When to Plant Sunflower in Mills 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.
Mills County, Texas is in USDA Zone 8b. The average last spring frost is March 23 and the first fall frost is November 12, giving you a growing season of approximately 234 days.
At an elevation of 4,208 feet, Mills County receives approximately 61.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Sunflower during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.
Mills County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.6
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 2.4" | 0" | ❄️ Dormant |
| Mar | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Apr | 4.3" | 6.2" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 10.5" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 9.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 7.5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 7" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Nov | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Mills County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower Planting Timeline — Mills County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | March 9 | Mar 9 – Mar 23 |
| Direct Sow | March 9 | Mar 9 – Mar 30 |
| Bloom | June 1 | Jun 1 – Oct 19 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | — |
| May | — |
| 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
234 days in Mills County
Growing Tips for Mills 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
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Mills County, TX?
Mills County is in Zone 8b with an average last frost of March 23. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mills County, TX?
Mills County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 23 and first fall frost is November 12.
Your Mills County Garden Planner — Free
A 22-page printable planner built for Mills 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.