When to Plant Cowpeas in Benton County, OR
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.
Benton County, Oregon is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 30, giving you a growing season of approximately 199 days.
At an elevation of 97 feet, Benton County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Cowpeas during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cowpeas root diseases.
Benton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.2
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.
Plant Water Budget
Cowpeas Planting Timeline — Benton County, OR
Cowpeas Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 21 | Apr 21 – May 12 |
| Harvest | June 23 | Jun 23 – Aug 4 |
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
Low — drought tolerant
Days to Maturity
60–90 days
Soil pH
5.5 – 7
USDA Zone
Zone 8a
Growing Season
199 days
Growing Tips for Benton 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
Level Up Your Garden
Cowpeas in Other Locations
Frequently Asked Questions
When should I plant Cowpeas in Benton County, OR?
Benton County is in Zone 8a with an average last frost of April 14. Plan your Cowpeas planting based on this frost date — see the calendar above for exact timing.
What planting zone is Benton County, OR?
Benton County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 30.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Benton County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.
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