How to Grow Kohlrabi

Kohlrabi

Brassica oleracea var. gongylodes

vegetable

Kohlrabi is a cool-season cruciferous vegetable that produces a swollen, bulbous stem above ground with leaves extending from it. Often called a "space cabbage," it has a mild, slightly sweet flavor similar to cabbage stem or turnip and is highly nutritious. The edible bulb can be harvested when small and tender or left to grow larger depending on variety.

Looking for a specific variety?

Kolibri Kossak Quickstar Knievel Kolibri Purple Ysero

Growing Conditions

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Sun: Full sun, 6-8 hours daily minimum; tolerates partial shade in hot climates

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Water: Consistent, even moisture; 1-1.5 inches per week. Keep soil uniformly moist to prevent splitting and woody texture. Mulch to retain moisture and regulate soil temperature.

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Spacing: 6-8 inches

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Days to maturity: 45-60

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Planting depth: 0.25 inches (seeds); transplants at soil level keeping the bulb just above soil surface

Soil

Type: Well-draining, fertile loamy soil rich in organic matter

pH: 6.0-7.5

Amendments:

Compost aged manure balanced fertilizer (10-10-10) lime if soil is too acidic

Growing Zones

Find your zone →

Thrives in zones 3-9; grows best in cool seasons, can be grown spring or fall in most regions

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

Growth Stages

Seedling

2-3 weeks

Tiny cotyledons emerge, followed by true leaves that look similar to cabbage. Plants are delicate and vulnerable to pests.

Keep soil consistently moist. Provide bright light if indoors. Thin seedlings to prevent crowding when first true leaves appear. Start indoors 4-6 weeks before transplant date.

Early Vegetative

2-3 weeks

Leaves develop steadily, forming a small rosette. The stem base begins to thicken slightly but is not yet noticeably bulbous.

Transplant when 3-4 true leaves present. Harden off seedlings before planting outdoors. Water consistently and apply light mulch. Begin pest monitoring.

Bulb Development

2-3 weeks

The stem swells rapidly to form the characteristic bulbous shape. Leaves continue expanding around the bulb. This is the most critical growth period.

Maintain consistent moisture to prevent splitting and woodiness. Keep bulb mostly above soil surface for even development. Side-dress with compost or balanced fertilizer mid-stage. Monitor for cabbage worms and flea beetles intensively.

Harvest-Ready

5-7 days (harvest window)

Bulbs reach desired size (2-3 inches diameter for tender texture, up to 6 inches for larger varieties). Surface may feel slightly woody if left too long.

Begin harvesting at 2 inches for best tenderness, or wait for 4-6 inches depending on preference. Harvest from bottom by cutting the bulb with a knife, leaving leaves attached. Do not wait too long past peak maturity or quality declines.

Companion Planting

Plan your garden →

Plant with:

Beets Carrots Celery Cucumber Dill Lettuce Onions Potatoes Spinach Thyme

Avoid planting near:

Fennel Other brassicas (cabbage, broccoli, kale) in same bed to reduce pest and disease buildup Pole beans Strawberries Tomatoes

Common Pests

Handpick larvae; use floating row covers; apply Bacillus thuringiensis (Bt); plant trap crops like nasturtiums
Use row covers on young plants; spray neem oil or kaolin clay; dust with food-grade diatomaceous earth; remove weeds nearby
Strong water spray to dislodge; insecticidal soap; neem oil; encourage natural predators like ladybugs
Improve drainage and soil pH to 6.8+; rotate crops; remove infected plants; do not replant brassicas in same spot for 3-4 years
Yellow sticky traps; neem oil; insecticidal soap; vacuum pests with hand-held device

Uses

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Fresh eating and cooking

Culinary

Raw kohlrabi bulbs are crunchy and mildly sweet, excellent sliced in salads, stir-fries, or roasted. The leaves are also edible and nutritious, with a flavor similar to kale. [source]

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Nutritional powerhouse

Culinary

High in vitamin C, fiber, potassium, and manganese. Low in calories and carbohydrates, making it suitable for various diets. [source]

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Antioxidant and anti-inflammatory properties

Medicinal

Contains glucosinolates and other phytonutrients associated with reduced inflammation and potential cancer-protective effects, common to brassicas. [source]

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Long storage potential

Household

Kohlrabi keeps well in cool, humid storage (refrigerator or root cellar) for 3-4 weeks, making it excellent for food preservation and extended pantry use. [source]

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Pollinator and predator plant

Wildlife

Flowering kohlrabi left to bolt provides nectar and pollen for bees and beneficial insects, supporting garden ecosystem health. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Harvest when bulbs are 2-3 inches in diameter for maximum tenderness and mild flavor, or up to 4-6 inches for larger varieties. Use a sharp knife to cut the bulb just below the swollen portion, leaving 1-2 inches of stem. Harvest in morning when plants are cool. Leave the plant in ground and continue harvesting leaves, or pull entire plant. Young bulbs can be left in soil 2-3 weeks at peak maturity in cool weather; they deteriorate faster in heat. For fall crops, time planting so harvest occurs before first frost (kohlrabi tolerates light frost but quality declines in freezing temperatures).

Fun Facts

🌱 Kohlrabi's name comes from German: 'Kohl' (cabbage) + 'Rabi' (turnip), reflecting its hybrid appearance. It was developed in northern Europe in the 15th century.
🌱 The bulb grows above ground making it easy to harvest and monitor, unlike root crops. In ideal growing conditions, kohlrabi can double in size within 1-2 weeks.
🌱 Both the bulb and leaves are completely edible and nutritious—nothing goes to waste. Smaller kohlrabi bulbs (2-3 inches) are tender and mild, while larger specimens can develop a woody, cabbage-like texture if overmatured.

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