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When to plant Squash (Summer) in Mackinac County, MI

Plant Squash (Summer) in Mackinac County, when soil hits 50°F — usually May 19. Continue planting through June 9 for the spring crop.

When to Plant Squash (Summer) in Mackinac County, MI

Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

Mackinac County, Michigan is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 10, giving you a growing season of approximately 151 days.

At an elevation of 1,335 feet, Mackinac County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Squash (Summer) to ensure they mature before fall.

Mackinac County, MI (Zone 5a) Moderate season
151 days
Last Spring Frost May 12
151 growing days
First Fall Frost October 10

Mackinac County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Squash (Summer) Planting Timeline — Mackinac County, MI

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 19 May 19 – Jun 9
Harvest July 14 Jul 14 – Sep 15

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 Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

151 days in Mackinac County

Growing Tips for Mackinac County

Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

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 (Summer) in Mackinac County, MI?

Mackinac County is in Zone 5a with an average last frost of May 12. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mackinac County, MI?

Mackinac County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 10.

When should I plant Squash (Summer) in Mackinac County, MI?

In Mackinac County, MI, plant Squash (Summer) after the last frost (around May 12) and before the first frost (around October 10). Best results when soil holds above 50°F.

What growing zone is Mackinac County, MI for Squash (Summer)?

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

Can Squash (Summer) grow in Mackinac County's climate?

Yes — Squash (Summer) grows well in Mackinac County's temperate climate. Mackinac County averages a 151-day frost-free season, with last frost around May 12 and first frost around October 10.

🌱

Your Mackinac County Garden Planner — Free

A 22-page printable planner built for Mackinac 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 Mackinac County, MI. Local conditions may vary. Last updated: June 2026.

Sources & credits

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