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When to Plant Kabocha in Monroe County, MI

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.

Monroe County, Michigan is in USDA Zone 6a. The average last spring frost is April 27 and the first fall frost is October 17, giving you a growing season of approximately 173 days.

At an elevation of 1,202 feet, Monroe County receives approximately 40.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Kabocha during the growing season.

Monroe County, MI (Zone 6a) Moderate season
173 days
Last Spring Frost April 27
173 growing days
First Fall Frost October 17

Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Start indoors: Mar 20 Transplant: May 8 🍅 Harvest: Aug 7 – Sep 4
Recommended (50%) ✓ Fits season (40 days to spare)
Start indoors: Mar 23 Transplant: May 11 🍅 Harvest: Aug 10 – Sep 7
Safe Start (90%) ✓ Fits season (37 days to spare)
Start indoors: Apr 8 Transplant: May 27 🍅 Harvest: Aug 26 – Sep 23

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.

Soil Compatibility in Monroe County

How your county's soil matches Kabocha's growing requirements.

Soil pH

Your soil pH (5.8โ€“7.2) overlaps with Kabocha's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The silt loam soil in Monroe County is excellent for Kabocha โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Kabocha.

Organic Matter

Organic matter is excellent (4.2%) โ€” Kabocha will thrive.

How to Plant Kabocha

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 484 gal / 100 sq ft

Monthly Watering Guide for Kabocha

Kabocha needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Kabocha Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar โ€” 3.1" 0" โ„๏ธ Dormant
Apr 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
May 4.3" 4.7" 0" โœ… Rainfall sufficient
Jun 4.3" 5.6" 0" โœ… Rainfall sufficient
Jul 4.3" 4.3" 0" โœ… Rainfall sufficient
Aug 4.3" 4.5" 0" โœ… Rainfall sufficient
Sep 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Oct 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Nov โ€” 2.6" 0" โ„๏ธ Dormant
Dec โ€” 2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Monroe County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Kabocha Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Kabocha needs ~1,549 GDD — county provides 2,897 GDD Excellent fit

Kabocha Planting Timeline โ€” Monroe County, MI

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

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

85โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

173 days in Monroe County

Growing Tips for Kabocha in Monroe County

Direct sow Kabocha outdoors after April 27 in Monroe County when soil has warmed and frost danger has passed.

Common pests for Kabocha in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kabocha in Monroe County, MI?

Monroe County is in Zone 6a 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 Monroe County, MI?

Monroe County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 27 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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