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When to Plant Sunflower in Rutherford 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.

Rutherford County, Tennessee is in USDA Zone 7a. The average last spring frost is April 12 and the first fall frost is October 24, giving you a growing season of approximately 195 days.

At an elevation of 3,872 feet, Rutherford County receives approximately 44.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Sunflower during the growing season.

Rutherford County, TN (Zone 7a) Moderate season
195 days
Last Spring Frost April 12
195 growing days
First Fall Frost October 24

Rutherford County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (62 days to spare)
Start indoors: Feb 17 Transplant: Apr 21 🍅 Harvest: Jun 30 – Aug 18
Recommended (50%) ✓ Fits season (62 days to spare)
Start indoors: Feb 22 Transplant: Apr 26 🍅 Harvest: Jul 5 – Aug 23
Safe Start (90%) ✓ Fits season (63 days to spare)
Start indoors: Mar 11 Transplant: May 13 🍅 Harvest: Jul 22 – Sep 9

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
Drought risk

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

Sunflower needs ~1,360 GDD — county provides 3,120 GDD Excellent fit

Sunflower Planting Timeline โ€” Rutherford County, TN

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 โ€“ Mar 8
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 7a

Growing Season

195 days

Growing Tips for Rutherford 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 Rutherford County, TN?

Rutherford County is in Zone 7a 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 Rutherford County, TN?

Rutherford County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 12 and first fall frost is October 24.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Rutherford County gardeners in Zone 7a 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 Rutherford County, TN. Local conditions may vary. Last updated: April 2026.