Consider Warm-Season Grasses for Wildlife

Planting native warm- and cool-season grasses may be quite beneficial for wildlife species, including whitetail deer.

By John S. Powers

Hunters have a bit of a love-hate relationship with grass.

Those who plant warm-season plots (corn, sorghum, millet, beans, peas, etc.) for the benefit of wildlife fight, to some degree, the same battle as row croppers and gardeners. For those who plant fall and winter plots (usually to feed and/or attract deer for harvest) cool-season grasses are their bread and butter whether they are planted alone or in combination with other cool-season species.

Indiangrass is one of many native warm-season grasses recommended for providing benefits to multiple wildlife species. (Photo: Jennifer Anderson/USDA-NRCS PLANTS Database)

For the most part, planting grass that grows primarily in spring and summer months has been done by stock ranchers and homeowners. Recently, however, another group of grasses, specifically, native warm-season grasses, has begun to be recognized as a valuable alternative to commonly-planted, introduced, cool-season turf and forage grasses (Bermuda, bahia, fescue, orchardgrass, ryegrass, etc.) for erosion control, livestock grazing, and production of hay. Planting native warm-season grasses should be strongly considered where wildlife is a priority.

Native warm-season grasses are indigenous to North America, not only to the Great Plains but also to eastern portions of the continent. Warm-season grasses most commonly found in the eastern United States include switchgrass, coastal panicgrass, big bluestem, little bluestem, Indiangrass, deertongue, purpletop, Eastern gammagrass, sideoats grama, and the cordgrasses. These grasses range from 1½ to 8 feet tall.

When the first European explorers and settlers arrived in what is now the eastern United States, significant areas of mixed grasslands were found scattered throughout the forests. These tracts primarily were associated with rocky outcrops, barrens and areas that burned frequently (especially in the fire-maintained pine forests of the Atlantic and Gulf Coastal plains). Over time, however, these grassy tracts dwindled as a result of changes in land use and a preference for turf grasses as livestock forage and erosion control. Now, remnant areas of native grasses are most often found in coastal areas, on barrier islands, in railroad and utility right-of ways, and in natural areas along major river systems.

A longtime bias has existed toward the use of cool-season turf and forage grasses for erosion control, grazing and hay production. This preference is largely based on the fact these grasses are readily available, relatively inexpensive, and typically exhibit good seedling vigor, which allows fast and easy establishment (especially important in stabilization of areas at risk of erosion). Additionally, these grasses can be sown at almost any time of the year outside the hottest, driest part of the summer without the need for specialized equipment or particularly intensive site preparation.

Conversely, native warm-season grasses tend to be more expensive and sources of seed can be more difficult to locate, especially for regionally adapted varieties. The window for planting native warm-season grasses is much narrower, ideally limited to the early spring, although late fall/winter plantings may be successful on droughty soils with little established competition.

Planting care

Considerably more attention must be paid to site preparation prior to planting these grasses because they are intolerant of heavy weed competition (including that of other grasses). Competing vegetation should be killed using appropriate herbicides prior to planting native warm-season grasses.

After elimination of competition, seeds may be planted on a conventionally prepared (tilled, disked, cultipacked, etc.), bare, firm seed bed then covered to a depth of 1/8- to 1/4-inch by cultipacking or very light disking. If seed is to be planted using a seed drill, specially-made drills must be used for many species of native warm-season grasses because their “bearded” or hairy seeds quickly clog conventional drills. Seed can be drilled among existing (dead) vegetation if its height is reduced using some combination of fire, mowing and raking.

Finally, patience is required where establishment of native warm-season grasses is concerned. Seed germinate late in the spring and grow slowly above ground during their first growing season while resources are allocated to establishing deep, strong root systems.

Despite difficulties involved in their initial establishment, native warm-season grasses have advantages that outweigh their disadvantages. These include the aforementioned deep, well-developed root system. Though its establishment results in slower initial growth, once in place this root system forms a tight sod unequalled in holding soil, thus preventing erosion.

The relative depth of this root system makes warm-season native grasses much more drought tolerant than cool-season turf or forage grasses. This not only permits them to survive the dry conditions of late summer, but also allows them to continue to produce forage for grazing livestock and/or hay for winter use during a period largely unproductive for cool-season grasses. Native warm-season grasses have been found to be more palatable and produce higher weight gain in livestock than some more traditional forage species.

Wildlife benefits

In addition to the advantages they provide to the farmer, native warm-season grasses provide numerous benefits for wildlife.

Most cool-season turf and forage grasses produce stems that grow in dense, homogenous stands at ground level, and, once established, provide relatively little diversity with regard to species composition and stand structure. These dense stands are difficult if not impossible for small game species (quail, rabbits and turkey in particular) to move and forage through, and without considerable manipulation, they provide little of the specialized structure needed by ground-nesting birds for reproduction.

On the other hand, mixtures of native warm-season grasses managed with mid- to late-summer fire at 2- to 3-year intervals provide excellent wildlife habitat. The stems of these grasses grow in tight distinct clumps at ground level. This growth form provides a relatively open vista at ground level, even among seemingly dense stands, which allows small game to readily move among the grass clumps. Periodic fire keeps the litter layer between clumps of grass relatively light and provides suitable habitat for ground-nesting birds.

Seeds produced by the grasses and other associated plants are easily accessible on the relatively open ground. Foraging for insects, abundant in the spring and summer, by hatchling quail and turkeys is unimpeded. The diversity in height reached by various species in a stand provides nesting habitat for numerous song birds while the taller species provide excellent escape cover for a host of small prey species.

Grass: love it or hate it. Mow it, disk it, spray it or burn it. But, choose carefully when planting it.

John S. Powers is an Area Wildlife Biologist with the Alabama Division of Wildlife and Freshwater Fisheries.