Cogongrass Threatens Native Species More than Kudzu

CLEMSON — Plant detectives have issued a statewide BOLO for one of the worst weeds in the world. Clemson’s Department of Plant Industry is asking for volunteers to “be on the look out” for cogongrass, an invasive weed that ruins lawns, pastures, golf courses, roadways and natural areas, as well as being a hot-burning fuel for forest fires.

The S.C. Cogongrass Task Force will be conducting a yearly survey May 7-9. Volunteers can sign up at www.clemson.edu/for/cogongrass. The Web site also houses photos and background information.

Last year, hundreds assisted with the effort and found cogongrass in two new counties (Greenville and Williamsburg), and additional locations in Pickens, Allendale and Hampton counties. Plant industry staffers are treating all of the spots volunteers helped to find.

Cogongrass is a perennial grass that grows more than 4 feet tall. The leaves are about an inch wide, have a prominent white midrib and end in a sharp point. Leaf margins are finely toothed and are embedded with silica crystals. The upper surface of the leaf blade is hairy near the base; the undersurface is usually hairless. The flowers are arranged in a silvery, cylindrical, branching structure, called a panicle, up to 11 inches long and 1.5 inches wide.

“This year, we will continue our efforts across the entire state and concentrate in areas where we have found cogongrass,” said George Kessler, a task force leader and professor of forestry and natural resources at Clemson. Major truck routes and all facilities where truck traffic is prominent will get special attention.”

Seeds can hitchhike in truck nooks and crannies, then drop off and spread quickly. Seed can blow up to 15 miles in the wind. Cogongrass has the potential to be far worse than kudzu, a Japanese plant that has spread to 7 million acres in the southern United States.

"Kudzu's a weenie plant compared to cogongrass,'' James H. Miller, research ecologist for the U.S. Forest Service in Auburn, Ala., told an Associated Press reporter in 2003.

Cogongrass used as packing material entered into the United States through the port at Mobile, Ala., in 1912. The USDA planted it purposely for soil-erosion control in Mississippi and Florida in the early 1920s.

Cogongrass is distributed throughout the southern and southeastern United States as far west as eastern Texas. There have been reports of cogongrass surviving as far north as Virginia, West Virginia and Maryland. Florida has the worst problem with it -- more than 1 million acres are infested. South Carolina has only about 10 acres -- so far, says Kessler.

Regional forestry officials are concerned about the potential impact on the multi-billion dollar forest industry, because the grass smothers pine seedlings. For example, cogongrass is estimated to cost Alabama $7.5 million per year in lost forest productivity.

Cogongrass grows on every continent except Antarctica and has taken hold in about 1.2 billion acres worldwide. Asia has lost about 500 million acres to the weed, which spreads to an additional 370,000 acres yearly, according to reports. It listed among the top 10 most destructive invasive plant species worldwide.