How to Grow Kohlrabi
Kohlrabi At a Glance
Difficulty
Moderate
Category
Vegetable
Sun Exposure
Full Sun, Partial Sun
Frost Tolerance
Frost Hardy
Cold Hardiness
Survives to -7°C
Plant Family
Brassicaceae
Growing Season
Cool Season
Plant Lifecycle
Biennial
How to Start It
★ Recommended for beginners
Kohlrabi handles frost, so sow it about 3 weeks before your last spring frost, and again about 8 weeks before your first fall frost for a crop in the cool of fall. Sow seeds 0.5 cm deep and cover them lightly. They sprout in 5 to 10 days: thin them (pull the extras so each has room) to 15 cm apart.
Kohlrabi is a cabbage cousin grown for its round, crunchy stem that swells just above the soil, with a mild, sweet taste like broccoli stems. It is quick, ready in about 55 days, and is at its best picked young. Heat and dry spells make it tough and woody, so spring and fall crops are the sweetest.
When To Start
First chance to plant
45 Days Before Last Frost
Last chance to plant
60 Days Before First Frost
When should you plant Kohlrabi?
Your planting dates depend on your local climate. Sign up and add your location to unlock personalized dates.
Your Kohlrabi Planting Window
Start planting
May 15, 2026
Last chance
Sep 10, 2026
Your Kohlrabi Calendar
Set your location to turn these into exact dates and reminders.
Sow kohlrabi outdoors now, it handles light frost
3 weeks before your last frost· every year
Pick kohlrabi when the round stem is tennis ball size
55 days after your last frost· every year· optional
Did you water your kohlrabi seedlings today? Keep the top of the soil damp until they are up and growing.
About 1 days after you plant it
Time to thin the kohlrabi seedlings: snip the extras at soil level so each one has room to grow.
About 20 days after you plant it
Your kohlrabi is coming along! Keep the soil evenly moist so the stems grow sweet and tender.
About 28 days after you plant it
Almost ready! Pick kohlrabi when the ball is about the size of a tennis ball, before it turns woody.
About 47 days after you plant it
Picking time may be here: check your kohlrabi.
About 55 days after you plant it
The Journey Ahead
Kohlrabi's Lifecycle
Seedling
Mature Plant
Seed Production
Step 1
Prepare Your Space
0.5 cm
Seeding Depth
15 cm
Plant Spacing
45 cm
Row Spacing
4
Plants / Sq Ft
Vertical Growing
Yes: Tower.
Method: Tower.
Succession Planting
Yes.
Bad Companions
Step 2
Planting & Sprouting
Expect sprouts in 5–10 days
Growing Tips
- 1Grow kohlrabi in full sun, at least 6 hours a day.
- 2Mix plenty of compost into the soil before sowing, since steady growth keeps the stems tender.
- 3Water about twice a week so the soil stays evenly damp, because dry spells make the stems woody and split.
- 4Feed with worm castings or compost tea about 3 weeks after the seedlings come up.
- 5Cover the plants with row cover from the start to keep off flea beetles (tiny black jumping beetles that chew small holes) and the white butterflies whose green caterpillars eat the leaves.
- 6Look under the leaves now and then and pick off any caterpillars by hand.
Seedling Phase
Step 3
Growth & Maturity
~55
Days to Maturity
30 cm
Mature Height
30 cm
Mature Width
Pests to Watch For
Diseases to Watch For
Mature Plant
Step 4
Harvesting
Harvest Window
30 days
When to Pick
Harvest swollen stems when firm
How to Harvest
- 1Kohlrabi is ready when the round stem is 5 to 8 cm across, about the size of a tennis ball or a bit smaller.
- 2Cut the stem just below the ball with a sharp knife, leaving the root in the soil.
- 3Do not wait too long, because big ones turn tough and woody.
- 4Twist off the leaves, which you can cook like kale, and store the trimmed balls in a bag in the fridge for several weeks.
- 5Peel off the tough skin and eat kohlrabi raw in slices or sticks, or roast or stir fry it.
Step 5
Saving Seeds
How to Save Seeds
Kohlrabi makes seed only in its second year, after a winter, so it is a project for keen seed savers. In most of Canada the plants will not live through winter outdoors, so dig a few of the best ones in fall, trim the leaves, keep them in damp sand somewhere cold but above freezing, and replant them in spring. Kohlrabi crosses with cabbage, broccoli, kale and their relatives, so let only one of them flower within about 800 m, and let at least 6 kohlrabi plants flower together, since a single plant does not pollinate itself well. Hybrid F1 seeds will not grow true, so save only from a variety that is not a hybrid. Let the thin pods dry brown on the plant, crush them in a bag, and store the round seeds labelled somewhere cool, dark and dry for about 5 years.
Seed Production
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