Native to: southern Europe, Africa, and SE Asia
A warm-season perennial grass considered among the worst invasive plants in the world. In the US, it is established in Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Texas, and Oregon. It was first accidentally introduced in the United States near Mobile Alabama in 1912 via crate packing material and subsequently intentionally introduced from the Philippines into Mississippi as a forage crop in 1921. Plants from Mississippi were replanted in Florida for forage and soil stabilization in the 1930s though it proved to be an inadequate forage. Thriving in fine sand to heavy clay and doing well in soils of low fertility it infests ditch banks, pastures, road sides/right-of-ways, golf courses, and forests. In central Florida, monocultures of Cogongrass have become established on hundreds of acres of reclaimed phosphate mining areas.
Habit: a tall (2-5 ft.) perennial grass.
Leaves: bright yellowy-green, leaf blades have a midvein which is clearly offset to one side, and serrated (toothed) edges
Rhizome: hard, scaly, and cream-colored with sharply pointed tips
Seeds: fuzzy, white, and plume-like
Distribution in Florida: reported from all 67 counties
Cogongrass spreads rapidly in situ via rhizomes. It has been spread throughout the Southeast by the movement of dirt and soil containing rhizome fragments and by seeds which are carried via wind, water, animals, and equipment. Seed viability is significant in north Florida and other states of the Southeast; however, there are no confirmed cases of viable seed production in central and south Florida. Its agricultural and environmental impacts are severe. In some cases it has completely over taken pastures becoming the only species present and it is very costly to manage. In natural areas, it not only creates dense monocultures reducing biodiversity, but it also drastically alters the fire regime by burning much hotter and faster than natural fire on the landscape. The fuel load also threatens homes and other structures through increased wildfire risk.
Decontamination of equipment is critical.
Mow or prescribed burn prior to herbicide application to remove built-up thatch and promote active growth herbicide uptake. Do not mow when seed heads are present. Do not burn without a follow-up herbicide treatment.
Repeated disking and deep plowing have been shown to be effective in suppressing or eradicating Cogongrass in intensive agricultural settings, but these practices are impractical in many habitats such as forests or natural plant communities
Research is ongoing, but no suitable agents have been identified at this time.
Control of Cogongrass requires an integrated and well-timed strategy which includes herbicide application. Detailed management strategies can be found in the Biology and Control of Cogongrass in Southern Forests and Cogongrass Biology, Ecology, and Management in Florida Grazing Lands