When to Plant Sunflower in Hartley 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.
Hartley County, Texas is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 17, giving you a growing season of approximately 177 days.
At an elevation of 4,344 feet, Hartley County receives approximately 46.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sunflower will need more frequent watering and organic matter to retain nutrients.
Hartley County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Sunflower Planting Timeline — Hartley County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 2 | Apr 2 – Apr 16 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Bloom | July 16 | Jul 16 – Oct 22 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| 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 7a
📆 Growing Season
177 days in Hartley County
Growing Tips for Hartley 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
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Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Hartley County, TX?
Hartley County is in Zone 7a with an average last frost of April 23. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hartley County, TX?
Hartley County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 17.
Your Hartley County Garden Planner — Free
A 22-page printable planner built for Hartley County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.