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When to Plant Soybeans in Caldwell County, NC

Caldwell County, North Carolina Zone 7b May

What to do in May

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

Avg. last frost April 10
Avg. first frost October 26
Soil temp (4") 70°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs

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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.

Caldwell County, North Carolina is in USDA Zone 7b. The average last spring frost is April 10 and the first fall frost is October 26, giving you a growing season of approximately 199 days.

At an elevation of 1,108 feet, Caldwell County receives approximately 46 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°F, 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.

Caldwell County, NC (Zone 7b) Moderate season
199 days
Last Spring Frost April 10
199 growing days
First Fall Frost October 26
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Caldwell County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Transplant: Apr 5 🍅 Harvest: Jun 28 – Aug 23
Recommended (50%) ✓ Fits season (59 days to spare)
Transplant: Apr 10 🍅 Harvest: Jul 3 – Aug 28
Safe Start (90%) ✓ Fits season (56 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 17 – Sep 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 Caldwell County

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

Soil pH

Your soil pH (5.3–6.5) is more acidic than Soybeans prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Soybeans.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Soybeans.

How to Plant Soybeans

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

Succession Planting Soybeans

2
successive plantings in your 199-day season

Sow every 9.1 weeks. Last sowing by Jun 28 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

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 3.6" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 3.8" 0" ❄️ Dormant
Dec 3.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Caldwell County). Supplement amounts are based on average rainfall — 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" — 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.

Soybeans needs ~1,825 GDD — county provides 3,631 GDD Excellent fit

Soybeans Planting Timeline — Caldwell County, NC

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 17 Apr 17 – May 8
Harvest July 10 Jul 10 – Sep 4

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

199 days in Caldwell County

Growing Tips for Soybeans in Caldwell County

Direct sow Soybeans outdoors after April 10 in Caldwell County when soil has warmed and frost danger has passed.

With Caldwell County's clay soil (33% 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 Caldwell County, NC?

Caldwell County is in Zone 7b with an average last frost of April 10. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Caldwell County, NC?

Caldwell County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is April 10 and first fall frost is October 26.

🌱

Your Caldwell County Garden Planner — Free

A 24-page printable planner built for Caldwell County (Zone 7b). 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 Caldwell County, NC. Local conditions may vary. Last updated: May 2026.

Sources & credits

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