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When to Plant Sunflower in Limestone County, TX

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.

Limestone County, Texas is in USDA Zone 8a. The average last spring frost is March 12 and the first fall frost is November 14, giving you a growing season of approximately 247 days.

At an elevation of 214 feet, Limestone County receives approximately 69.7 inches of rainfall annually with predominantly clay soil. Summer highs average 93ยฐF, providing good warmth for Sunflower during the growing season. Clay soil retains moisture well for Sunflower, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Limestone County, TX (Zone 8a) Long season
247 days
Last Spring Frost March 12
247 growing days
First Fall Frost November 14

Limestone County Soil Profile

Soil Type

Clay

Soil pH

7.1-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (116 days to spare)
Start indoors: Jan 15 Transplant: Mar 19 🍅 Harvest: May 28 – Jul 16
Recommended (50%) ✓ Fits season (114 days to spare)
Start indoors: Jan 22 Transplant: Mar 26 🍅 Harvest: Jun 4 – Jul 23
Safe Start (90%) ✓ Fits season (105 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Jul 1 – Aug 19

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sunflower needs ~1,679 GDD — county provides 4,878 GDD Excellent fit

Sunflower Planting Timeline โ€” Limestone County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 22 Jan 22 โ€“ Feb 5
Transplant Outdoors March 26 Mar 26 โ€“ Apr 9
Direct Sow March 19 Mar 19 โ€“ Apr 9
Harvest June 4 Jun 4 โ€“ Jul 23

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May โ€”
June Harvest
July Harvest
August โ€”
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 8a

Growing Season

247 days

Growing Tips for Limestone 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 Limestone County, TX?

Limestone County is in Zone 8a with an average last frost of March 12. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Limestone County, TX?

Limestone County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 12 and first fall frost is November 14.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Limestone County gardeners in Zone 8a 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 Limestone County, TX. Local conditions may vary. Last updated: April 2026.