Resembling a tennis ball sprouting kale leaves, kohlrabi looks odd but tastes great. Leaves and leafstalks of this cabbage relative are edible, but most gardeners grow it for the enlarged, bulblike part that forms just above the soil surface. Probably native to Europe's west coast. Plants go from seed to harvest in 50 to 60 days; the quality declines if harvest is delayed.
Standard selections are 'Early White Vienna' and 'Early Purple Vienna'similar in size and flavor, differing only in skin color. They're ready when globes are 23 inches in diameter. Other white selections include 'Triumph' and early-maturing 'Grand Duke'. 'Kolibri' is a popular purple-skinned variety with 46 inches globes. 'Superschmelz', 'Kossack', and 'Gigante' all reach 810 inches in diameter.
Harvest bulbous part when 23 inches wide. Peel, slice, and serve raw; or steam or saut slices or chunks. Steam young leaves and leafstalks.
Plants are very fast growing, ready to harvest in 50 to 60 days from seed. Sow seed in rich soil about 2 weeks after average date of last frost. Before planting, work cup of 10-10-10 fertilizer per 10 feet of row into soil. Follow first planting with successive sowings 2 weeks apart. In areas with warm winters, plant again in late fall and early winter. Sow seed 12 inches deep, in rows spaced 112 feet apart; thin seedlings to 46 inches apart. Cabbageworms are the primary pests. For controls, see Cabbage.