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When to Plant Kohlrabi in USDA Zone 5b

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 5b, the average last spring frost is around April 18 and the first fall frost is around October 13, giving you a growing season of approximately 178 days.

Zone 5b Moderate season
178 days
Last Spring Frost April 18
178 growing days
First Fall Frost October 13

Kohlrabi Planting Timeline — Zone 5b

Where Is USDA Zone 5b?

The map below highlights the states that contain Zone 5b. 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 5b

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Fall Sowing August 4 Aug 4 – Aug 18
Harvest June 6 Jun 6 – Jul 11

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

Month-by-Month Timeline

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

Free Zone 5b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 5b 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

-15°F to -10°F average annual minimum

Growing Season

178 days (Zone 5b average)

Planting Specifications

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

Succession Planting Kohlrabi in Zone 5b

4
successive plantings in Zone 5b's ~178-day season

Sow every 5.1 weeks for continuous harvest throughout the season.

Growing Tips for Kohlrabi in Zone 5b

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

Recommended for Your Garden

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Seed Starting Trays $8-20

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 5b?

In Zone 5b, plan your Kohlrabi planting around the average last frost date of April 18. Start seeds indoors around March 14. Direct sow outdoors around April 4. Transplant seedlings around April 18.

Can Kohlrabi grow in Zone 5b?

Yes, Kohlrabi can grow well in Zone 5b, hardy in USDA zones 2a through 11b. Zone 5b has a growing season of approximately 178 days, which is sufficient for Kohlrabi (45-65 days to maturity).

When can I harvest Kohlrabi in Zone 5b?

In Zone 5b, expect to harvest Kohlrabi from June 6 – July 11. Kohlrabi takes 45-65 days from planting to harvest.

What is the last frost date for Zone 5b?

The average last spring frost in Zone 5b is around April 18, and the first fall frost is around October 13. This gives a growing season of approximately 178 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 5b, track your crops, and plan your garden season from seed to harvest.

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Free download. Plan your entire garden season in minutes.

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.