When to Plant Kohlrabi in USDA Zone 3b
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 3b, the average last spring frost is around May 10 and the first fall frost is around September 22, giving you a growing season of approximately 135 days.
Kohlrabi Planting Timeline — Zone 3b
Where Is USDA Zone 3b?
The map below highlights the states that contain Zone 3b. Click any state to see the Kohlrabi planting schedule for that location.
Kohlrabi Planting Calendar — Zone 3b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 29 | Mar 29 – Apr 12 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | May 3 | May 3 – May 24 |
| Fall Sowing | June 30 | Jun 30 – Jul 14 |
| Harvest | June 28 | Jun 28 – Aug 2 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Fall Sowing Harvest |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Free Zone 3b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 3b with start dates, transplant windows, and harvest times.
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
-35°F to -30°F average annual minimum
Growing Season
135 days (Zone 3b average)
Planting Specifications
| Planting Depth | 0.5 inches |
| Plant Spacing | 4 inches apart |
| Row Spacing | 12 inches between rows |
Growing Tips for Zone 3b
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
Level Up Your Garden
Saving Kohlrabi Seeds
Recommended for Your Garden
Full-spectrum LED lights for starting seeds indoors when daylight is limited.
Warm soil for faster germination of heat-loving crops like tomatoes and peppers.
Protect plants from frost, wind, and pests while letting light and water through.
Related Plants
Kohlrabi in Other Zones
Kohlrabi by State
- Alabama
- Alaska
- Alberta
- Arizona
- Arkansas
- British Columbia
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Manitoba
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Brunswick
- New Hampshire
- New Jersey
- New Mexico
- New York
- Newfoundland and Labrador
- North Carolina
- North Dakota
- Northwest Territories
- Nova Scotia
- Nunavut
- Ohio
- Oklahoma
- Ontario
- Oregon
- Pennsylvania
- Prince Edward Island
- Quebec
- Rhode Island
- Saskatchewan
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
- Yukon
Frequently Asked Questions
When should I plant Kohlrabi in Zone 3b?
In Zone 3b, plan your Kohlrabi planting around the average last frost date of May 10. Start seeds indoors around March 29. Direct sow outdoors around May 3. Transplant seedlings around May 10.
Can Kohlrabi grow in Zone 3b?
Yes, Kohlrabi can grow well in Zone 3b, hardy in USDA zones 2a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Kohlrabi (45-65 days to maturity).
When can I harvest Kohlrabi in Zone 3b?
In Zone 3b, expect to harvest Kohlrabi from June 28 – August 2. Kohlrabi takes 45-65 days from planting to harvest.
What is the last frost date for Zone 3b?
The average last spring frost in Zone 3b is around May 10, and the first fall frost is around September 22. This gives a growing season of approximately 135 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 3b, track your crops, and plan your garden season from seed to harvest.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.