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When to Plant Sunflower in Deaf Smith 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.

Deaf Smith County, Texas is in USDA Zone 7a. The average last spring frost is April 16 and the first fall frost is October 24, giving you a growing season of approximately 191 days.

At an elevation of 4,473 feet, Deaf Smith County receives approximately 49 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96ยฐF, so Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Sunflower will need more frequent watering and organic matter to retain nutrients.

Deaf Smith County, TX (Zone 7a) Moderate season
191 days
Last Spring Frost April 16
191 growing days
First Fall Frost October 24

Deaf Smith County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.7-8.4

Drainage

Well Drained

Monthly Watering Guide for Sunflower

Sunflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sunflower Needs Rainfall You Supplement Action
Jan โ€” 3.5" 0" โ„๏ธ Dormant
Feb โ€” 2.7" 0" โ„๏ธ Dormant
Mar โ€” 2.9" 0" โ„๏ธ Dormant
Apr 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering
May 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Jun 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Jul 4.3" 8.9" 0" โœ… Rainfall sufficient
Aug 4.3" 9.6" 0" โœ… Rainfall sufficient
Sep 4.3" 6.4" 0" โœ… Rainfall sufficient
Oct 4.3" 4.4" 0" โœ… Rainfall sufficient
Nov โ€” 2.6" 0" โ„๏ธ Dormant
Dec โ€” 3.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Deaf Smith County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Sunflower Planting Timeline โ€” Deaf Smith County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 โ€“ Mar 12
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Direct Sow April 23 Apr 23 โ€“ May 14
Harvest July 9 Jul 9 โ€“ Aug 27

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

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Low โ€” drought tolerant

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

191 days in Deaf Smith County

Growing Tips for Deaf Smith 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Deaf Smith County, TX?

Deaf Smith County is in Zone 7a with an average last frost of April 16. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Deaf Smith County, TX?

Deaf Smith County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 16 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

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