It depends on how you define "wintersowing". I think of it as sowing seeds in a vented, covered container, outside. I use milk jugs almost exclusively. I put out perennials in the winter time, but tender annuals, including tomatoes, I don't do until very late winter or early spring. The problem with sowing tenders (think tomatoes) in January is that in most of the country, as days start to lengthen, we get unusually warm days. Tender seeds can sprout in one of these early warm spells, only to freeze to death when the winter weather reappears.
I had great results wintersowing my tomatoes for several years, but then two years ago the weather stayed so cold that very few sprouted by May so I had to go out and buy plants. Last year, I started them inside under lights, and I was glad I did. Weather stayed so cold throughout spring that I had more plants than I knew what to do with inside. I ended up buying one of those little mini greenhouses for extra plant space.
Karen
