How to Grow Cowpeas
Although cowpea is a well known garden plant in the South, this crop deserves more attention across the country. Its long, slender pods are filled with a prolific number of seeds.
Time of Planting
Most gardeners plant cowpea seeds directly outdoors, once the danger of frost has passed. Water seeds well to speed up germination.
Plant the cowpea seeds 2-3 inches apart, ½ inch deep directly into warm soil.
Time to Germination
Cowpeas are quick to germinate.
Different varieties of cowpeas have different growing habits. Some cowpeas climb like pole beans while others form compact plants like bush beans.
Common Pests and Diseases
Cowpeas can be affected by a number of diseases and are susceptible to viral infections. Some of these bacterial and fungal diseases can remain in the soil for several years, so grow cowpeas in different areas of your garden each year. To prevent the spread of fungal and bacterial diseases among plants, avoid working in your bean patch when the foliage is wet. The best way to get rid of beetles and bugs that might eat the leaves of your plants is to pick them off and toss them into a jar of soapy water. Promptly cut down and compost plants that are past their prime to interrupt the life cycles of pests and diseases.
When and How to Harvest
For culinary use, cowpeas can be harvested early, like green beans, or later in the season when the pods are dry and brittle, and the seeds inside are hard.
Young cowpea pods are best eaten fresh, canned, or frozen. Dry cowpeas must be soaked and boiled before eating.
Cowpeas can be stored dry for years.
How to Save Cowpea Seeds
Saving seeds from these crops is easy whether plants are grown for their immature beans (some pods are simply left on the vine to reach seed maturity) or if they are grown for their dry beans, in which case harvesting for food and harvesting for seed are one and the same. Given the relatively short isolation distance necessary to maintain a variety, a gardener can even grow and save seeds from more than one cultivar in the same season.
Recommended Isolation Distance
Separate varieties by 10-20 feet.
Recommended Population Sizes
To ensure viable seeds, save seeds from at least 1 plant. When maintaining a variety over many generations, save seeds from 10-25 plants. If you’re saving seeds for genetic preservation of a rare variety, save seeds from 50 plants.
Assessing Seed Maturity
Seeds are mature when pods turn tan.
Cultivars of cowpeas and yardlong beans vary in their tendency to shatter (when the fruits split to disperse seeds). The pods are mature enough to harvest once they have begun to turn yellow, but if they are monitored carefully to avoid shattering, they can be left on the plants until they are tan and dry. Individual pods can be picked as they mature, or whole plants can be uprooted or cut at the base and spread out on row cover in a sheltered location to finish maturing and drying. Plants should be left to dry until the pods are brittle and the seeds become too hard to dent with a fingernail.
Cleaning and Processing
When the cowpea pods are completely dry, break them open to release the seeds. Separate the seeds from the chaff. If you are saving a large number of cowpea seeds, you can thresh and winnow the pods to separate the seeds and chaff.
Storage and Viability
Store cowpeas in a cool, dark, and dry place in an airtight container to keep out moisture and humidity. Under these conditions, cowpea seeds will last 3-4 years.