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When to Plant Kabocha in Macoupin County, IL

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.

Macoupin County, Illinois is in USDA Zone 6a. The average last spring frost is April 11 and the first fall frost is October 21, giving you a growing season of approximately 193 days.

At an elevation of 859 feet, Macoupin County receives approximately 30.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Kabocha during the growing season.

Macoupin County, IL (Zone 6a) Moderate season
193 days
Last Spring Frost April 11
193 growing days
First Fall Frost October 21

Macoupin County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (62 days to spare)
Start indoors: Feb 28 Transplant: Apr 18 🍅 Harvest: Jul 18 – Aug 15
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Mar 7 Transplant: Apr 25 🍅 Harvest: Jul 25 – Aug 22
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 16 Transplant: May 4 🍅 Harvest: Aug 3 – Aug 31

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 563 gal / 100 sq ft
Kabocha needs ~1,619 GDD — county provides 3,377 GDD Excellent fit

Kabocha Planting Timeline โ€” Macoupin County, IL

Kabocha Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 โ€“ Mar 21
Transplant Outdoors April 25 Apr 25 โ€“ May 9
Direct Sow April 18 Apr 18 โ€“ May 9
Harvest July 25 Jul 25 โ€“ Aug 22

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

85โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6a

Growing Season

193 days

Growing Tips for Macoupin County

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

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Kabocha in Macoupin County, IL?

Macoupin County is in Zone 6a with an average last frost of April 11. Plan your Kabocha planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Macoupin County, IL?

Macoupin County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 11 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Macoupin County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Macoupin County, IL. Local conditions may vary. Last updated: April 2026.