Blog

When to Plant Sweet Corn in Ottawa County, MI

Sweet corn is bred for high sugar content in its kernels, which convert to starch rapidly after harvest. Modern supersweet varieties hold their sweetness longer.

Ottawa County, Michigan is in USDA Zone 5b. The average last spring frost is May 9 and the first fall frost is October 9, giving you a growing season of approximately 153 days.

At an elevation of 1,027 feet, Ottawa County receives approximately 41.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Sweet Corn to ensure they mature before fall.

Ottawa County, MI (Zone 5b) Moderate season
153 days
Last Spring Frost May 9
153 growing days
First Fall Frost October 9

Ottawa County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 12
Recommended (50%) ✓ Fits season (48 days to spare)
Transplant: May 9 🍅 Harvest: Jul 11 – Aug 22
Safe Start (90%) ✓ Fits season (44 days to spare)
Transplant: May 29 🍅 Harvest: Jul 31 – Sep 11

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sweet Corn needs ~975 GDD — county provides 1,989 GDD Excellent fit

Sweet Corn Planting Timeline โ€” Ottawa County, MI

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow May 16 May 16 โ€“ Jun 6
Harvest July 18 Jul 18 โ€“ Aug 29

Plant 1" deep ยท 12" apart ยท Rows 36" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Direct Sow
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

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

153 days

Growing Tips for Ottawa County

Plant in blocks of at least 4 rows for wind pollination. Direct sow after soil is warm. Isolate supersweet varieties from other corn types to prevent cross-pollination.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Sweet Corn in Ottawa County, MI?

Ottawa County is in Zone 5b with an average last frost of May 9. Plan your Sweet Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Ottawa County, MI?

Ottawa County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 9 and first fall frost is October 9.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

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