Differences of as short as 12 min can affect flowering and seed yield. They tolerate heat and relatively dry conditions and can be grown with less rainfall and under more adverse conditions than Phaseolus vulgaris or P. lunatus. Night temperatures strongly affect many phases of the life cycle and differences in day temperature during reproductive growth markedly affect crop duration and yield. Marked cv differences in environmental responses have been identified. Cultivation Seeds remain viable for several years.
Germination is epigeal.
Should be planted after danger from frost is past. If seeded for hay or seed, crop should be sown early, but for green manure and pasture purposes, may be seeded late with good results. Cowpeas may be planted in rows, broadcast, or mixed with such other plants as cassava, corn, sorghum, sudangrass, johnsongrass, millets, peanuts, or soybeans. When grown for seed, it is painted in rows, for forage or green manture, broadcast. For hog feed or silage, cowpeas are planted with corn, either at the sime time as or at the last cultivation of corn.