Gerald Almy: Sunn hemp great new food plot seed

Gerald Almy

For summer food for wildlife you can’t go wrong by growing soybeans. What the deer don’t eat, you can sell as a valuable cash crop when the beans ripen, or leave on the ground as a late-season attraction for all forms of wildlife when the snows fall.

But if you’re looking for something fresh and exciting to draw whitetail deer and other game and non-game wildlife to your property, or keep them on your land, consider a new offering taking the food plot world by storm – sunn hemp. While it’s new to the world of wildlife plots, sunn hemp itself is decidedly not new. In fact, it originated in India around 600 B.C!

In spite of that longevity, few wildlife land managers know much about it or have tried it. You’ll definitely have something unique to offer the local deer herd if you plant a field or plot of this ancient legume. Extensive research shows it to be a terrific seed to put in the ground for wildlife and also an excellent soil builder and soil rejuvenator. This is my third season growing sunn hemp and I’ve been extremely impressed by the results I’ve obtained.

According to the U.S. Department of Agriculture, sunn hemp has been tested in our country since the 1930s and has shown extensive benefits for soil. It also grows better as a cover crop on poor quality soils than many other plants.

It’s used extensively in many countries, especially Brazil, as a soil improvement and green manure crop because of its ability to produce large amounts of biomass in as little as 60 days. “Because of this, it has the potential to build organic matter levels and sequester carbon,” the USDA says. “Also, as a legume it can fix large amounts of nitrogen. Used as a cover crop, sunn hemp can improve soil properties, reduce erosion, conserve soil water, and recycle plant nutrients.” They add that it is also resistant to root-knot and harmful nematodes, and may ultimately prove useful as a biofuel crop.

The ability to restore nutrients to the soil makes sunn hemp especially appealing. It’s a great crop to plant in summer to add nitrogen before a fall planting of wheat or oats, which can then utilize that nitrogen.

It’s been shown to produce up to 134-147 pounds of nitrogen per acre after just 60 days. Even if a winter crop isn’t grown, a large portion of this nitrogen will remain for corn, soybeans, or other plantings in spring.

It also draws up to the topsoil from the subsoil 10-20 pounds of residual phosphorous and 80-160 pounds of potash per acre, while creating four tons of organic matter per acre.

Sunn hemp can be planted any time after frost danger is gone, but grows best when the soil temperature is 65 degrees or higher. The first heavy frost will kill it in fall, much like soybeans.

Once the soil heats up, sunn hemp grows quickly. It can reach 4-6 feet tall in just two months. One strong advantage it has over other warm season summer annuals such as soybeans, cowpeas, and lablab is that it’s resistant to heavy early browsing by deer. That can often kill those other more vulnerable plants. But sunn hemp just keeps growing back.

In fact, sunn hemp grows so fast it’s recommended that it be cut back to 12-18 inches after it reaches 5-6 feet because the stem can become chewy and fibrous. The new tender leaves that emerge will be more appealing to deer. Left uncut, it can reach 10-11 feet!

As you can imagine, this makes sunn hemp very appealing to deer for cover as well as food. Some animals will simply bed down in it and get up to eat during the summer. It’s also great cover for quail and pheasants, providing cover and lots of insects for the birds to feed on. For agricultural purposes, goats also do well grazing on sunn hemp.

Cost for seed can range from $2-6 per pound, depending on the source and quantity you buy. I’ve seen seeding rates vary in recommendations from 15-40 pounds per acre, so this is not an inexpensive plant, but it is not prohibitively costly, either.

When you consider that its protein level is 30 percent, its benefits to deer should be outstanding. Sunn hemp is also a tremendous weed suppressor and eradicator, both shading them out and releasing glucosinolate chemicals that kill many noxious weeds.

Plant sunn hemp by drilling or broadcasting and cover ¼-1 inch deep. It does best on well-drained soils, rather than wet areas. The pH does not have to be high. Over 5.5 is fine.

This plant is excellent for mixing with other crops such as soybeans, lablab and cowpeas. It will divert some early browsing pressure from deer, allowing them establish well, and also provide stalks that these plants can “climb” as they grow, providing increased yield.

This is an exciting “new” food plot seed that wildlife managers and farmers may want to experiment with more extensively. It is sold by several sources that you can locate with a quick internet search. A few I’ve checked out include Hancock Seed Company, Tecomate, Turner Seeds, and Petcher Seeds. I’m sure there are others.

You can also expect many more wildlife seed companies to be offering straight sunn hemp or this intriguing legume mixed with other food plot plants in coming years. Just last year the North American Whitetail Institute began including it in their Power Plant warm season annual mix, in place of sorghum.