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When to Plant Sunflower in Clay County, TN

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.

Clay County, Tennessee is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 27, giving you a growing season of approximately 198 days.

At an elevation of 1,418 feet, Clay County receives approximately 42.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Sunflower during the growing season.

Clay County, TN (Zone 6b) Moderate season
198 days
Last Spring Frost April 12
198 growing days
First Fall Frost October 27

Clay County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Feb 10 Transplant: Apr 21 🍅 Harvest: Jun 30 – Aug 18
Recommended (50%) ✓ Fits season (65 days to spare)
Start indoors: Feb 15 Transplant: Apr 26 🍅 Harvest: Jul 5 – Aug 23
Safe Start (90%) ✓ Fits season (67 days to spare)
Start indoors: Feb 28 Transplant: May 9 🍅 Harvest: Jul 18 – Sep 5

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
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Sunflower needs ~1,232 GDD — county provides 2,871 GDD Excellent fit

Sunflower Planting Timeline โ€” Clay County, TN

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 โ€“ Mar 1
Transplant Outdoors April 26 Apr 26 โ€“ May 10
Direct Sow April 19 Apr 19 โ€“ May 10
Harvest July 5 Jul 5 โ€“ Aug 23

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
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

Low โ€” drought tolerant

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

198 days

Growing Tips for Clay 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 Clay County, TN?

Clay County is in Zone 6b with an average last frost of April 12. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clay County, TN?

Clay County, Tennessee is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clay County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clay County, TN. Local conditions may vary. Last updated: April 2026.