Growing Purple Kohlrabi in Zone 3b
Zone 3b has harsh winters and a short growing season. Start Purple Kohlrabi early indoors to maximize your harvest window. Last frost: May 15. First frost: Sep 22.
Planting Calendar
Season: May 15 – Sep 22 (130 days) · Succession: plant every 3 weeks (up to 3x)
When to Plant Purple Kohlrabi in Zone 3b
Start Seeds Indoors: Apr 3
Start Purple 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 Purple Kohlrabi seedlings outdoors after Apr 24. Wait until soil temperature reaches 45°F. Space plants at 4/sqft (6" apart). 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 Purple Kohlrabi around Jul 28 (8 weeks before first frost).
Purple 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 13bFrequently Asked Questions
When should I plant Purple Kohlrabi in Zone 3b?
Start Purple 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 Purple Kohlrabi in Zone 3b?
Yes. Purple 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 Purple Kohlrabi in Zone 3b?
The best time to start Purple 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 Purple Kohlrabi take to harvest?
Purple Kohlrabi takes approximately 55 days from planting to harvest. In Zone 3b, expect your first harvest around Jun 3.
Plan Your Purple Kohlrabi Garden
Track Purple Kohlrabi from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.
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