When can I plant kohlrabi outside?

Direct sow or transplant 4 weeks before your last spring frost.

How long until kohlrabi is ready to harvest?

45-60 days. Bulb is 2-3 inches across (tennis ball size), still tender; larger bulbs become woody

When to Plant Kohlrabi

Brassica oleracea var. gongylodes

vegetableZones 3–10beginner

Unusual cool-season vegetable forming a swollen stem bulb above ground. Mild, sweet flavor similar to broccoli stems. Quick to mature and fun to grow.

Planting calendar

Direct sow / transplant

4 weeks before your last spring frost.

Fall planting

8 weeks before your first fall frost.

Fast-growing; succession plant every 2-3 weeks for continuous harvest

Spacing & harvest

Plant spacing: 6-8 inches
Row spacing: 12-18 inches
Days to harvest: 45-60 days
Ready when: Bulb is 2-3 inches across (tennis ball size), still tender; larger bulbs become woody

Companion planting

Plant near

Onion — Deters common brassica pests
Beet — Good space companions with different root depths

Keep away from

Bell Pepper — Stunts pepper growth
Strawberry — Inhibits brassica growth

Get kohlrabi planting dates for your exact zone

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Sources: Purdue University Turfgrass Science: Use Growing Degree Days to Better Time Your Applications · University of Missouri Extension: Cool-Season Grasses: Lawn Maintenance Calendar · University of Minnesota Extension: Pre-emergent Herbicides for Crabgrass Control in Lawns