Blog

When to Plant Cowpeas in Los Alamos County, NM

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.

Los Alamos County, New Mexico is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.

At an elevation of 5,220 feet, Los Alamos County receives approximately 12.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87ยฐF, providing good warmth for Cowpeas during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Cowpeas will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Cowpeas successfully. Mulch heavily to conserve soil moisture.

Los Alamos County, NM (Zone 6a) Moderate season
150 days
Last Spring Frost May 10
150 growing days
First Fall Frost October 7

Los Alamos County Soil Profile

Soil Type

Sandy Loam

Soil pH

7-8.6

Drainage

Well Drained

Monthly Watering Guide for Cowpeas

Cowpeas needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cowpeas Needs Rainfall You Supplement Action
Jan โ€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 0.6" 0" โ„๏ธ Dormant
Mar โ€” 0.8" 0" โ„๏ธ Dormant
Apr โ€” 0.4" 0" โ„๏ธ Dormant
May 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Jun 4.3" 0.4" 3.9" ๐Ÿšฟ Regular watering
Jul 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Aug 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Sep 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Oct 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Nov โ€” 0.7" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Los Alamos County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Cowpeas Planting Timeline โ€” Los Alamos County, NM

Cowpeas Planting Calendar

Activity When Date Range
Direct Sow May 17 May 17 โ€“ Jun 7
Harvest July 19 Jul 19 โ€“ Aug 30

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Low โ€” drought tolerant

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

150 days in Los Alamos County

Growing Tips for Los Alamos 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 Los Alamos County, NM?

Los Alamos County is in Zone 6a with an average last frost of May 10. Plan your Cowpeas planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Los Alamos County, NM?

Los Alamos County, New Mexico is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Los Alamos County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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