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When to Plant Kabocha in Kankakee 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.

Kankakee County, Illinois is in USDA Zone 5a. The average last spring frost is April 20 and the first fall frost is October 14, giving you a growing season of approximately 177 days.

At an elevation of 1,113 feet, Kankakee County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Kabocha during the growing season.

Kankakee County, IL (Zone 5a) Moderate season
177 days
Last Spring Frost April 20
177 growing days
First Fall Frost October 14

Kankakee County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (42 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🍅 Harvest: Jul 29 – Aug 26
Recommended (50%) ✓ Fits season (44 days to spare)
Start indoors: Mar 16 Transplant: May 4 🍅 Harvest: Aug 3 – Aug 31
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: Apr 4 Transplant: May 23 🍅 Harvest: Aug 22 – Sep 19

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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 319 gal / 100 sq ft
Kabocha needs ~1,272 GDD — county provides 2,433 GDD Excellent fit

Kabocha Planting Timeline โ€” Kankakee County, IL

Kabocha Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 โ€“ Mar 30
Transplant Outdoors May 4 May 4 โ€“ May 18
Direct Sow April 27 Apr 27 โ€“ May 18
Harvest August 3 Aug 3 โ€“ Aug 31

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July โ€”
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 5a

Growing Season

177 days

Growing Tips for Kankakee 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 Kankakee County, IL?

Kankakee County is in Zone 5a with an average last frost of April 20. Plan your Kabocha planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Kankakee County, IL?

Kankakee County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 20 and first fall frost is October 14.

๐ŸŒฑ

Plan Your Garden with Confidence

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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 Kankakee County, IL. Local conditions may vary. Last updated: April 2026.