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When to Plant Sunflower in Limestone County, TX

Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.

Limestone County, Texas is in USDA Zone 8b. 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 93°F, 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.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Limestone County, TX (Zone 8b) 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

6.0-7.0

Drainage

Well Drained

Sunflower Planting Timeline — Limestone County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors February 26 Feb 26 – Mar 12
Direct Sow February 26 Feb 26 – Mar 19
Bloom May 21 May 21 – Oct 8

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March Start Indoors Transplant Outdoors Direct Sow
April
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 8b

📆 Growing Season

247 days in Limestone County

Growing Tips for Limestone County

Direct-sow 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Limestone County, TX?

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

What planting zone is Limestone County, TX?

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

🌱

Your Limestone County Garden Planner — Free

A 22-page printable planner built for Limestone County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Limestone County, TX. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.