When to Plant Sunflower in Wharton County, TX
This month in Wharton County, Texas
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Bring in the sunflower
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
July prep starts now
- First harvests: sunflower
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.
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
Sunflower 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.
Sunflower 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 27 | Jan 27 – Feb 10 |
| Transplant Outdoors | January 27 | Jan 27 – Feb 10 |
| Direct Sow | January 27 | Jan 27 – Feb 17 |
| Bloom | April 21 | Apr 21 – Sep 22 |
Plant 1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Transplant Outdoors Direct Sow |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | — |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| 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 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 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.
Your Wharton County Garden Planner — Free
A 22-page printable planner built for Wharton County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.