Kohlrabi (Brassica oleracea var. gongylodes) belongs to the cabbage family, but the vegetable with the juicy-sweet tubers grows much faster than most of its relatives. If grown in advance in March, kohlrabi can be harvested as early as the end of May or beginning of June, provided the weather is suitable, and it is well cared for. The cabbage plant comes in a wide range of varieties. Kohlrabi is particularly rich in vitamin C and minerals, and its cabbage flavor is rather unobtrusive. Kohlrabi is very easy to grow in a raised bed or vegetable garden. With these tips, you can avoid the biggest mistakes.
Mistake 1: Planting cabbage on cabbage
Although kohlrabi is rather mild in taste, it belongs to the genus of cabbage (Brassica). Like all representatives of this genus, kohlrabi in the garden is susceptible to clubroot. This disease, caused by the pathogen Plasmodiophora brassicae, preferentially attacks cruciferous plants (Brassicaceae). It damages the roots of the plants so severely that they die. Once active, the pathogen survives in the soil for many years and significantly affects the crop. Therefore, where cabbage stood one year, do not plant cabbage, mustard, canola or radish for the next three to four years. Keep these growing breaks for cabbage to prevent clubroot development and infestation of other plants in your vegetable patch. If that’s not possible, replace the soil generously.
Mistake 2: Kohlrabi with woody core
Bigger is not always better. Particularly with vegetables that contain a lot of water, it is true that they taste best when young. If you want to harvest tender, sweet kohlrabi, you should take the tubers out of the bed when they are about the size of a tennis ball. In a suitable location, this is no later than twelve weeks after sowing. If the plants are allowed to continue growing, the tissue will harden over time. The kohlrabi becomes woody and the flesh no longer tastes tender but fibrous.
Mistake 3: Not watering the kohlrabi enough
In principle, kohlrabi is very easy to care for. Especially among children who like to garden, growing the vegetable is popular because it grows so quickly that you can watch. Within eight to twelve weeks after sowing in March or April, the first tubers can already be harvested. One thing is especially important: water your kohlrabi regularly. The plants have a very high water content and need correspondingly abundant and continuous watering. If the water supply dries up for a while and then suddenly resumes, this will cause the tubers to burst open. Especially when temperatures fluctuate, there is a risk that the cabbage will fall dry. A layer of mulch on the bed helps reduce evaporation around the vegetable on hot days. Burst kohlrabi is still edible, but it can become woody and doesn’t look very nice either.