Winter C.S.A.s rely on the same food growing and preservation methods that people in cold climates always have: fermenting; canning; freezing; extending shelf life in root cellars; drying foods; and extending growing seasons with cold frames, hoop houses, and greenhouses.
A winter C.S.A. takes foods grown all summer long and prepares them for storage, as well as collecting wild foods and working with four season farmers.
Summer C.S.A.s abound in the Hudson Valley, but winter C.S.A.s are just starting to crop up. I only know of Wintergreens and our friends at Winter Sun Farms. Support the movement! Eat locally and well throughout winter.