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When to Plant Cowpeas in Harmon County, OK

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.

Harmon County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 5, giving you a growing season of approximately 219 days.

At an elevation of 993 feet, Harmon County receives approximately 34.4 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Cowpeas during the growing season.

Harmon County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 31
219 growing days
First Fall Frost November 5

Harmon County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Cowpeas Planting Timeline — Harmon County, OK

Cowpeas Planting Calendar

Activity When Date Range
Direct Sow April 7 Apr 7 – Apr 28
Harvest June 9 Jun 9 – Jul 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7b

📆 Growing Season

219 days in Harmon County

Growing Tips for Harmon 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cowpeas in Harmon County, OK?

Harmon County is in Zone 7b with an average last frost of March 31. Plan your Cowpeas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harmon County, OK?

Harmon County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 5.

🌱

Your Harmon County Garden Planner — Free

A 22-page printable planner built for Harmon 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.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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