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When to Plant Kohlrabi in USDA Zone 6b

Kohlrabi is an unusual brassica that forms a swollen stem above ground with a mild, sweet turnip-like flavor. Both the bulb and tender leaves are edible.

In Zone 6b, the average last spring frost is around April 3 and the first fall frost is around October 25, giving you a growing season of approximately 205 days.

Zone 6b Long season
205 days
Last Spring Frost April 3
205 growing days
First Fall Frost October 25

Kohlrabi Planting Timeline — Zone 6b

Where Is USDA Zone 6b?

The map below highlights the states that contain Zone 6b. Click any state to see the Kohlrabi planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Kohlrabi Planting Calendar — Zone 6b

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Fall Sowing August 16 Aug 16 – Aug 30
Harvest May 22 May 22 – Jun 26

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July
August Fall Sowing
September
October
November
December

Free Zone 6b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 6b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate — regular watering

Days to Maturity

45–65 days

Soil pH

6 – 7.5

Zone Temperature Range

-5°F to 0°F average annual minimum

Growing Season

205 days (Zone 6b average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing4 inches apart
Row Spacing12 inches between rows

Growing Tips for Zone 6b

Direct sow in spring or fall. Harvest when bulbs are 2-3 inches in diameter for best texture and flavor. Larger bulbs may become woody and fibrous.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Level Up Your Garden

Saving Kohlrabi Seeds

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Start seeds indoors with reusable cell trays and humidity domes.

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Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

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Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

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Frequently Asked Questions

When should I plant Kohlrabi in Zone 6b?

In Zone 6b, plan your Kohlrabi planting around the average last frost date of April 3. Start seeds indoors around February 27. Direct sow outdoors around March 20. Transplant seedlings around April 3.

Can Kohlrabi grow in Zone 6b?

Yes, Kohlrabi can grow well in Zone 6b, hardy in USDA zones 2a through 11b. Zone 6b has a growing season of approximately 205 days, which is sufficient for Kohlrabi (45-65 days to maturity).

When can I harvest Kohlrabi in Zone 6b?

In Zone 6b, expect to harvest Kohlrabi from May 22 – June 26. Kohlrabi takes 45-65 days from planting to harvest.

What is the last frost date for Zone 6b?

The average last spring frost in Zone 6b is around April 3, and the first fall frost is around October 25. This gives a growing season of approximately 205 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Kohlrabi?

Good companion plants for Kohlrabi include Beets, Cucumber, Onion. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 6b, track your crops, and plan your garden season from seed to harvest.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.