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When to Plant Kabocha in Houghton County, MI

Houghton County, Michigan Zone 5b May

Your May planting checklist for Houghton County, Michigan

We've pulled the most time-sensitive tasks for Houghton County, Michigan this May and put them front and centre. Tackle them in order.

Avg. last frost May 19
Avg. first frost October 2
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.9 hrs
  1. Put kabocha seeds straight in the ground

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

June prep starts now
  • Transplants going out: kabocha
  • Starting indoors: kabocha

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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.

Houghton County, Michigan is in USDA Zone 5b. The average last spring frost is May 19 and the first fall frost is October 2, giving you a growing season of approximately 136 days.

At an elevation of 956 feet, Houghton County receives approximately 34.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Kabocha to ensure they mature before fall.

Houghton County, MI (Zone 5b) Short season
136 days
Last Spring Frost May 19
136 growing days
First Fall Frost October 2
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Houghton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (3 days to spare)
Start indoors: Apr 10 Transplant: May 29 🍅 Harvest: Aug 28 – Sep 25
Recommended (50%) ✓ Fits season (3 days to spare)
Start indoors: Apr 14 Transplant: Jun 2 🍅 Harvest: Sep 1 – Sep 29
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: Apr 28 Transplant: Jun 16 🍅 Harvest: Sep 15 – Oct 13

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 Houghton County

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

Soil pH

Your soil pH (5.9–7.2) overlaps with Kabocha's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Houghton County is excellent for Kabocha — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Kabocha.

How to Plant Kabocha

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.3" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 3.6" 0" ❄️ Dormant
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Houghton County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~1,202 GDD — county provides 1,768 GDD Excellent fit

Kabocha Planting Timeline — Houghton County, MI

Kabocha Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest September 1 Sep 1 – Sep 29

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

85–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

136 days in Houghton County

Growing Tips for Kabocha in Houghton County

Direct sow Kabocha outdoors after May 19 in Houghton 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 Houghton County, MI?

Houghton County is in Zone 5b with an average last frost of May 19. Plan your Kabocha planting based on this frost date — see the calendar above for exact timing.

What planting zone is Houghton County, MI?

Houghton County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 19 and first fall frost is October 2.

🌱

Your Houghton County Garden Planner — Free

A 24-page printable planner built for Houghton County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Houghton County, MI. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.