Growing and Saving the Seed Of Kohlrabi
Kohlrabi is translated from German as “cabbage turnip,” and it is indeed a cabbage relative that was developed for its large, succulent stem. Kohlrabi is a popular fall crop in northern Europe. Plants thrive in cool weather and develop an especially sweet flavor when exposed to a light frost. Also popular in India, kohlrabi is the most commonly eaten vegetable in the province of Kashmir.
While kohlrabi is relatively obscure in the United States, it has been grown here since the early 1800s. Its history in Europe dates back to the 1500s.
- Many culinary uses
- Sow seeds indoors 4-6 weeks before last frost.
- Sow seeds ¼ inch deep.
- Seeds germinate in 6-9 days.
- Ideal germination temperature is 45-80 F.
- Set seedlings outside for two weeks before planting to harden off. For a fall crop, sow seeds 8-10 weeks before first frost.
- Kohlrabi needs full sunlight and fertile, well-drained soil.
- Inconsistent watering will cause cracking of the bulbous stems.
- Use drip irrigation to water evenly.
- Plants are shallow rooted, so avoid cultivating too closely to the plants.
- A thick layer of mulch will help to retain moisture and suppress weeds.
Kohlrabi stands up to disease and pests better than most other cabbage relatives.
Still, fungus can be an issue, so be sure to rotate crops, provide good airflow, and avoid overhead irrigation.
Cabbage loopers can be picked off by hand, or you can treat plants with Bt or with diatomaceous earth.
- Like its cabbage cousin, kohlrabi is a biennial and must be overwintered to produce seeds.
- Kohlrabi is hardy down to 20 F. Those in areas with mild winters should have no issue keeping plants alive over winter.
- In cooler regions, kohlrabi must be dug up and overwintered in sand in the root cellar. Kohlrabi stored this way should not be allowed to dry up and may need light watering while in storage.
Replant them after the last frost and allow them to go to seed.
Pick the seed pods after they are thoroughly dried and place them in a cloth bag. You will need to use a hammer or step on the stubborn pods to free the seeds.
Separate seeds from chaff (leaf, pod and stem trash) and store in glass jars in the refrigerator.