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When to Plant Soybeans in Cullman County, AL

Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.

Cullman County, Alabama is in USDA Zone 7a. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.

At an elevation of 347 feet, Cullman County receives approximately 53.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91ยฐF, providing good warmth for Soybeans during the growing season. Clay soil retains moisture well for Soybeans, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.

Cullman County, AL (Zone 7a) Long season
219 days
Last Spring Frost March 28
219 growing days
First Fall Frost November 2

Cullman County Soil Profile

Soil Type

Clay Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (80 days to spare)
Transplant: Mar 21 🍅 Harvest: Jun 13 – Aug 8
Recommended (50%) ✓ Fits season (79 days to spare)
Transplant: Mar 28 🍅 Harvest: Jun 20 – Aug 15
Safe Start (90%) ✓ Fits season (77 days to spare)
Transplant: Apr 19 🍅 Harvest: Jul 12 – Sep 6

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 Cullman County

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

Soil pH

Your soil pH (5.4โ€“6.8) overlaps with Soybeans's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The clay loam soil in Cullman County is excellent for Soybeans โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Soybeans.

Organic Matter

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

How to Plant Soybeans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Soybeans

3
successive plantings in your 219-day season

Sow every 9.1 weeks. Last sowing by Jul 05 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Soybeans

Soybeans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Soybeans Needs Rainfall You Supplement Action
Jan โ€” 4" 0" โ„๏ธ Dormant
Feb โ€” 4" 0" โ„๏ธ Dormant
Mar 4.3" 5.3" 0" โœ… Rainfall sufficient
Apr 4.3" 4.4" 0" โœ… Rainfall sufficient
May 4.3" 4.3" 0" โœ… Rainfall sufficient
Jun 4.3" 4.8" 0" โœ… Rainfall sufficient
Jul 4.3" 5.2" 0" โœ… Rainfall sufficient
Aug 4.3" 5.4" 0" โœ… Rainfall sufficient
Sep 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Oct 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Nov 4.3" 4.4" 0" โœ… Rainfall sufficient
Dec โ€” 3.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Cullman County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Soybeans 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" โ€” every day above 50ยฐF 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.

Soybeans needs ~1,825 GDD — county provides 3,996 GDD Excellent fit

Soybeans Planting Timeline โ€” Cullman County, AL

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 4 Apr 4 โ€“ Apr 25
Harvest June 27 Jun 27 โ€“ Aug 22

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

219 days in Cullman County

Growing Tips for Soybeans in Cullman County

Direct sow Soybeans outdoors after March 28 in Cullman County when soil has warmed and frost danger has passed.

With Cullman County's clay soil (30% clay), work in 3-4 inches of compost before planting Soybeans. Avoid tilling when soil is wet to prevent compaction.

Common pests for Soybeans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after soil warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Soybeans in Cullman County, AL?

Cullman County is in Zone 7a with an average last frost of March 28. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cullman County, AL?

Cullman County, Alabama is in USDA Hardiness Zone 7a. The average last spring frost is March 28 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Cullman County, AL. Local conditions may vary. Last updated: April 2026.