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When to Plant Sunflower in Midland County, MI

Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Midland County, Michigan is in USDA Zone 5b. The average last spring frost is May 4 and the first fall frost is October 13, giving you a growing season of approximately 162 days.

At an elevation of 810 feet, Midland County receives approximately 37.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Sunflower during the growing season.

Midland County, MI (Zone 5b) Moderate season
162 days
Last Spring Frost May 4
162 growing days
First Fall Frost October 13

Midland County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Mar 3 Transplant: May 12 🍅 Harvest: Jul 21 – Sep 8
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 9 Transplant: May 18 🍅 Harvest: Jul 27 – Sep 14
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Mar 23 Transplant: Jun 1 🍅 Harvest: Aug 10 – Sep 28

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
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sunflower needs ~1,169 GDD — county provides 2,227 GDD Excellent fit

Sunflower Planting Timeline โ€” Midland County, MI

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 โ€“ Mar 23
Transplant Outdoors May 18 May 18 โ€“ Jun 1
Direct Sow May 11 May 11 โ€“ Jun 1
Harvest July 27 Jul 27 โ€“ Sep 14

Plant 1" deep ยท 18" apart ยท Rows 30" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5b

Growing Season

162 days

Growing Tips for Midland County

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunflower in Midland County, MI?

Midland County is in Zone 5b with an average last frost of May 4. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Midland County, MI?

Midland County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 4 and first fall frost is October 13.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Midland 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 Midland County, MI. Local conditions may vary. Last updated: April 2026.