Kohlrabi Seeds

Kohlrabi is a biennial vegetable grown for its swollen, globe-shaped stem, which sits above ground and sprouts leaves from its surface. If left to its second year, the plant flowers and sets seed in pods much like those of cabbage and broccoli. The seeds are tiny, about 2 mm across, round and reddish-brown to black. They taste peppery and mild, similar to radish or mustard, once sprouted. Seed is sold mostly in garden packets, with purple and green varieties, and also as microgreen and sprouting seed. Stored cool and dry, it remains viable for four years or so. Seed crops cross readily with other forms of Brassica oleracea if grown close together.

Kohlrabi was selected from wild cabbage, Brassica oleracea, a plant of coastal Europe. It is a relatively recent vegetable in the history of cabbages, and it seems to have been developed in northern Europe, not in the ancient world. The name comes from German, Kohl meaning cabbage and Rübe meaning turnip, so the vegetable is literally cabbage-turnip. The botanical group name gongylodes comes from a Greek word meaning rounded, referring to the swollen stem.

A swollen-stemmed cabbage is mentioned in sixteenth-century European herbals, and the first clear records are from Germany and Italy around that time, so kohlrabi appears to have been developed in the Middle Ages or Renaissance. It spread across Europe in the following centuries, becoming a favourite in Germany, Austria, Hungary, and Eastern Europe. By the eighteenth century, it was being grown in England and by German settlers in North America. It was introduced to India in the seventeenth century, probably by Portuguese traders, and became well established in Kashmir, where it is known as monji or knol-khol and is a staple vegetable in the cuisine of the valley. It also became popular in China and Vietnam. Seed production is concentrated in temperate regions, and producers must isolate crops to keep varieties true. Kohlrabi remains a popular garden vegetable because it is quick, hardy and productive, though it is less widely known in some countries.

Seeds are sown for the vegetable, whose bulb is eaten raw in slaws and salads, or cooked in soups, stews, fritters and curries. The leaves can be cooked as greens. Seeds are also sprouted for a few days or grown as microgreens with a mild radish-like flavour, used in sandwiches and salads. Seed saving is practised by gardeners wishing to maintain local varieties. Brassica seed in general can be pressed for oil, but kohlrabi seed is not grown for that purpose.

Kohlrabi, like other cruciferous vegetables, contains glucosinolates and vitamin C, and eating cruciferous vegetables is associated in population studies with healthy diets and possibly lower risk of some diseases, though causation is not proven. The seeds are not eaten in meaningful amounts, but their sprouts also contain glucosinolate-derived compounds. Sprouts are a modest source of vitamins and minerals.