In the Spring, plant cowpeas after all danger of frost has passed and temperatures are consistently 65F. The colder the soil, the longer it will take for the seeds to germinate. For Fall planting, sow early enough so that harvesting can be completed before damaging frost occurs, about 14 weeks before first average Spring frost.
Plant cowpea seeds 1-2 inches deep and 2-4 inches apart in the rows spaced 2-3 feet apart. Planting in fertile, moist, well-draining soil is best for seeds to germinate and emerge quickly.
Watering: Cowpeas can withstand heat and dry conditions well compared to other vegetables, but yields can increase with good watering and rainfall. Water plants about 1 inch every 7-10 days when established.
Weeding: Weeds consume about as much water as the cowpea plant itself so try to pull weeds when possible, but be careful not to pull the delicate roots of the plant.
Fertilizing: Soil pH between 6.0-6.5 is best but cowpeas are tolerant of many soil conditions. Fertilizer is optional but 4-12-12 or 5-10-10 are good options if choosing to fertilizer. Apply by broadcasting or creating a 4 inch deep band along the row, 3 inches away from the seed. Water plants after fertilizing.
Insecticides: Insecticides may be used to protect plants. Bt-based insecticides and sulfur are organic options. Sulfur also has fungicidal properties and helps in controlling many diseases. Before using a pesticide, read the label and always follow cautions, warnings and directions.
Diseases: Diseases may be a possibility during cool, wet weather. If spots appear on leaves or bean pods, treat the plant with an approved fungicide. Neem oil, sulfur, and other fungicides may be used.
For fresh cowpeas, pick individual pods when the pods are at least 6 inches in length, their seeds fill the pods well, and they are easily snapped like green beans. For dry beans, pull up the whole plant when 90% of the pods have dried off and seeds are hardened. Spread the plant in a safe area to complete the drying of the pods. Leaving the pods to completely dry on the plant may risk field weathering and losing or breaking the seeds. Break completely dried pods down the middle and push out the seeds. Store the seeds in an airtight container until ready to use.