When to Plant Sunflower in Upton 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.
Upton County, Texas is in USDA Zone 8b. The average last spring frost is March 20 and the first fall frost is November 12, giving you a growing season of approximately 237 days.
At an elevation of 1,734 feet, Upton County receives approximately 50.9 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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.
Upton County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.8-8.3
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 | — | 3.9" | 0" | ❄️ Dormant |
| Feb | — | 2.5" | 0" | ❄️ Dormant |
| Mar | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Apr | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| May | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jun | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Jul | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 9.8" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 7.7" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Nov | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Upton County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower Planting Timeline — Upton County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | March 6 | Mar 6 – Mar 20 |
| Direct Sow | March 6 | Mar 6 – Mar 27 |
| Bloom | May 29 | May 29 – Oct 16 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| 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
237 days in Upton County
Growing Tips for Upton 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 Upton County, TX?
Upton County is in Zone 8b with an average last frost of March 20. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Upton County, TX?
Upton County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 20 and first fall frost is November 12.
Your Upton County Garden Planner — Free
A 22-page printable planner built for Upton 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.