Kohlrabi

by Barb Henny

In the Himalayan Mountains in India tonight, a woman is preparing a traditional supper for her family. She steadies a kohlrabi on her cutting board. With a sure, swift slice of her knife she removes the leafy top. She slices away the bottom then peels off the rind. She chops the cleaned vegetable, which she calls knolkol or navalkol, and adds the diced kohlrabi into her lamb curry. As soon as the vegetable is tender, she’ll serve her family their evening meal.

 Kohlrabi has been recorded as a dietary staple in Northern India since the 1600s. Kohlrabi is also well established in vegetarian cuisines in China and Africa. The purple colored varieties of kohlrabi taste like radish; white varieties have a delicate flavor similar to broccoli.

Kohlrabi is a member of the Brassica plant family. Kohlrabi, broccoli, kale, cauliflower, cabbage, and collards are so closely related that they all have the same scientific name: Brassica oleracea. Like the iconic characters from the Bob Newhart television show “Daryl, my brother Daryl, and my other brother Daryl," Brassica plant family genetics are tightly knit. In the case of kohlrabi, the name means “turnip cabbage” and the edible portion is the enlarged stem.

Kohlrabi is a cool season crop in Florida. North Florida can plant in October and November and in the spring as late as March and April. Central Florida plants kohlrabi in October and November for a fall harvest and plants in February and March for a spring crop. South Florida enjoys planting kohlrabi in November, December, January and February. Kohlrabi will tolerate light frost in wintertime, but hot weather will cause the edible stem to become woody.

The traditional varieties of kohlrabi are Purple Vienna and White Vienna. Many other hybrids are readily available. Sow kohlrabi seeds into a pre-moistened 6 inch pot of peat. Cover the seeds about ¼ inch deep then keep them in a warm spot until they germinate. Germination should take 5 to 7 days. Move the seedlings to a high light area such as a hobby greenhouse or a very bright windowsill to prevent stretching. It may take 4 to 6 weeks to grow transplants to size before moving out to the garden.

Transplant seedlings to a full sun location into soil that has been pre-moistened and is well amended with compost. Kohlrabi does not like to become dry. Water 1 to 2 inches per week since roots are shallow. Drip irrigation along with mulch can be used. Toughness will result if moisture is not evenly maintained.

Allow 6 inches between plants and 24 inches between rows. Fertilize initially with a liquid fertilizer at half strength. As kohlrabi plants become established, apply your favorite balanced granular fertilizer about every 2 weeks.

Pests are relatively few on kohlrabi unless broccoli, cabbage, or other Brassica family crops are planted nearby. Because they are all so closely related, a disease that attacks one attacks all. Alternaria leaf spot, downy mildew, and clubroot await opportunity to infect these crops and wreck your harvest. Identify and treat problems as soon as they erupt. Leaf chewing caterpillars are always a pest in a fall garden. Treat with Bacillus thuringiensis (Bt). If aphids become a nuisance on kohlrabi, treat with a horticultural soap.

Depending on your conditions and the variety you choose, kohlrabi should be ready for harvest in approximately 70 to 80 days. Harvest promptly when the “turnip-cabbage” is 3 to 4 inches in diameter. If left too long, stems grow tough and fibrous. Remove the kohlrabi plant after harvest; it will not re-grow.

Kohlrabi can be cleaned, shredded, and added to a batter then frittered (like potato pancakes or latke). Kohlrabi finds its way into slaws, soups, curry dishes, or it can be boiled and mashed with lots of butter, salt and pepper.

Just like the lady in the Himalayas, I’ll pull a kohlrabi from my garden tonight, clean and dice it. I’ll brown some cubes of lamb, add onions, carrots, and the diced kohlrabi. I’ll open a jar of curry sauce that I bought at the local grocery store. When the sauce is warmed and the vegetables are tender, I’ll call the family to the table.

Barb Henny likes Indian cuisine. She has been a gardener in Zone 9 for 40 years.

©2020 Barb Henny. All rights reserved.