Cowpea is considered more tolerant to drought than even soybeans or mung beans, due to its tendency to form a deep tap root. By nature the plant is a vine, hence the best breeding opportunities for modem agriculture systems is with the more determinate and bush types, although for forage or cover crop applications the vine characteristic is preferred. There is a fairly active breeding program throughout the primary production areas, which include the Southeastern U.S., Arkansas, California, and Texas. Yield information is available on the varieties released from these programs. All cultivated cowpea varieties are considered warm season and adapted to heat and drought conditions.
Some varieties are erect and bushy, while others are viney in growth habit.
The seed pods are borne above the leaf axil, thus the pods are very visible. The seed pod is typically 3 to 6 inches long and has 6 to 13 seeds per pod. The seed weight per bushel is 60 pounds with about 3000 to 4000 seeds per pound. Leaves will dry down but may not drop off completely. Due to its drought tolerance, cowpea has a competitive niche in soils that are sandy.