Security, coverage, and high-quality forage are key to whitetail management. Provide those features and you’ll immediately improve the hunting ability of your food plots and the frequency with which deer use the space. However, you should also consider crop height, cover screens, protein levels and soil nutrition when choosing warm and cool season plantings. Sunn hemp checks all those boxes.
Sunn hemp is a subtropical, bushy, branching legume native to India that doesn’t get much attention in hunting space, but thrives in the southeast. By no means is this warm-season annual a panacea, but it certainly is an excellent addition to habitat diversity, wildlife safety, protein forage, and soil health. It has been a staple on our farm for seven years.
The thick, imposing cover is my favorite aspect of the legume. Personally, I love losing sight of deer as they cruise through a field. You limit shooting opportunities, but you also absolutely increase daylight movement. You can use a tractor to create openings by cutting draft lanes or keeping an overall lower height. Those goals depend on the size of your plot and the configuration of the booth.
Deer feed on the bright green elliptical leaves and the tender budding tips. The stems will continue to grow after being cut until the first frost, which is usually early November in the Southeast. Once the stem becomes thick and stringy, it is less palatable. The deer will then eat all the remaining leaves up to 3 or 4 feet from the ground.
Not much evidence exists on sunn hemp, but estimated levels of crude protein exceed 25% to 30% according to the National Deer Association. As a comparison, in Food plots for wildlife and early successional plants, Dr. Craig Harper reports that soy offers 36.5%. Crude protein content is imperative for land managers to understand in order to have a healthy, well-balanced herd. For example, the Mississippi State University Deer Laboratory recently published the following crude protein requirements for deer: late gestation needs 12%, a lactating female needs 14-16%, developing of antlers requires 16% and fawns after weaning need 1.5%. years demands 17% to 25%.
Based on these numbers, sunn hemp and soybeans are excellent supplemental food plot options for whitetails. Combined with prescribed burning and early season plowing, you will not only see more deer during the fall, but also improve herd health. The latter should be the ultimate goal of conservationists and land managers. Food diversity will attract more deer to your landscape, especially during high-pressure hunting seasons.
According to Anne C. Randle’s article Sunn Hemp: Forage and Soil-Building Superhero, “Sunn hemp possesses many soil-building characteristics, including high rates of biomass production, more than 20 percent higher than crimson clover, and the hairy pea in research trials. Not only is it resistant to plant root nematodes, it actively suppresses them. In just 60 to 90 days, it can produce 120 pounds of nitrogen per acre and can suppress weeds by up to 90 percent.”
Those are staggering and impressive statistics when seed and fertilizer costs are considered.
Hemp grows well in sandy soils and is relatively drought tolerant, which is a big plus in the Southeast. It also flourishes in warm, humid areas with a heavy taproot and well-formed root system. The legume can minimize soil erosion, conserve water, and recycle plant nutrients from the subsoil to the topsoil.
Depending on your goals, sunn hemp may need more maintenance than most annual food plots, growing about an inch a day to maturity. This is a big difference between soybeans and most warm-season wildlife plantations. It may take the deer a little while to zero in on the hemp, but they will find it the first year. Activity will continue to pick up year after year. On my farm in South Carolina, deer have been hammering the tips of succulent stems since the second year of planting.
I suggest starting with several test sites and evaluating the results before planting in the second year. Using the plant for cover screens is ideal around larger fields or open areas to direct the flow of play. Cowpeas are perfect for blending, as the sunn hemp stems provide structure for the vines to wrap around and spread out.
Early shoots are very attractive to deer and could be a problem if the crop is not established first. Monitor and, if necessary, cordon off plots or add milorganite fertilizer to keep deer at bay until the plant reaches 2 to 3 feet. At that time, the plant will become tolerant to browsing as long as its area receives enough rain. After the season, cut off standing stems and allow organic matter to decompose in the soil bed.