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When to Plant Sunflower in Wilson County, TX

Wilson County, Texas Zone 9a June

June in Wilson County, Texas — your action list

A quick June briefing for Wilson County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 4
Avg. first frost November 25
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Collect sunflower at their peak

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

A few tasks this June that'll pay off in July
  • First harvests: sunflower

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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.

Wilson County, Texas is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 25, giving you a growing season of approximately 266 days.

At an elevation of 2,660 feet, Wilson County receives approximately 62.3 inches of rainfall annually with predominantly loam soil. Summer highs average 93°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.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Wilson County, TX (Zone 9a) Long season
266 days
Last Spring Frost March 4
266 growing days
First Fall Frost November 25

Wilson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Start indoors: Jan 30 Transplant: Jan 30 🌸 Bloom: Apr 24 – Sep 25
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Feb 11 Transplant: Feb 11 🌸 Bloom: May 6 – Oct 7
Safe Start (90%) ✓ Fits season (40 days to spare)
Start indoors: Mar 9 Transplant: Mar 9 🌸 Bloom: Jun 1 – Nov 2

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 Wilson County

How your county's soil matches Sunflower's growing requirements.

Soil pH

Your soil pH (6.5–7.4) is within Sunflower's preferred range (6.0–7.5).

Soil Texture

The loam soil in Wilson County is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sunflower.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Sunflower

4
successive plantings in your 266-day season

Sow every 8 weeks. Last sowing by Aug 17 to harvest before frost.

Sunflower Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.2" 4.2" 0" ✅ Rainfall sufficient
Apr 2.2" 5.6" 0" ✅ Rainfall sufficient
May 2.2" 9.2" 0" ✅ Rainfall sufficient
Jun 2.2" 10.7" 0" ✅ Rainfall sufficient
Jul 2.2" 8.7" 0" ✅ Rainfall sufficient
Aug 2.2" 7.7" 0" ✅ Rainfall sufficient
Sep 2.2" 5.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 2.1" 0.1" 💧 Light watering
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Wilson 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 needs ~1,679 GDD — county provides 5,253 GDD Excellent fit

Sunflower Planting Timeline — Wilson County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors February 11 Feb 11 – Feb 25
Direct Sow February 11 Feb 11 – Mar 4
Bloom May 6 May 6 – Oct 7

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March 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

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

266 days in Wilson County

Growing Tips for Sunflower in Wilson County

Direct sow Sunflower outdoors after March 04 in Wilson County when soil has warmed and frost danger has passed.

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

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Wilson County, TX?

Wilson County is in Zone 9a with an average last frost of March 4. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wilson County, TX?

Wilson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 25.

🌱

Your Wilson County Garden Planner — Free

A 22-page printable planner built for Wilson 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Wilson County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.