Kohlrabi is a small, fast growing member of the Brassica family, with an unusual appearance. The spherical swollen stems, sitting just above ground level, are picked at tennis ball size. The crop can be harvested almost all year around. Kohlrabi makes a good catch crop or an interesting addition to an ornamental garden. It can also be grown in containers.

Green cultivars are usually grown for spring and summer crops, the hardier purple varieties for autumn and winter use. New hybrid cultivars grow larger without become woody. Organic and heirloom varieties are available.

Ideal Site- This crop prefers an open, sunny fertile site. Prior to planting apply a low-fertility soil improver or one of medium fertility for poor soil. Kohlrabi is suitable for early and late production undercover in greenhouses or hoop houses. The ideal soil pH is 6-7.

Seed to Harvest- 5-9 weeks depending on cultivar

Cultivation- Sow every few weeks for a regular supply, as kohlrabi will not stand in an edible condition for long once ready. The minimum germination temperature is 50F(10C). Undercover: Sow it in cell packs from late February through August. Plant cut when no more than 2 (5cm) high. Sow in September to grow undercover Outside: Sow direct from March to August. Use the hardier purple cultivars for later sowings.

Spacing- Rows: 7 x 12in (18-30cm) Block Planting: 10in (25cm)

Plant Care- Water in dry weather, Kohlrabi is fast growing - and tends to be problem free- though it is susceptible to the same pest and diseases as other brassica plants.

Problems- Flea beetle, cabbage root fly, cabbage aphids, and clubroot.

Harvesting- Kohlrabi tend to mature quickly so check and harvest regularly. Cut older varieties when no larger than a tennis ball. Modern kohlrabi varieties can grow to 4in (10cm) in diameter without getting woody. Later crops can be left in the ground until a hard frost is forecast, or up to 2 months in boxes of moist sand. The vegetable has a fresh, crisp, juicy taste when eaten raw or lightly cooked.

Nutrients- Kohlrabi is a very nutritious vegetable containing vitamins, A,C, B6, Folate, thiamin, dietary fiber, calcium, phosphorus, potassium, manganese, copper, selenium, and iron.