Kohlrabi

Cousin to cabbages and Brussels sprouts, kohlrabi is an easy addition to your garden.

Fresh green whole Kohlrabi (Jonathunder) GFDL 1.2

All parts of the kohlrabi plant are edible. Sweeter and more mild than either cabbage or turnips, kohlrabi (Brassica oleracea) is a highly nutritious vegetable, with plenty of fiber and vitamins.

Kohlrabi description

The swollen bulb-shaped portion of kohlrabi is actually a modified stem. The outer skin can be pale green or purple, depending on the cultivar. The blue-green leaves look striking. This biennial plant makes an attractive addition to your garden, as well as your dinner table. ​

Basket of kohlrabi (Secretlondon CC BY-SA 3.0)

How to grow kohlrabi

Kohlrabi is generally a cool season crop. It needs full sun and good drainage. Kohlrabi plants prefer a soil pH of 5.5 to 6.8. If your soil is more alkaline than that, acidification may be a good idea.

Here in San Jose, California, kohlrabi plants can be started in February and March, and then again in September and October. These are heavy feeders, so top dressing with aged compost can ensure they have access to all the nutrients they need. Mulching around plants is also helpful. Regular irrigation will prevent your kohlrabi from becoming woody textured.

If you are starting with seedlings, put them in the ground so that the first set of leaves is just above the soil line. If growing seeds, cover seeds with 1/4” of soil and space plants 9-12” apart. It takes 45 to 60 days for kohlrabi to reach maturity.

Kohlrabi pests and diseases

Cabbage loopers, cutworms, and imported cabbageworms are the most common pests of kohlrabi. These plants are susceptible to cabbage yellows, clubroot, and downy mildews.

Give kohlrabi a try and see how productive these plants can be!