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When to Plant Zucchini in Saginaw County, MI

Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Saginaw County, Michigan is in USDA Zone 5b. The average last spring frost is April 30 and the first fall frost is October 16, giving you a growing season of approximately 169 days.

At an elevation of 748 feet, Saginaw County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Zucchini during the growing season.

Saginaw County, MI (Zone 5b) Moderate season
169 days
Last Spring Frost April 30
169 growing days
First Fall Frost October 16

Saginaw County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Mar 23 Transplant: May 11 🍅 Harvest: Jun 29 – Aug 24
Recommended (50%) ✓ Fits season (50 days to spare)
Start indoors: Mar 26 Transplant: May 14 🍅 Harvest: Jul 2 – Aug 27
Safe Start (90%) ✓ Fits season (48 days to spare)
Start indoors: Apr 11 Transplant: May 30 🍅 Harvest: Jul 18 – Sep 12

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 31 gal / 100 sq ft
Zucchini needs ~801 GDD — county provides 2,577 GDD Excellent fit

Zucchini Planting Timeline โ€” Saginaw County, MI

Zucchini Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 โ€“ Apr 9
Transplant Outdoors May 14 May 14 โ€“ May 28
Direct Sow May 7 May 7 โ€“ May 28
Harvest July 2 Jul 2 โ€“ Aug 27

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 Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

45โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5b

Growing Season

169 days

Growing Tips for Saginaw County

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Zucchini in Saginaw County, MI?

Saginaw County is in Zone 5b with an average last frost of April 30. Plan your Zucchini planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Saginaw County, MI?

Saginaw County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is April 30 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Saginaw County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Saginaw County, MI. Local conditions may vary. Last updated: April 2026.