Kohlrabi is one of those strange plants that when you first see it growing you think it might just be from another planet. Many people who only ever see it being sold at markets assume it must be a root vegetable, but the part we eat is actually a swollen stem. Like Brussels sprouts, kohlrabi is a relatively new development in the cabbage family, believed to descend from wild "marrow cabbages" that grow along the coast of Northern Europe. Its first written mention comes from an Italian botanist (Mattioli) in 1554, who said it had "come lately into Italy." By the end of the century it was being grown in Austria, Germany, England, Italy, Spain, North Africa, and parts of the eastern Mediterranean. Today, it's become a part of the food culture in countries as far away as Vietnam, Sri Lanka, and India.
The flavor and texture is similar to cabbage heart or broccoli stem, but it is crisper, sweeter, and more mild. It can be eaten raw or cooked. We like to make flash pickles (or "quickles") by slicing them into strips and soaking them in salted vinegar with spices for just a few hours. The flesh quickly takes up all the flavor while retaining its superlative crunch. Kohlrabi leaves are also delicious, and the stems also make good pickles.
'Early Purple Vienna' and 'Early White Vienna' are like two different-colored sides of the same coin.
These seeds were grown to us by our friends Kass McKinnon and Clint Freund of Cultivating the Commons in Wisconsin.
GROWING TIPS: Grow like you would kale or broccoli, but you can space kohlrabi a bit closer together (8 inches works fine). Harvest for food when the bulbous stems reach around three inches in diameter. Larger than that they can begin to get woody. For seed saving, they are biennials and so need to be overwintered. Digging them up and keeping the roots in moist sand in a root cellar is ideal.