The purple hull pea, a popular variety of cowpea, is a warm-weather crop deeply valued as a summer staple across Arkansas. This heat-tolerant legume thrives in the long, hot growing season of the South. Achieving a bountiful harvest depends on precise timing, as planting too early can result in crop failure. The correct planting window is dictated by the soil’s temperature and the complete absence of any frost threat.
Optimal Timing Based on Soil Temperature
Successful planting of purple hull peas relies on the soil being sufficiently warm, as these seeds will not germinate in cool, wet conditions and are prone to rotting. The minimum temperature for planting is 60 degrees Fahrenheit, but optimal germination occurs when the soil temperature consistently registers between 65 and 70 degrees Fahrenheit. Gardeners should use a soil thermometer, checking the temperature at a depth of about two inches each morning for several consecutive days to verify conditions are right.
In Arkansas, the period when the soil reaches this threshold typically follows the average last spring frost, which varies significantly by region. Southern Arkansas often sees its last frost in March, allowing for planting in late April or early May. Northern Arkansas, especially in higher elevations, may not see the last frost until late April or early May, pushing the safe planting time closer to mid-May or early June. Planting after the danger of frost has passed ensures rapid and uniform germination.
Preparing the Soil and Planting Method
Purple hull peas perform well in well-drained soil types, preferring a slightly acidic to neutral pH range of 5.8 to 7.0. Preparing the soil involves ensuring good drainage and incorporating organic matter, which supports healthy root development. These plants are legumes, meaning they work with symbiotic bacteria to fix atmospheric nitrogen into the soil, significantly reducing the need for nitrogen fertilizer.
Applying too much nitrogen will result in excessive vine growth at the expense of pod production. It is recommended to provide only a light application of phosphorus and potassium before planting, especially if a soil test indicates a deficiency. Seeds should be sown directly into the garden bed at a depth of one to two inches. Spacing the seeds three to six inches apart within the row allows for adequate air circulation and plant development, setting the stage for high yields.
Succession Planting for Extended Yield
To maximize the harvest period throughout the summer months, gardeners can employ succession planting by staggering their seeding schedule. This method involves planting a new batch of seeds every two to three weeks, ensuring a continuous supply of fresh peas rather than one large, overwhelming harvest. Purple hull peas typically reach maturity for fresh eating in about 60 to 75 days, depending on the specific variety and environmental conditions.
The final planting must be timed to allow the crop to fully mature before the first expected fall frost. In Southern Arkansas, the cutoff for the last planting is generally the first week of August. Gardeners in Northern Arkansas may need to stop planting by mid-July. Calculating back 65 to 75 days from the average first frost date in your specific area is the best way to determine the latest date for successful production.