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When to Plant Cowpeas in DeWitt County, IL

Cowpeas (black-eyed peas) are a heat-loving legume that fixes nitrogen in the soil. They are drought-tolerant and produce protein-rich pods in hot conditions.

DeWitt County, Illinois is in USDA Zone 5b. The average last spring frost is April 15 and the first fall frost is October 17, giving you a growing season of approximately 185 days.

At an elevation of 801 feet, DeWitt County receives approximately 31.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Cowpeas to ensure they mature before fall.

DeWitt County, IL (Zone 5b) Moderate season
185 days
Last Spring Frost April 15
185 growing days
First Fall Frost October 17

DeWitt County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Transplant: Apr 10 🍅 Harvest: Jun 12 – Jul 24
Recommended (50%) ✓ Fits season (80 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 29
Safe Start (90%) ✓ Fits season (82 days to spare)
Transplant: Apr 28 🍅 Harvest: Jun 30 – Aug 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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Cowpeas needs ~975 GDD — county provides 2,405 GDD Excellent fit

Cowpeas Planting Timeline โ€” DeWitt County, IL

Cowpeas Planting Calendar

Activity When Date Range
Direct Sow April 22 Apr 22 โ€“ May 13
Harvest June 24 Jun 24 โ€“ Aug 5

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 Direct Sow
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

60โ€“90 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 5b

Growing Season

185 days

Growing Tips for DeWitt County

Direct sow after soil is thoroughly warm. Do not over-fertilize with nitrogen as cowpeas fix their own. Harvest pods when they begin to dry on the vine for dry beans.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Onion

Level Up Your Garden

Frequently Asked Questions

When should I plant Cowpeas in DeWitt County, IL?

DeWitt County is in Zone 5b with an average last frost of April 15. Plan your Cowpeas planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is DeWitt County, IL?

DeWitt County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 15 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help DeWitt County gardeners in Zone 5b 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 DeWitt County, IL. Local conditions may vary. Last updated: April 2026.