Warm-season grasses ready for autumn care

By their very nature, native grasses are suited to survive year-to-year in their native environs. But that doesn’t mean there aren’t a few things the calendar-minded pasture manager can’t do to help maximize a land’s potential.

Dirk Philipp, associate professor of animal science for the University of Arkansas System Division of Agriculture, said perennial warm-season native grasses, such as big bluestem, indiangrass, and eastern gamagrass are very good forages with a sufficient degree of nutritive value that can be grazed between mid-April until the end of August, but no grazing should occur after early September.

“Native warm season grasses substantially reduce their growth during shortening days in the fall and go fully dormant with freezing temperatures,” Philipp said. “Since these grasses are very tall and generate substantial amounts for senesced material, managing the thatch can be challenging.”

Philipp offered some pointers and recommendations to go about bringing native grasses through the winter and to ensure lush regrowth in spring, including burning, grazing management and bush-hogging.

“Burning is by far the most efficient method of minimizing the amount of thatch prior to regrowth in spring,” he said. “These grasses are well adapted to burning and ecologically the best method of managing senesced material. Burning should occur sometime short before green-up, such as early to mid-March in the case of Arkansas.”

Philipp recommended that pasture managers seek help and advice before burning though, as local regulations may apply.

With regards to grazing management, Philipp said that senesced material—grasses that have deteriorated with age—can actually be grazed during the wintertime.

“Cattle will graze of large parts of the dead leaf material if they are supplemented, or have access to other forages as well to maintain nutritional needs,” he said.

Bush-hogging can be done before green-up, as well in February or early March the latest. Removing senesced material earlier may compromise temporary habitat for wildlife, so pasture managers should be careful not to rush this step.

“Bush-hogging requires on-pasture traffic and diesel, so keep in mind this is less desirable than burning, simply from a sustainability standpoint,” Philipp said. “When bush-hogging is necessary, go slowly to chop up everything, to avoid covering regrowth.”

Philipp also recommended removing all dead material from pastures in the fall and winter, to ensure lush regrowth during spring. By monitoring the grasses over the years and making incremental adjustments as necessary, it’s possible to maintain stand biomass and quality. Grazing, Philipp said, may need to be deferred more in some years than in others.

“Last but not least, try to keep travel across native warm season grasses to a minimum,” he said. “Every so often, pickup travel can seriously damage the grass sod, any time of the year.”