When to Plant Sunflower in McMullen County, TX
May to-do list for McMullen County, Texas
Here's what deserves your attention in McMullen County, Texas this month. Everything below is tailored to Zone 9b and timed around your local frost dates.
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It's harvest week for sunflower
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Get ahead of June
- First harvests: sunflower
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.
McMullen County, Texas is in USDA Zone 9b. The average last spring frost is February 20 and the first fall frost is December 1, giving you a growing season of approximately 284 days.
At an elevation of 3,741 feet, McMullen County receives approximately 58 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Sunflower may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.
McMullen County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.2
Drainage
Well Drained
Plant Planting Risk Windows
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.
Soil Compatibility in McMullen County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (6.8–7.2) is within Sunflower's preferred range (6.0–7.5).
Soil Texture
The loam soil in McMullen County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Sunflower.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Aug 23 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Sunflower
Sunflower needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Sunflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2" | 0.2" | 💧 Light watering |
| Mar | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 9.4" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 9.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 7.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 6.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Dec | 2.2" | 1.3" | 0.9" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in McMullen County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Sunflower Planting Timeline — McMullen County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 9 | Jan 9 – Jan 23 |
| Transplant Outdoors | February 27 | Feb 27 – Mar 13 |
| Direct Sow | February 20 | Feb 20 – Mar 13 |
| Harvest | May 8 | May 8 – Jun 26 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
284 days in McMullen County
Growing Tips for Sunflower in McMullen County
Direct sow Sunflower outdoors after February 20 in McMullen County when soil has warmed and frost danger has passed.
With summer highs reaching 103°F in McMullen County, provide afternoon shade for Sunflower and water deeply in the morning.
Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in McMullen County, TX?
McMullen County is in Zone 9b with an average last frost of February 20. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is McMullen County, TX?
McMullen County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 20 and first fall frost is December 1.
Your McMullen County Garden Planner — Free
A 24-page printable planner built for McMullen County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.