get warmer in spring.
For the most part I have gotten away from growing plants from seed, after realizing that I never got the seedlings in the ground on time. But when Talitha was sorting through the family seed collection I found some perennial seeds for Iris setosa and Lobelia cardinalis and thought it would be nice to have some plants. And I also harvested some colchicum seeds and decided to try my hand at that as well.
Sowing seeds is a hopeful act, and preferable to moping about the length of winter. Unlike some people, I don’t expect to see crocus sprouts for another month, at least.