Private: Purple Kohlrabi
Light requirements: Full sun.
Planting: Space 9 to 12 inches apart.
Soil requirements: Kohlrabi needs moist but well-drained, nutrient-rich soil. Amend soil with 4 to 6 inches of compost or other organic matter prior to planting. Soil pH should be 6.5 to 6.8.
Water requirements: Evenly moist soil is the key to tender stems. Apply 1 to 1.5 inches of water per week if it doesn’t rain. Apply mulch to help soil retain moisture.
Frost-fighting plan: Established plants tolerate hard frost (temps below 28º F). Frost sweetens stem flavor. Protect newly planted seedlings from late spring or early fall frosts by covering plants with a frost blanket.
Common issues: Pick stems before bulbs elongate and become tapered; at that point, they’ll have a more bitter flavor. The same pests that like cabbage may attack kohlrabi, but it’s usually less troubled by aphids, root maggots, cabbageworms and other caterpillars. Clubroot and black rot diseases can be a problem. Clubroot can linger in soil for up to 20 years, so don’t plant kohlrabi in beds known to have been afflicted by clubroot in the past.
Harvesting: Harvest kohlrabi stems when they are still young and tender, usually about 2.5 to 4 inches in diameter. Cut them from the base of the plant. Trim the leaves from the stem and save them to cook separately.
Storage: Refrigerate kohlrabi stems in sealed plastic bags in the vegetable drawer. Stems keep for 2 to 3 weeks, but may become woodier as storage time increases.
For more information, visit the Kohlrabi page in our How to Grow section.
- Calories: 48 (raw: 36)
- Carbohydrates: 11g (8g)
- Dietary fiber: 2g (5g)
- Protein: 5g
- Vitamin C: 149% DV
- Vitamin B6: 14%
- Folate: 5%
- Vitamin E: 4%
- Potassium: 16%
- Manganese: 12%
- Copper: 11%
- Magnesium: 8%
This turnip-like bulb has a mild delicate flavor. It adds a sweet crispness when chopped and added to salads and combines well with many flavors when cooked. Whether cooked or raw, kohlrabi packs a punch of vitamin C, fiber, and vitamin B6, along with high doses of the minerals potassium, manganese, and copper. Though not a “root” vegetable like turnips or potatoes, the small flavorful kohlrabi lends itself to any of the same cooked preparations such as steaming, baking, in casseroles or soups.