Growing Kohlrabi in Zone 3b

Zone 3b has harsh winters and a short growing season. Start Kohlrabi early indoors to maximize your harvest window. Last frost: May 15. First frost: Sep 22.

Planting Calendar

Indoor

Outdoor

Harvest

Apr 3Sep 22

Season: May 15 – Sep 22 (130 days) · Succession: plant every 3 weeks (up to 3x)

Zone3b

Last FrostMay 15

First FrostSep 22

Season Length130 days

Days to Harvest55

SunFull Sun

Frost ToleranceModerate

Spacing6/sqft

When to Plant Kohlrabi in Zone 3b

Start Seeds Indoors: Apr 3

Start Kohlrabi seeds indoors around Apr 3 (6 weeks before last frost). Optimal germination temperature: 65°F. Germinates in 5–10 days.

Transplant Outdoors: Apr 24

Transplant Kohlrabi seedlings outdoors after Apr 24. Wait until soil temperature reaches 45°F. Space plants at 6/sqft. Harden off plants for a week before moving outside.

Harvest: Jun 3

First harvest approximately Jun 3 (~40 days from transplant). Continue harvesting until first frost (Sep 22).

Fall Planting: Jul 28

For a fall harvest, plant Kohlrabi around Jul 28 (8 weeks before first frost).

Kohlrabi in Other Zones

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Frequently Asked Questions

When should I plant Kohlrabi in Zone 3b?

Start Kohlrabi seeds indoors around Apr 3. Transplant outdoors after Apr 24. Expect first harvest around Jun 3.

What is the last frost date for Zone 3b?

The average last spring frost date for Zone 3b is May 15. The first fall frost averages Sep 22, giving a 130-day growing season.

Can I grow Kohlrabi in Zone 3b?

Yes. Kohlrabi needs 55 days to harvest. Zone 3b has a 130-day growing season, which is sufficient. You can plant up to 3 successions.

What is the best month to plant Kohlrabi in Zone 3b?

The best time to start Kohlrabi in Zone 3b is Apr. Begin seeds indoors around Apr 3, then transplant outdoors after the last frost date of May 15.

How long does Kohlrabi take to harvest?

Kohlrabi takes approximately 55 days from planting to harvest. In Zone 3b, expect your first harvest around Jun 3.

Plan Your Kohlrabi Garden

Track Kohlrabi from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

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