When to Plant Cowpeas in Randolph 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.
Randolph County, Illinois is in USDA Zone 6a. The average last spring frost is April 11 and the first fall frost is October 20, giving you a growing season of approximately 192 days.
At an elevation of 501 feet, Randolph County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Cowpeas during the growing season.
Randolph County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.8
Drainage
Well Drained
Plant Planting Risk Windows
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 Randolph County
How your county's soil matches Cowpeas's growing requirements.
Soil pH
Your soil pH (5.7–6.8) is within Cowpeas's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Randolph County is excellent for Cowpeas — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — Cowpeas will thrive.
How to Plant Cowpeas
Succession Planting Cowpeas
Sow every 6.9 weeks. Last sowing by Jul 22 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Cowpeas
Cowpeas needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Cowpeas Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Randolph County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cowpeas 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.
Cowpeas Planting Timeline — Randolph County, IL
Cowpeas Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 18 | Apr 18 – May 9 |
| Harvest | June 20 | Jun 20 – Aug 1 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 6a
📆 Growing Season
192 days in Randolph County
Growing Tips for Cowpeas in Randolph County
Direct sow Cowpeas outdoors after April 11 in Randolph County when soil has warmed and frost danger has passed.
Common pests for Cowpeas 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 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
Check more plant combinations with our Companion Planting Checker →
Cowpeas in Other Locations
Frequently Asked Questions
When should I plant Cowpeas in Randolph County, IL?
Randolph County is in Zone 6a with an average last frost of April 11. Plan your Cowpeas planting based on this frost date — see the calendar above for exact timing.
What planting zone is Randolph County, IL?
Randolph County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 11 and first fall frost is October 20.
Plan Your Garden with Confidence
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