Any claim about winter production of fresh vegetables, with minimal or no heating or heat storage systems, seems highly improbable. The weather is too cold and the days are too short. Low winter temperatures, however, are not an insurmountable barrier. Nor is winter day-length the barrier it may appear to be. In fact most of the continental US has far more winter sunshine than parts of the world where, due to milder temperatures, fresh winter vegetable production has a long tradition.