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When to Plant Cowpeas in Jefferson 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.

Jefferson County, Illinois is in USDA Zone 6a. The average last spring frost is April 9 and the first fall frost is October 20, giving you a growing season of approximately 194 days.

At an elevation of 509 feet, Jefferson County receives approximately 34 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Cowpeas during the growing season.

Jefferson County, IL (Zone 6a) Moderate season
194 days
Last Spring Frost April 9
194 growing days
First Fall Frost October 20

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Transplant: Apr 4 🍅 Harvest: Jun 6 – Jul 18
Recommended (50%) ✓ Fits season (89 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 11 – Jul 23
Safe Start (90%) ✓ Fits season (92 days to spare)
Transplant: Apr 19 🍅 Harvest: Jun 21 – Aug 2

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
Drought risk

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

Cowpeas needs ~1,200 GDD — county provides 3,104 GDD Excellent fit

Cowpeas Planting Timeline โ€” Jefferson County, IL

Cowpeas Planting Calendar

Activity When Date Range
Direct Sow April 16 Apr 16 โ€“ May 7
Harvest June 18 Jun 18 โ€“ Jul 30

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 โ€”
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 6a

Growing Season

194 days

Growing Tips for Jefferson 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 Jefferson County, IL?

Jefferson County is in Zone 6a with an average last frost of April 9. Plan your Cowpeas planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, IL?

Jefferson County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 9 and first fall frost is October 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jefferson County gardeners in Zone 6a 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 Jefferson County, IL. Local conditions may vary. Last updated: April 2026.