Cowpeas, scientifically known as Vigna unguiculata, are a highly attractive and nutritious warm-season annual. This legume is a top choice for wildlife managers due to its high palatability and exceptional crude protein content, which is vital during the summer months. Successful cowpea planting depends less on a calendar date and more on ideal soil conditions to ensure a robust forage crop. Understanding the plant’s needs and the proper planting window is key to maximizing its value as a food source.
Why Cowpeas Are Ideal Deer Forage
Cowpeas are prized for their exceptional nutritional profile, often containing between 25% and 30% crude protein when grown in fertile soil conditions. This high level of protein is beneficial for bucks during antler growth and for does that are lactating and raising fawns. The foliage is highly digestible, providing the necessary building blocks for herd health and development throughout the summer and early fall.
The plant is a warm-season annual that produces a significant amount of biomass quickly. Cowpeas are also drought-tolerant, making them a reliable option in regions that experience hot, dry weather. Common varieties like Iron & Clay or Whippoorwill produce viney, leafy growth that deer readily consume until the first hard frost.
Determining the Optimal Planting Window
The timing for planting cowpeas is primarily dictated by soil temperature, which must consistently be above 60°F for optimal germination and emergence. Planting too early risks poor germination and seedling rot in cold, wet soil, while planting too late can limit the overall production window. The most reliable method is to check the soil temperature at a two-inch depth around 9:00 a.m. for several consecutive mornings.
Generally, the planting window begins in late spring after the final threat of frost has passed, extending into early summer. For the Deep South, this can be as early as mid-April, while in Northern states, planting typically begins in late May or early June. Planting can often be successful throughout the summer months, sometimes as late as August, provided there is adequate soil moisture for establishment. Planting later in the summer, such as late June or July, is a strategy often employed to ensure the plot is most attractive and succulent during the early archery season.
Specific varieties, such as Iron & Clay, are commonly used because they produce forage within 45 days and mature seed in about 100 days. This fast maturity rate allows flexibility for planting a second crop or for timing the peak palatability to coincide with the beginning of the hunting season. Selecting a variety well-suited to the local climate will maximize the yield.
Soil Preparation and Planting Techniques
A comprehensive soil test is the first step, providing specific recommendations for lime and fertilizer applications to maximize cowpea health and protein content. Cowpeas thrive in well-drained soils and perform best when the soil pH is maintained between 6.0 and 6.5. Adjusting the pH with lime, based on the soil test results, ensures the plants can efficiently absorb necessary nutrients.
As legumes, cowpeas fix atmospheric nitrogen into the soil, reducing the need for applied nitrogen fertilizer. However, they still require phosphorus and potassium for vigorous growth and nutritional quality. A soil test will specify the exact amounts of these nutrients to apply, often using a balanced starter fertilizer like 0-20-20 or 13-13-13, which should be incorporated into the seedbed before planting.
The cowpea seed must be inoculated with the correct strain of Rhizobium bacteria, typically inoculant code EL, just before planting. This inoculation is necessary for optimal nitrogen fixation, which directly contributes to the high protein levels. Seeds should be planted at a depth of about one-half to one inch, whether drilled or broadcast, to ensure good seed-to-soil contact and proper germination.
Managing Heavy Browse Pressure
The quality that makes cowpeas attractive to deer—their palatability—is also their main vulnerability, as deer often over-browse young seedlings before the plot can fully establish. This heavy pressure can quickly lead to a failed plot, especially in areas with high deer density or small food plots. One effective strategy is to increase the plot size, as plots of at least one acre better withstand concentrated feeding pressure.
Planting cowpeas at a high density, or in a mix with less-preferred companion crops, helps distribute the browsing impact. Companion crops like grain sorghum, Egyptian wheat, sunflowers, or sunn hemp provide physical support for the vining cowpeas, allowing the plants to climb and produce more forage. The taller companion crops provide a structural “ladder” and shield the tender cowpea leaves from total defoliation.
For smaller plots or high deer populations, temporary exclusion fencing is the most reliable method for successful establishment. Using an electric fence system or temporary cages allows the cowpeas to grow for 30 to 50 days until they are robust enough to withstand grazing. Once the plants have developed sufficient biomass, the fencing can be removed, offering deer a lush, mature food source until the first seasonal frost.