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When to plant Squash (Winter) in Roscommon County County,

Roscommon County County's 140-day season only supports one Squash (Winter) planting per year. Sow between May 22 and June 12 for the best chance at full maturity before October 2.

When to Plant Squash (Winter) in Roscommon County, MI

Roscommon County, Michigan Zone 5a June

Your June game plan for Roscommon County, Michigan

Your garden in Roscommon County, Michigan is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 15
Avg. first frost October 2
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 15.3 hrs
  1. Get squash (winter) seeds going inside

    These need a head start before your last frost (May 15). Sow into cells now so you're ready to transplant in a few weeks.

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Winter squash includes butternut, acorn, delicata, and hubbard varieties grown to full maturity with hard rinds for storage. They develop sweet, dense flesh.

Roscommon County, Michigan is in USDA Zone 5a. The average last spring frost is May 15 and the first fall frost is October 2, giving you a growing season of approximately 140 days.

At an elevation of 1,298 feet, Roscommon County receives approximately 36 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Squash (Winter) to ensure they mature before fall.

Roscommon County, MI (Zone 5a) Short season
140 days
Last Spring Frost May 15
140 growing days
First Fall Frost October 2
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Roscommon County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Squash (Winter) Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 5 Transplant: May 24 🍅 Harvest: Aug 16 – Oct 11
Recommended (50%) ✗ May not fit
Start indoors: Apr 10 Transplant: May 29 🍅 Harvest: Aug 21 – Oct 16
Safe Start (90%) ✗ May not fit
Start indoors: Apr 26 Transplant: Jun 14 🍅 Harvest: Sep 6 – Nov 1

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 Roscommon County

How your county's soil matches Squash (Winter)'s growing requirements.

Soil pH

Your soil pH (6.0–6.8) is within Squash (Winter)'s preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Roscommon County is excellent for Squash (Winter) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.2%) — Squash (Winter) will thrive.

How to Plant Squash (Winter)

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

Squash (Winter) Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/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 Squash (Winter)

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

Month Squash (Winter) Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Squash (Winter) 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.

Squash (Winter) needs ~1,225 GDD — county provides 1,715 GDD Excellent fit

Squash (Winter) Planting Timeline — Roscommon County, MI

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 – Apr 24
Transplant Outdoors May 29 May 29 – Jun 12
Direct Sow May 22 May 22 – Jun 12
Harvest August 21 Aug 21 – Oct 16

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

140 days in Roscommon County

Growing Tips for Squash (Winter) in Roscommon County

Direct sow Squash (Winter) outdoors after May 15 in Roscommon County when soil has warmed and frost danger has passed.

Common pests for Squash (Winter) 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 last frost on rich mounds. Allow ample space for sprawling vines. Cure harvested fruits in the sun for 10 days before storing 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 Squash (Winter) in Roscommon County, MI?

Roscommon County is in Zone 5a with an average last frost of May 15. Plan your Squash (Winter) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Roscommon County, MI?

Roscommon County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 15 and first fall frost is October 2.

When should I plant Squash (Winter) in Roscommon County, ?

In Roscommon County, , plant Squash (Winter) after the last frost (around May 15) and before the first frost (around October 2). Best results when soil holds above 50°F.

What growing zone is Roscommon County, for Squash (Winter)?

Roscommon County sits in USDA Zone 5a. Squash (Winter) grows reliably in zones 3a through 11b, so it's a good fit here.

Can Squash (Winter) grow in Roscommon County's climate?

Yes — Squash (Winter) grows well in Roscommon County's temperate climate. Roscommon County averages a 140-day frost-free season, with last frost around May 15 and first frost around October 2.

🌱

Your Roscommon County Garden Planner — Free

A 22-page printable planner built for Roscommon County (Zone 5a). 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 Roscommon County, MI. Local conditions may vary. Last updated: June 2026.

Sources & credits

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