When to Plant Kabocha in USDA Zone 3b
Your May gardening checklist
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 3b.
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Outdoor sowing time: kabocha
Mark the row. Birds and stray feet both have opinions about unmarked beds.
Looking ahead to June
- Transplants going out: kabocha
- Starting indoors: kabocha
Kabocha is a Japanese winter squash with an exceptionally sweet, dense, chestnut-like flesh and dark green skin. It is a favorite in Asian cuisine for its rich, dry texture.
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.
Kabocha 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 Kabocha planting schedule for that location.
Kabocha Planting Calendar — Zone 3b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 29 | Mar 29 – Apr 12 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 24 | May 24 – Jun 14 |
| Harvest | August 30 | Aug 30 – Sep 27 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| 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
85–100 days
Soil pH
6 – 7.5
Zone Temperature Range
°F to °F average annual minimum
Growing Season
135 days (Zone average)
Planting Specifications
| Planting Depth | 1 inches |
| Plant Spacing | 30 inches apart |
| Row Spacing | 42 inches between rows |
Growing Tips for Kabocha in Zone
Zone has a short growing season (~135 days). Start Kabocha indoors early and use season-extension techniques like row covers and cold frames.
Direct sow after frost or start indoors. Harvest when the skin is hard and dull. The stem should be dry and corky. Stores well for 3-4 months in a cool, dry place.
Companion Planting
Good Companions
Avoid Planting Near
The Gardener's Encyclopedia to Companion Planting
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Saving Kabocha Seeds
Recommended for Your Garden
Start seeds indoors with reusable cell trays and humidity domes.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Keep your garden organized with durable, weather-resistant plant labels.
Related Plants
Kabocha in Other Zones
Kabocha by State
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Kabocha in Zone 3b?
In Zone 3b, plan your Kabocha planting around the average last frost date of May 10. Start seeds indoors around March 29. Direct sow outdoors around May 24. Transplant seedlings around May 31.
Can Kabocha grow in Zone 3b?
Yes, Kabocha can grow well in Zone 3b, hardy in USDA zones 3a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Kabocha (85-100 days to maturity).
When can I harvest Kabocha in Zone 3b?
In Zone 3b, expect to harvest Kabocha from August 30 – September 27. Kabocha takes 85-100 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 Kabocha?
Good companion plants for Kabocha include Corn, Green Beans, Radish. These companions can help with pest control, pollination, and nutrient sharing.
Your Free Printable Garden Planner
A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.