Plant Industries

Serving the citizens of Arkansas and the agricultural and business communities by providing information and unbiased enforcement of laws and regulations set by the Arkansas State Plant Board

Cogongrass: A Potentially Invasive Weed in Arkansas

Cogongrass - Imperata cylindrica is a perennial grass native to Southeast Asia.  The grass is a highly invasive species in the United States and other parts of the world outside of its native range.  In this country, it is found mainly in the Gulf Coast and South Atlantic states.  The grass can spread quickly from underground rhizomes and, to a lesser extent, from wind blown seeds.  This can include movement of soil contaminated with rhizomes, spread from dirt moving equipment, and seeds stuck on mowers and vehicles. 

Click here to view the Cogongrass Stakeholders Meeting.

Once established, the grass primarily spreads from the creeping rhizomes, often forming a circular patch.  The grass can grow in sun or shade and is a serious agricultural and environmental pest often invading pastures, tree plantations, wild lands, and riparian areas.  It can form a dense monoculture and outcompete native vegetation.

Identification of grasses can be difficult, but cogongrass has some characteristics that make identification easier.  As a warm season grass, the blades from the previous season persist as tall pale straw-colored leaves.  In spring, the new blades emerge bright green and the fuzzy flower/seed heads join quickly.  There are very few warm season grasses that bloom in spring.  The midribs of the blades are often off center.  Individual blades of grass emerge from below ground and are tightly coiled forming a sharp point.  Most other grasses emerge from clumps at the surface of the ground.

In Arkansas, we have discovered a population in Phillips County, a few miles from the Mississippi River.  This is our first find, and we have been treating the area with a combination of herbicides to kill it out and prevent spread to nearby areas.  We do not know how this started growing here, but there are populations in most of Mississippi. The Arkansas Department of Agriculture and other state and federal agencies will be surveying areas across from Mississippi River crossings, and nearby locations.  If we find any more cogongrass, we will begin control measures on those as well.

There is also an ornamental cultivated variety of Cogongrass – Japanese Bloodgrass and Red Baron.  These have been available in the nursery trade and online.  These are prohibited plants in Arkansas, and many other states because they can revert back to the parent and begin spreading by rhizomes and wind-blown seeds.  Do not purchase, sell, trade, or use this plant in Arkansas.  If you have some in your yard, please contact us and we will work with you to remove the plant(s) and make sure that it has not spread into nearby areas.

More information and photos can be found here: https://www.uaex.uada.edu/publications/PDF/FSA-2161.pdf  If you think you have seen cogongrass, or if you have some Japanese Bloodgrass planted in your yard, please contact us at 501-225-1598 or email caps@agriculture.arkansas.gov.

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