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When to plant Sunflower in Calhoun County, AL

In Calhoun County, plant Sunflower in spring between March 24 and April 14, once soil temps hold above 50°F. Calhoun County's last frost averages March 31, so most warm-season crops establish quickly once soil holds above 60°F. For a fall crop, sow between and — roughly 70–100 days before the first frost on October 31.

When to Plant Sunflower in Calhoun County, AL

Calhoun County, Alabama Zone 8a June

June to-do list for Calhoun County, Alabama

Your garden in Calhoun County, Alabama is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost March 31
Avg. first frost October 31
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Basket week: sunflower

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

Looking ahead to 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.

Calhoun County, Alabama is in USDA Zone 8a. The average last spring frost is March 31 and the first fall frost is October 31, giving you a growing season of approximately 214 days.

At an elevation of 440 feet, Calhoun County receives approximately 52.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 94°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
Calhoun County, AL (Zone 8a) Long season
214 days
Last Spring Frost March 31
214 growing days
First Fall Frost October 31

Calhoun County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.4

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Mar 4 Transplant: Mar 18 🌸 Bloom: Jun 10 – Oct 14
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Mar 10 Transplant: Mar 24 🌸 Bloom: Jun 16 – Oct 20
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: Mar 28 Transplant: Apr 11 🌸 Bloom: Jul 4 – Nov 7

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 Calhoun County

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

Soil pH

Your soil pH (5.3–6.4) is more acidic than Sunflower prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Sunflower.

How to Plant Sunflower

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

Succession Planting Sunflower

3
successive plantings in your 214-day season

Sow every 8 weeks. Last sowing by Jul 23 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" 0" ❄️ Dormant
Feb 3.7" 0" ❄️ Dormant
Mar 2.2" 5.7" 0" ✅ Rainfall sufficient
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 5" 0" ✅ Rainfall sufficient
Jul 2.2" 5.4" 0" ✅ Rainfall sufficient
Aug 2.2" 5.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 4.2" 0" ❄️ Dormant
Dec 4.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Oct in Calhoun 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 ~1,742 GDD — county provides 4,387 GDD Excellent fit

Sunflower Planting Timeline — Calhoun County, AL

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors March 24 Mar 24 – Apr 7
Direct Sow March 24 Mar 24 – Apr 14
Bloom June 16 Jun 16 – Oct 20

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May
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 8a

📆 Growing Season

214 days in Calhoun County

Growing Tips for Sunflower in Calhoun County

Direct sow Sunflower outdoors after March 31 in Calhoun County when soil has warmed and frost danger has passed.

With Calhoun 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 Calhoun County, AL?

Calhoun County is in Zone 8a with an average last frost of March 31. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Calhoun County, AL?

Calhoun County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is March 31 and first fall frost is October 31.

When should I plant Sunflower in Calhoun County, AL?

In Calhoun County, AL, plant Sunflower after the last frost (around March 31) and before the first frost (around October 31). Best results when soil holds above 50°F.

What growing zone is Calhoun County, AL for Sunflower?

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

Can Sunflower grow in Calhoun County's climate?

Yes — Sunflower grows well in Calhoun County's temperate climate. Calhoun County averages a 214-day frost-free season, with last frost around March 31 and first frost around October 31.

🌱

Your Calhoun County Garden Planner — Free

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

Sources & credits

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