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When to Plant Sunflower in Calhoun County, AL

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.

Calhoun County, Alabama is in USDA Zone 7b. 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 94ยฐF, 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.

Calhoun County, AL (Zone 7b) 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

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jun 17 – Aug 5
Recommended (50%) ✓ Fits season (81 days to spare)
Start indoors: Feb 10 Transplant: Apr 14 🍅 Harvest: Jun 23 – Aug 11
Safe Start (90%) ✓ Fits season (77 days to spare)
Start indoors: Feb 28 Transplant: May 2 🍅 Harvest: Jul 11 – Aug 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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sunflower needs ~1,742 GDD — county provides 4,387 GDD Excellent fit

Sunflower Planting Timeline โ€” Calhoun County, AL

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 โ€“ Feb 24
Transplant Outdoors April 14 Apr 14 โ€“ Apr 28
Direct Sow April 7 Apr 7 โ€“ Apr 28
Harvest June 23 Jun 23 โ€“ Aug 11

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March โ€”
April Transplant Outdoors Direct Sow
May โ€”
June Harvest
July Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 7b

Growing Season

214 days

Growing Tips for Calhoun County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunflower in Calhoun County, AL?

Calhoun County is in Zone 7b with an average last frost of March 31. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Calhoun County, AL?

Calhoun County, Alabama is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is October 31.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Calhoun County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

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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: April 2026.