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When to Plant Sunflower in Huron County, OH

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.

Huron County, Ohio is in USDA Zone 5b. The average last spring frost is April 27 and the first fall frost is October 18, giving you a growing season of approximately 174 days.

At an elevation of 1,242 feet, Huron County receives approximately 32.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Sunflower during the growing season.

Huron County, OH (Zone 5b) Moderate season
174 days
Last Spring Frost April 27
174 growing days
First Fall Frost October 18

Huron County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (39 days to spare)
Start indoors: Feb 26 Transplant: May 7 🍅 Harvest: Jul 16 – Sep 3
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Mar 2 Transplant: May 11 🍅 Harvest: Jul 20 – Sep 7
Safe Start (90%) ✓ Fits season (38 days to spare)
Start indoors: Mar 18 Transplant: May 27 🍅 Harvest: Aug 5 – Sep 23

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
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sunflower needs ~1,296 GDD — county provides 2,653 GDD Excellent fit

Sunflower Planting Timeline โ€” Huron County, OH

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 โ€“ Mar 16
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow May 4 May 4 โ€“ May 25
Harvest July 20 Jul 20 โ€“ Sep 7

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 โ€”
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

174 days

Growing Tips for Huron 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 Huron County, OH?

Huron County is in Zone 5b with an average last frost of April 27. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Huron County, OH?

Huron County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 27 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

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