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When to plant Sunflower in Effingham County, GA

Aim to plant Sunflower in Effingham County on or after February 20; the window stays open through March 13. Effingham County's 249-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Sunflower in Effingham County, GA

Effingham County, Georgia Zone 9a June

Your June game plan for Effingham County, Georgia

Your Effingham County, Georgia garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost March 13
Avg. first frost November 17
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Harvest sunflower as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

To set up a strong July, finish these tasks
  • 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.

Effingham County, Georgia is in USDA Zone 9a. The average last spring frost is March 13 and the first fall frost is November 17, giving you a growing season of approximately 249 days.

At an elevation of 344 feet, Effingham County receives approximately 60.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sunflower will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Effingham County, GA (Zone 9a) Long season
249 days
Last Spring Frost March 13
249 growing days
First Fall Frost November 17

Effingham County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.9-6.3

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Feb 12 Transplant: Feb 12 🌸 Bloom: May 7 – Oct 8
Recommended (50%) ✓ Fits season (32 days to spare)
Start indoors: Feb 20 Transplant: Feb 20 🌸 Bloom: May 15 – Oct 16
Safe Start (90%) ✓ Fits season (28 days to spare)
Start indoors: Mar 18 Transplant: Mar 18 🌸 Bloom: Jun 10 – Nov 11

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 Effingham County

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

Soil pH

Your soil pH (4.9–6.3) is more acidic than Sunflower prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Effingham County warms quickly in spring but drains fast. Sunflower will need more frequent watering and regular compost additions to retain nutrients.

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 249-day season

Sow every 8 weeks. Last sowing by Aug 09 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

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 4.8" 0" ❄️ Dormant
Feb 5.4" 0" ❄️ Dormant
Mar 2.2" 5.6" 0" ✅ Rainfall sufficient
Apr 2.2" 4" 0" ✅ Rainfall sufficient
May 2.2" 5" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 6.7" 0" ✅ Rainfall sufficient
Aug 2.2" 5.7" 0" ✅ Rainfall sufficient
Sep 2.2" 4.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 5.1" 0" ✅ Rainfall sufficient
Dec 4.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Effingham 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 ~1,934 GDD — county provides 5,664 GDD Excellent fit

Sunflower Planting Timeline — Effingham County, GA

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors February 20 Feb 20 – Mar 6
Direct Sow February 20 Feb 20 – Mar 13
Bloom May 15 May 15 – Oct 16

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March Start Indoors Transplant Outdoors 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: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

249 days in Effingham County

Growing Tips for Sunflower in Effingham County

Direct sow Sunflower outdoors after March 13 in Effingham County when soil has warmed and frost danger has passed.

Sandy soil in Effingham County dries quickly — mulch Sunflower with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 97°F in Effingham 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

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Effingham County, GA?

Effingham County is in Zone 9a with an average last frost of March 13. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Effingham County, GA?

Effingham County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is March 13 and first fall frost is November 17.

When should I plant Sunflower in Effingham County, GA?

In Effingham County, GA, plant Sunflower after the last frost (around March 13) and before the first frost (around November 17). Best results when soil holds above 50°F.

What growing zone is Effingham County, GA for Sunflower?

Effingham County sits in USDA Zone 9a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Effingham County's climate?

Yes — Sunflower grows well in Effingham County's temperate climate. Effingham County averages a 249-day frost-free season, with last frost around March 13 and first frost around November 17.

🌱

Your Effingham County Garden Planner — Free

A 22-page printable planner built for Effingham 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 Effingham County, GA. 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.