Any biannual vegetable such as the collards and carrots will winter over and can actually be harvested fresh in the dead of winter. These vegetables take two years to go to seed, so an extra large crop of carrots, cabbage, etc. can be left in the ground all winter to provide fresh food through the winter into spring. When spring comes, plant radishes and spinach for fast results. Typically, you can harvest fast vegetables a month after planting.