Cowpea (black eyed pea) is a warm season annual legume with a wide range of growth habits from prostrate, to short and bushy to tall and vine-like with a strong taproot. It is commonly cultivated for human consumption and is also used as forage, hay and silage and in cover crop applications in the southern United States and throughout the tropics and subtropics.
Depending on variety, it may grow 2-3 feet tall. Leaves are trifoliate, egg-shaped and hairless, approximately four inches long and three inches wide. Cowpea performs best on well-drained sandy loam or sandy soil where pH ranges from 5.5-6.5. Daytime temperatures of 80°F and consistent soil temperatures of at least 65°F are optimum for germination and growth of cowpea.
In areas with warm enough conditions, a cowpea cover crop can produce 2,500-4,500 lbs/ac dry matter and provide 100-150 lbs/ ac of nitrogen to a subsequent crop. It may have limited application in our region as a mid-summer cover or green manure crop because of the warm soil temperature requirements. For forage or cover crop applications cowpea can be seeded in rows or broadcast.
Recommended seeding rates range from 18-22 lbs/ac for viney, indeterminate types and 40-50 lbs/ac for large seeded, determinate types. Recommended seeding depth is 0.5- 1.5 inches.