When to Plant Sunflower in Clermont 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.
Clermont County, Ohio is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 22, giving you a growing season of approximately 188 days.
At an elevation of 798 feet, Clermont County receives approximately 30.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Sunflower during the growing season.
Clermont County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7
Drainage
Well Drained
Plant Planting Risk Windows
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
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Sunflower Planting Timeline — Clermont County, OH
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 20 | Feb 20 – Mar 6 |
| Transplant Outdoors | May 1 | May 1 – May 15 |
| Direct Sow | April 24 | Apr 24 – May 15 |
| Harvest | July 10 | Jul 10 – Aug 28 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Low — drought tolerant
Days to Maturity
70–100 days
Soil pH
6 – 7.5
USDA Zone
Zone 6a
Growing Season
188 days
Growing Tips for Clermont 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
Level Up Your Garden
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Clermont County, OH?
Clermont County is in Zone 6a with an average last frost of April 17. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clermont County, OH?
Clermont County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 22.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Clermont County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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