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When to Plant Hubbard Squash in Hillsdale County, MI

Hillsdale County, Michigan Zone 5b April

Top priorities for Hillsdale County, Michigan gardeners in April

Your Hillsdale County, Michigan garden is entering a new phase. Here's what's on the schedule for April and why each task matters now.

Avg. last frost April 29
Avg. first frost October 14
Soil temp (4") 44°F
Watering Moderate
Pest pressure Low
Daylight 13.1 hrs
A few tasks this April that'll pay off in May
  • Transplants going out: hubbard squash
  • Direct-sowing: hubbard squash

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Hubbard squash is a large, bumpy-skinned winter squash with dense, sweet, dry flesh ideal for baking and pies. The hard shell allows storage for 6 months or more.

Hillsdale County, Michigan is in USDA Zone 5b. The average last spring frost is April 29 and the first fall frost is October 14, giving you a growing season of approximately 168 days.

At an elevation of 1,173 feet, Hillsdale County receives approximately 41.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Hubbard Squash during the growing season.

Hillsdale County, MI (Zone 5b) Moderate season
168 days
Last Spring Frost April 29
168 growing days
First Fall Frost October 14
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Hillsdale County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Mar 22 Transplant: May 10 🍅 Harvest: Aug 23 – Sep 27
Recommended (50%) ✓ Fits season (14 days to spare)
Start indoors: Mar 25 Transplant: May 13 🍅 Harvest: Aug 26 – Sep 30
Safe Start (90%) ✓ Fits season (8 days to spare)
Start indoors: Apr 11 Transplant: May 30 🍅 Harvest: Sep 12 – Oct 17

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 Hillsdale County

How your county's soil matches Hubbard Squash's growing requirements.

Soil pH

Your soil pH (5.9–6.8) overlaps with Hubbard Squash's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Hubbard Squash

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Hubbard Squash

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

Month Hubbard Squash Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.7" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hillsdale County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Hubbard Squash 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.

Hubbard Squash needs ~1,512 GDD — county provides 2,310 GDD Excellent fit

Hubbard Squash Planting Timeline — Hillsdale County, MI

Hubbard Squash Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors May 13 May 13 – May 27
Direct Sow May 6 May 6 – May 27
Harvest August 26 Aug 26 – Sep 30

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

Month-by-Month Timeline

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

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

168 days in Hillsdale County

Growing Tips for Hubbard Squash in Hillsdale County

Direct sow Hubbard Squash outdoors after April 29 in Hillsdale County when soil has warmed and frost danger has passed.

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

General growing tips

Start seeds indoors in short-season areas. Requires ample space and rich soil. Harvest when the skin is very hard and the color is deep. Cure in the sun before storing.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hubbard Squash in Hillsdale County, MI?

Hillsdale County is in Zone 5b with an average last frost of April 29. Plan your Hubbard Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hillsdale County, MI?

Hillsdale County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is April 29 and first fall frost is October 14.

🌱

Your Hillsdale County Garden Planner — Free

A 24-page printable planner built for Hillsdale 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 Hillsdale County, MI. Local conditions may vary. Last updated: April 2026.

Sources & credits

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