When should I plant Purple Kohlrabi in Zone 3a?

Start Purple Kohlrabi seeds indoors around Apr 10. Transplant outdoors after May 1. Expect first harvest around Jun 10.

What is the last frost date for Zone 3a?

The average last spring frost date for Zone 3a is May 22. The first fall frost averages Sep 12, giving a 113-day growing season.

Can I grow Purple Kohlrabi in Zone 3a?

Yes. Purple Kohlrabi needs 55 days to harvest. Zone 3a has a 113-day growing season, which is sufficient. You can plant up to 2 successions.

Growing Purple Kohlrabi in Zone 3a

Zone 3a has harsh winters and a short growing season. Start Purple Kohlrabi early indoors to maximize your harvest window. Last frost: May 22. First frost: Sep 12.

Planting Calendar

Indoor

Outdoor

Harvest

Apr 10Sep 12

Season: May 22 – Sep 12 (113 days) · Succession: plant every 3 weeks (up to 2x)

Zone3a

Last FrostMay 22

First FrostSep 12

Season Length113 days

Days to Harvest55

SunFull Sun

Frost ToleranceModerate

Spacing4/sqft (6" apart)

When to Plant Purple Kohlrabi in Zone 3a

Start Seeds Indoors: Apr 10

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

Transplant Outdoors: May 1

Transplant Purple Kohlrabi seedlings outdoors after May 1. 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 10

First harvest approximately Jun 10 (~40 days from transplant). Continue harvesting until first frost (Sep 12).

Fall Planting: Jul 18

For a fall harvest, plant Purple Kohlrabi around Jul 18 (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 13b

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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