I don't know how our winter temperatures compare, but I bought a coldframe for my garden in the fall and have a # of things growing there now: 3 kinds of lettuce, silverbeet, spinach, parsley, kale. Siberian kale would likely grow out in the open w/o the coldframe. It was 18 degrees here last night and I just picked a salad for lunch. If it is very cold where you are, you may have difficulty getting seeds to germinate. Also, if they do, they will grow more slowly than in season. My plants were grown from seed in September and are only now producing plants large enough for picking.
Starting Weight: 197.5
Current Weight: 123