Seed to Harvest Growing Guide
How to grow kohlrabi
Grow crisp, mild kohlrabi by planting in cool weather, spacing plants for rapid growth, keeping moisture even, and harvesting the swollen stem before it becomes woody.
Crop family: Brassicaceae
Before you begin
Kohlrabi is an enlarged stem—not a root.
The round edible portion develops above the soil line with leaves emerging like spokes. Rapid, uninterrupted growth produces the mildest flavor and crispest texture.
Build your kohlrabi growing plan
Match the planting window, bed space, seed quantity, and succession dates.
Small sowings every two to three weeks can extend a cool-season harvest.
Kohlrabi at a glance
The path from seed to harvest
Select a milestone to jump to the full instructions.
Stages 1–3
Plant for quick growth in cool weather
Kohlrabi can be direct sown or transplanted. Avoid severe cold, crowding, and a harvest period dominated by summer heat.
Prepare fertile, well-drained soil
Choose full sun and incorporate compost according to soil needs.
- Spring crops can begin 1–2 weeks before the last frost.
- For fall, count back about 50–60 days from the desired harvest.
- Use light shade for young seedlings during hot late-summer starts.
Sow ¼–½ inch deep
Direct sow thinly or start transplants 5–6 weeks before setting out. Keep the seedbed moist through emergence.
Thin to final spacing
Space most plants 4–6 inches apart with rows about 12–18 inches apart.
- Thin when plants have 3–4 true leaves.
- Transplant thinnings promptly or eat them as tender greens.
- Keep the swollen stem above the soil line.
- Use row cover early against flea beetles and caterpillars.
Stage 4
Keep growth fast, cool, and uninterrupted
Shallow roots make kohlrabi sensitive to moisture stress. Consistency is the difference between crisp stems and woody ones.
Water
Supply about 1–2 inches weekly, adjusted for soil and rain. Prevent repeated wet-dry swings.
Feed
Use a soil test. Side-dress lightly about three weeks after thinning if growth is pale or slow.
Mulch
Mulch after establishment to cool soil, conserve moisture, and suppress weeds.
Scout
Check leaf undersides and growing points weekly for pests and disease symptoms.
Growth checkpoints
Know what to watch for.
Harvest quality depends on steady development rather than maximum size.
Thin plants
Create the final 4–6-inch spacing before stems begin enlarging.
Hold moisture steady
Prevent stress while the edible stem expands above the soil.
Begin harvest checks
Early stems are especially mild and crisp.
Harvest promptly
Do not wait for oversized stems to become fibrous.
Stage 5
Diagnose kohlrabi problems early
Open a symptom to compare what you see with the next practical step.
PestCabbage worms and loopersRagged holes, green caterpillars, and dark droppings
Inspect leaf undersides, handpick larvae, use insect netting before butterflies lay eggs, and apply a labeled biological control while caterpillars are small if needed.
PestFlea beetlesTiny black beetles and many round shot-holes on seedlings
Protect young plants with row cover, control brassica weeds, keep plants growing steadily, and rotate the crop. Seedlings are most vulnerable.
PestAphidsColonies beneath leaves, curling, yellowing, and sticky residue
Dislodge colonies with water, protect beneficial insects, remove badly infested leaves, and use insecticidal soap according to its label when necessary.
DiseaseBlack rotYellow V-shaped lesions enter from leaf margins and veins darken
Use clean seed and transplants, avoid working wet plants, remove infected debris, sanitize tools, and rotate away from brassicas. Do not compost badly infected tissue.
Stage 6
Harvest while stems are small and tender
Begin at about 1 inch and finish most harvests by 2–3 inches across unless the variety is specifically bred to remain tender at a larger size.
- Cut: Slice the plant at soil level or pull it and trim the root.
- Trim: Remove leaves for storage; cook the young leaves like kale or cabbage.
- Store: Refrigerate stems in a humid bag for roughly two to three weeks; use leaves within several days.
Choose with purpose
Find the right kohlrabi variety
These verified Shopify links lead to the live kohlrabi collection and specific green, purple, early, and container-friendly options.
Questions gardeners ask
Kohlrabi growing FAQ
Quick answers for planting, quality, harvest, and storage.
Is kohlrabi a root vegetable?
No. The edible globe is a swollen stem that forms above the soil.
When should kohlrabi be planted?
Grow it during cool spring or fall weather. Seed can be planted about 1–2 weeks before the last frost; fall crops are commonly timed 50–60 days before harvest.
Can kohlrabi tolerate frost?
Established plants tolerate light frost, but hard frost can damage young plants and prolonged temperatures below about 45°F may trigger flowering.
How deep should seed be planted?
Sow seed ¼–½ inch deep and keep the surface evenly moist until emergence.
How far apart should plants be?
Most varieties perform well at 4–6 inches apart with rows 12–18 inches apart.
Why is my kohlrabi woody?
Heat, moisture stress, slow growth, or delayed harvest can make stems fibrous. Harvest most varieties by 2–3 inches across.
Why is my kohlrabi flowering?
Extended cold exposure, stress, or an overly mature plant can trigger bolting. Choose suitable timing and avoid holding large transplants too long.
Can the leaves be eaten?
Yes. Young leaves and tender stems can be cooked like kale, collards, or cabbage greens.
Can kohlrabi grow in containers?
Yes. Use a container deep enough for roots, space plants at least 4–6 inches apart, and water consistently.
How much water does kohlrabi need?
About 1–2 inches per week is a useful general target, adjusted for rainfall and soil. Shallow roots require consistent moisture.
How do I know when it is ready?
Harvest when the swollen stem is firm and roughly 2–3 inches across, or according to the variety description.
How should kohlrabi be stored?
Remove leaves and refrigerate the stem in humid storage. Use leaves quickly; stems commonly keep for two to three weeks.
Ready to plant?
Choose kohlrabi for a cool-season harvest.
Compare early green, purple heirloom, hybrid, and container-friendly selections.