Blog

When to Plant Sunflower in Hardeman 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.

Hardeman County, Texas is in USDA Zone 7b. The average last spring frost is March 30 and the first fall frost is November 7, giving you a growing season of approximately 222 days.

At an elevation of 2,010 feet, Hardeman County receives approximately 47.8 inches of rainfall annually with predominantly loam soil. Summer highs average 89ยฐF, providing good warmth for Sunflower during the growing season.

Hardeman County, TX (Zone 7b) Long season
222 days
Last Spring Frost March 30
222 growing days
First Fall Frost November 7

Hardeman County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Start indoors: Feb 2 Transplant: Apr 6 🍅 Harvest: Jun 15 – Aug 3
Recommended (50%) ✓ Fits season (89 days to spare)
Start indoors: Feb 9 Transplant: Apr 13 🍅 Harvest: Jun 22 – Aug 10
Safe Start (90%) ✓ Fits season (86 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 8 – Aug 26

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 ~1,424 GDD — county provides 3,718 GDD Excellent fit

Sunflower Planting Timeline โ€” Hardeman County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 9 Feb 9 โ€“ Feb 23
Transplant Outdoors April 13 Apr 13 โ€“ Apr 27
Direct Sow April 6 Apr 6 โ€“ Apr 27
Harvest June 22 Jun 22 โ€“ Aug 10

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March โ€”
April Transplant Outdoors Direct Sow
May โ€”
June Harvest
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 7b

Growing Season

222 days

Growing Tips for Hardeman 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 Hardeman County, TX?

Hardeman County is in Zone 7b with an average last frost of March 30. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hardeman County, TX?

Hardeman County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 30 and first fall frost is November 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hardeman County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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 Hardeman County, TX. Local conditions may vary. Last updated: April 2026.