Cabbage is a biennial plant with green, red, purple, white, or pale green leaves that is mainly cultivated as an annual vegetable crop since the dense-leaved heads of the crops are consumable. It is a descendant of the wild cabbage and is closely related to cauliflower, broccoli, savoy cabbage, and .sprouts.Cabbage is a biennial plant with green, red, purple, white, or pale green leaves that is mainly cultivated as an annual vegetable crop since the dense-leaved heads of the crops are consumable. It is a descendant of the wild cabbage and is closely related to cauliflower, broccoli, savoy cabbage, and sprouts.