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When to Plant Sunflower in Thomas County, GA

Thomas County, Georgia Zone 9a May

This month in Thomas County, Georgia

Your garden in Thomas County, Georgia is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost March 4
Avg. first frost November 22
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. Collect sunflower at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Coming up in June — start thinking about
  • First harvests: sunflower

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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.

Thomas County, Georgia is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 22, giving you a growing season of approximately 263 days.

At an elevation of 302 feet, Thomas County receives approximately 58.3 inches of rainfall annually with predominantly clay loam soil. Summer highs average 95°F, so Sunflower may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Sunflower, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Thomas County, GA (Zone 9a) Long season
263 days
Last Spring Frost March 4
263 growing days
First Fall Frost November 22

Thomas County Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (141 days to spare)
Start indoors: Jan 10 Transplant: Feb 28 🍅 Harvest: May 9 – Jun 27
Recommended (50%) ✓ Fits season (137 days to spare)
Start indoors: Jan 21 Transplant: Mar 11 🍅 Harvest: May 20 – Jul 8
Safe Start (90%) ✓ Fits season (140 days to spare)
Start indoors: Feb 11 Transplant: Apr 1 🍅 Harvest: Jun 10 – Jul 29

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 Thomas County

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

Soil pH

Your soil pH (5.5–6.5) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

4
successive plantings in your 263-day season

Sow every 8 weeks. Last sowing by Aug 14 to harvest before frost.

Plant Water Budget

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

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 4.9" 0" ❄️ Dormant
Feb 4.8" 0" ❄️ Dormant
Mar 2.2" 6" 0" ✅ Rainfall sufficient
Apr 2.2" 4.6" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 6" 0" ✅ Rainfall sufficient
Aug 2.2" 5.5" 0" ✅ Rainfall sufficient
Sep 2.2" 4.7" 0" ✅ Rainfall sufficient
Oct 2.2" 3.4" 0" ✅ Rainfall sufficient
Nov 2.2" 4.9" 0" ✅ Rainfall sufficient
Dec 4.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Thomas 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 ~1,806 GDD — county provides 5,588 GDD Excellent fit

Sunflower Planting Timeline — Thomas County, GA

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 21 Jan 21 – Feb 4
Transplant Outdoors March 11 Mar 11 – Mar 25
Direct Sow March 4 Mar 4 – Mar 25
Harvest May 20 May 20 – Jul 8

Plant 1" deep · 18" apart · Rows 30" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April
May Harvest
June Harvest
July Harvest
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

263 days in Thomas County

Growing Tips for Sunflower in Thomas County

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

With Thomas County's clay soil (31% clay), work in 3-4 inches of compost before planting Sunflower. Avoid tilling when soil is wet to prevent compaction.

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

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Thomas County, GA?

Thomas 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 Thomas County, GA?

Thomas County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 22.

🌱

Your Thomas County Garden Planner — Free

A 24-page printable planner built for Thomas 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 Thomas County, GA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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