Resembling a spaceship or satellite, the swollen stem or "bulb" of kohlrabi develops just above the soil line. The crisp, sweet flesh resembles that of turnip and is used about the same way. Peel, slice, and eat the bulb fresh, or dice and cook it in soups and stews. Kohlrabi grows best in mild weather. Harvest the kohlrabi when the first stem is 1" in diameter. Kohlrabi can be continuously harvested, up until the stems are 2-3" in diameter.