When to Plant Sunflower in Wharton 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.
Wharton County, Texas is in USDA Zone 9a. The average last spring frost is February 17 and the first fall frost is December 6, giving you a growing season of approximately 292 days.
At an elevation of 207 feet, Wharton County receives approximately 64.8 inches of rainfall annually with predominantly loam soil. Summer highs average 98°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.
Wharton County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.7
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 Wharton County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (6.6–7.7) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Wharton County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Sunflower.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Aug 28 to harvest before frost.
Plant Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 10.4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 8.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 7.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Dec | 2.2" | 1.9" | 0.3" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Wharton 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 — Wharton County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 6 | Jan 6 – Jan 20 |
| Transplant Outdoors | February 24 | Feb 24 – Mar 10 |
| Direct Sow | February 17 | Feb 17 – Mar 10 |
| Harvest | May 5 | May 5 – Jun 23 |
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: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
292 days in Wharton County
Growing Tips for Sunflower in Wharton County
Direct sow Sunflower outdoors after February 17 in Wharton County when soil has warmed and frost danger has passed.
With summer highs reaching 98°F in Wharton 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 Wharton County, TX?
Wharton County is in Zone 9a with an average last frost of February 17. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Wharton County, TX?
Wharton County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 17 and first fall frost is December 6.
Plan Your Garden with Confidence
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