Cowpeas, unlike field peas, are a warm season annual. They cannot be successfully planted until soil temperatures reach 65°F. This limits their usefulness in the North. They are usually only used as a smother or soil building crop.
In our southern regions, cowpeas are used only as a double crop with short season corn or sorghum. Some would even plant sorghum with cowpeas, but the caution is to not depend on the cowpeas for the sorghum's nitrogen. Their roles are to suppress weeds, build soil, prevent erosion, produce 90 to 120 lbs. of N and can even be used as forage. The N production though modest, can be accompanied with up to 8000 lbs./A biomass. Often, they are used as a summer soil building, sacrifice crop/ green manure.
- Double crop or companion crop in the South
- Smother crop or soil builder for the North
- Provides soil building, quick cover & weed suppression
Zones: 1, 2, 3, 4, 5, 6
Cowpeas can tolerate a wide range of soil types, low fertility, high heat and both moist or dry (once germinated) soils. Do not allow cowpeas to go to seed. Mowing or rolling stops plant development, but does not kill. Quickly incorporate with light tillage to get fastest release of the plant's nutrients.
Cowpeas used for cover crops will unlikely have any problems with pests as might those grown for their grain.
Drill at 25 to 50 lb./A 1⁄2" to 1" deep, or broadcast up to 120 lb./A in a weed-free field. Inoculate the seeds for best performance. Cowpeas can tolerate lower pH although will do best with adequate lime.