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When to Plant Kabocha in Greene County, IA

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.

Greene County, Iowa is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 5, giving you a growing season of approximately 161 days.

At an elevation of 1,292 feet, Greene County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Kabocha during the growing season.

Greene County, IA (Zone 5a) Moderate season
161 days
Last Spring Frost April 27
161 growing days
First Fall Frost October 5

Greene County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Mar 18 Transplant: May 6 🍅 Harvest: Aug 5 – Sep 2
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Mar 23 Transplant: May 11 🍅 Harvest: Aug 10 – Sep 7
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Apr 6 Transplant: May 25 🍅 Harvest: Aug 24 – Sep 21

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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 173 gal / 100 sq ft
Kabocha needs ~1,341 GDD — county provides 2,334 GDD Excellent fit

Kabocha Planting Timeline โ€” Greene County, IA

Kabocha Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 โ€“ Apr 6
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow May 4 May 4 โ€“ May 25
Harvest August 10 Aug 10 โ€“ Sep 7

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

Month-by-Month Timeline

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

161 days

Growing Tips for Greene 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 Greene County, IA?

Greene County is in Zone 5a with an average last frost of April 27. Plan your Kabocha planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Greene County, IA?

Greene County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Greene County gardeners in Zone 5a 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 Greene County, IA. Local conditions may vary. Last updated: April 2026.