Kohlrabi is an odd-looking member of the turnip family. The bulb grows above ground with leaves poking straight out and up. Some people avoid planting kohlrabi because they’re unsure what the bulb will taste like. But once you taste the mild broccoli and celery root flavor, you’ll wish you planted more.
How to Grow Kohlrabi
Kohlrabi is a cool-season crop that grows in early spring and late fall. Plant as soon as the soil can be worked. There are some varieties that mature in as little as 40 days. To use in cooking, peel the bulbs and eat raw or leave the skin on and cook into soups, stews and stir-fry meals; the leaves can be used like collard greens.
- Like other members of the Brassica family, kohlrabi prefers a rich, loamy soil that drains well. Amend the garden bed with plenty of organic matter, like compost or well-aged manure.
- Start plants indoors or in a cold frame 4 to 6 weeks before you plan to transplant them into the garden. An alternative is to directly sow seeds into the garden or buy transplants from the Garden Center.
- If planting from seed, wait until soil temperatures reach between 60-65 degrees. Plant seeds ¼-inch deep and ½ to 1 inch apart; space rows 12-36 inches apart.
- Once seeds germinate and plants grow to several inches tall, thin the kohlrabi so they’re spaced 4 to 6 inches apart. You can transplant the thinnings to another part of the garden, which will help extend your kohlrabi growing season.
- For the tenderest and tastiest kohlrabi bulbs, focus on rapid growth. After thinning, sidedress with more compost, well-aged manure or a well-balanced dry fertilizer.
- Cultivate lightly, if needed, and avoid damaging the delicate roots that spread just beneath the soil surface. Add a thick layer of organic mulch when plants are several inches tall.
- Place a soaker hose under the mulch and keep the soil moderately moist at all times. Don’t let the soil dry out or the bulbs will become tough instead of tender and sweet.
- Carefully dig up plants while they’re are still young and tender. Harvest bulbs when they reach golf-ball size (1 ½-2 inches in diameter). Waiting for large bulbs will lead to kohlrabi that is stringy and less flavorful.
- Store the bulb separately from the greens and use as soon as possible for the best results.
Plant kohlrabi with these companions:
- Brussels sprouts
Avoid planting near beans, fennel, tomatoes and strawberries
Materials for Success
- Soil thermometer
- Soaker hose
- High-quality compost or well-aged manure
- Balanced fertilizer
- Organic mulch
To learn more about growing kohlrabi or about growing your own edible vegetable garden, contact the pros at Nick’s Garden Center.