What about it?
Kohlrabi is a member of the mustard family and its close relatives are the cole crops, which include cabbage, cauliflower, broccoli, Brussels sprouts, and kale. Cole translates to 'stem cabbage; and that is exactly what the edible portion of kohlrabi is, an enlarged stem. It is available in light green and red-purple varieties.
What is it used for?
Kohlrabi plants produce a swollen stem with a turnip- or broccoli- like flavor that can be steamed or eaten raw in salads.
Where does it grow? How do we grow it?
Since kohlrabi is a quick-growing plant, it's a good candidate for direct seeding in the garden. The plants need generous nutrients and water. Unlike other crops of the mustard family, kohlrabi's best growing temperature range is 60 to 80 degrees F.
What are its primary problems?
Kohlrabi is the most cold sensitive of the Brassicas. Likewise, prolonged hot weather will cause the enlarged stems to become woody as the plant struggles to provide sap to its foliage to prevent wilting. It is also much less tolerant of transplanting than other cole crops.
Diseases commonly found among kohlrabi plants include black leg, black rot, clubroot, downy mildew, and fusarium yellows. Insects found on the kohlrabi include flea beetle, harlequin bug, maggot, imported cabbage worm, and cabbage looper.
How do we harvest and store it?
Plants should be ready to harvest 50 to 70 days after planting, when the enlarged stem portion is about 2 inches in diameter. Do not let kohlrabi plants languish in the field. They become very tough or hard. The true measure for harvest is tenderness, but this can be determined only by cutting into the stem. For best quality, harvest when the bulbs are young and immature: as small as 1 1/2 inches and no larger than 3 inches.
Harvest kohlrabi by slicing through the stem an inch below the enlarged stem, then remove the leaves.
Kohlrabi stems keep best at cold temperatures. They will keep for 3 to 4 weeks when stored in a plastic bag in a refrigerator.
© Copyright, Department of Horticulture, Cornell University.