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When to plant Sunflower in Henry County, AL

Spring Sunflower in Henry County goes in February 23–March 16, once nighttime temps stop dipping near freezing.

When to Plant Sunflower in Henry County, AL

Henry County, Alabama Zone 8b July

July in Henry County, Alabama — your action list

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 9
Avg. first frost November 17
Soil temp (4") 90°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Start harvesting sunflower

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Looking ahead to August
  • 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.

Henry County, Alabama is in USDA Zone 8b. The average last spring frost is March 9 and the first fall frost is November 17, giving you a growing season of approximately 253 days.

At an elevation of 195 feet, Henry County receives approximately 61.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°F, providing good warmth for Sunflower during the growing season. 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.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Henry County, AL (Zone 8b) Long season
253 days
Last Spring Frost March 9
253 growing days
First Fall Frost November 17

Henry County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.2

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Feb 10 Transplant: Feb 17 🌸 Bloom: May 12 – Sep 29
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Feb 16 Transplant: Feb 23 🌸 Bloom: May 18 – Oct 5
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Mar 9 Transplant: Mar 16 🌸 Bloom: Jun 8 – Oct 26

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 Henry County

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

Soil pH

Your soil pH (5.7–6.2) is more acidic than Sunflower prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

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 253-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 5.5" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 2.2" 6.2" 0" ✅ Rainfall sufficient
Apr 2.2" 4.1" 0" ✅ Rainfall sufficient
May 2.2" 5.4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 6.1" 0" ✅ Rainfall sufficient
Aug 2.2" 5.9" 0" ✅ Rainfall sufficient
Sep 2.2" 5" 0" ✅ Rainfall sufficient
Oct 2.2" 4.2" 0" ✅ Rainfall sufficient
Nov 2.2" 4.9" 0" ✅ Rainfall sufficient
Dec 4.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Henry 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 ~1,551 GDD — county provides 4,617 GDD Excellent fit

Sunflower Planting Timeline — Henry County, AL

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 – Mar 2
Transplant Outdoors February 23 Feb 23 – Mar 9
Direct Sow February 23 Feb 23 – Mar 16
Bloom May 18 May 18 – Oct 5

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 8b

📆 Growing Season

253 days in Henry County

Growing Tips for Sunflower in Henry County

Direct sow Sunflower outdoors after March 09 in Henry County when soil has warmed and frost danger has passed.

With Henry County's clay soil (27% 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 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 Henry County, AL?

Henry County is in Zone 8b with an average last frost of March 9. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Henry County, AL?

Henry County, Alabama is in USDA Hardiness Zone 8b. The average last spring frost is March 9 and first fall frost is November 17.

When should I plant Sunflower in Henry County, AL?

In Henry County, AL, plant Sunflower after the last frost (around March 9) and before the first frost (around November 17). Best results when soil holds above 50°F.

What growing zone is Henry County, AL for Sunflower?

Henry County sits in USDA Zone 8b. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Henry County's climate?

Yes — Sunflower grows well in Henry County's temperate climate. Henry County averages a 253-day frost-free season, with last frost around March 9 and first frost around November 17.

🌱

Your Henry County Garden Planner — Free

A 22-page printable planner built for Henry County (Zone 8b). 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 Henry County, AL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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