South Carolina is being faced with a new invasive plant species that many people feel will be far worse than kudzu or any other plant you can think of. The plant, cogongrass, is considered to be one of the top ten worst weeds in the world. We already have several counties where cogongrass has been found in South Carolina. The Department of Plant Industries at Clemson University is charged with the eradication of this plant and they have treated all reported infestations.
Left unchecked, this aggressive plant forms dense stands over large areas and can virtually eliminate our native plants. Cogongrass is mostly unpalatable to livestock and wildlife, and can create a significant fire hazard.
South Carolina is in the early stage of invasion by cogongrass. We believe we can stop this plant from becoming the complete menace we see in Alabama and Florida. We need your help. We need eyes and ears of people who work outside who can help find this grass and report any sightings. We need you to become aware of unusual plants in the fileds and landscapes you regularly work in. This web site provides you with reference materials and pictures that will aid with the identification of cogongrass. Information, brochures, posters and assistance can be found at the local Clemson Extension Office and the local SC Forestry Commission Office. Please notify these offices or the Department of Plant Industry (864-646-2130) if you think you see the plant in your area.
When cogongrass becomes established the grass will develop as a roughly circular patch that grows larger over time. Most of the spread of the patch is from rhizome growth that continues to explore new areas. The result is a thick patch of grass that crowds out other vegetation and only allows existing vegetation that is taller than cogongrass to exist. Cogongrass is capable of completely dominating the location. |
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Cogongrass first arrived in the United States in 1911 near Mobile, Alabama, as a packing material in shipments from the Far East. In the early 1920's, some people planted it in Alabama, Mississippi, and Florida for grazing purposes. By the 1970's, tens of thousands of acres were infested with Cogongrass. Today, Florida has more than 1 million acres of cogongrass. |
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Seven counties in South Carolina have reported Cogongrass infestations. Multiple spots have been reported in Allendale, Beaufort, Charleston, Hampton and Pickens county. Single spots have been reported in Aiken and Anderson county. All spots have been treated one or more times by the Department of Plant Industry at Clemson University or in the cases of federal land by the agency owning the land. |
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Here we see cogongrass in a pasture, in a typically circular patch. The patch is in the flower stage. If the patch has not been disturbed the flower stage will be from late April through early June. If the patch has been disturbed then flowering can be anytime during the growing season. |
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This aerial view shows many cogongrass patches. Each small circle represents a patch of cogongrass. Without treatment, the patches will grow together and cogongrass will dominate the entire site. |
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Cogongrass can grow in full sunlight and in partially shaded areas. This is a patch of cogongrass in a pine forest. |
| Cogongrass is very competitive and will eliminate all other vegetation and become the only ground cover.This is demonstrated in the pine stands pictured below. From left to right are Cogongrass in a young pine plantation, Cogongrass in a mature long leaf pine stand during the growing season and Cogongrass in a mature pine stand at the end of the growing season. |
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The flower or seed head for Cogongrass contains many seeds that are easily dispersed by wind. In general the seeds from cogongrass have a low viability, reportedly as low as 30 percent. The real problem is the number of seeds that can be produced by a cogongrass plant. Some reports are as high as 30,000 seeds per seed head and as high as 30,000 seeds per plant. |
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There can be thousands of seed heads on an acre. |
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Another method of reproduction is through rhizome growth. Rhizomes can grow four to ten feet per year. Untreated, a ten foot spot can increase in area covered by ten fold in one year. |
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Cogongrass does not have an apparent stem. Leaves appear to rise from near the ground and can look bunch-like. The size of the leaves varies from one foot on poor sites to as tall as six feet on good sites with the average height being three to four feet. |
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For most plants the midrib of the leaf or blade is in the very center of the leaf or blade. The midrib of a blade of cogongrass is offset to one side of the grass blade. This is a general characteristic for cogongrass. However, there are other grasses that have an offset midrib. |
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Cogongrass seeds are easily caught on equipment and can be transported to sites that do not have the grass. States with severe cogongrass infestations are Georgia, Alabama, Mississippi, Louisiana, and Texas. Landowners need to be careful and request equipment coming from these states be sanitized before entering their land. This applies to farm equipment, logging equipment, ATV's and their carriers. |
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Cogongrass will grow in full sunlight and in partial shade. Here we see cogongrass in a pine stand that was recently thinned. Cogongrass in a pine stand creates problems because the grass is not eaten by livestock or wildlife. In addition, cogongrass burns hotter that normal native vegetation and creates problems with the survival of larger plants and in the case of most trees will keep them from becoming established. |
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Cogongrass restricts what will grow on a site and can interfere with pine regeneration. Without effective treatment your pine stand might have only scattered trees as seen here. |
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Cogongrass is very flammable and burns hotter than native vegetation. This fact influences what will survive on a site. |
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A solid field of Cogongrass. |
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This homeowner started with a few cogongrass plants along the house. Cogongrass has taken over the border plantings and is now spreading across the yard. |
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Small patches of Cogongrass can be treated by using a backpack sprayer with an appropriate herbicide. Eradication of the grass will require more than one application. Currently all cogongrass locations except those on Federal lands are being treated by the Clemson University- Department of Plant Industry. Federal lands are being treated by the Federal government. |
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Cogongrass cultivar Red baron. Also known as Japanese Blood Grass
All forms of Cogongrass are banned from South Carolina. There are nurseries in other areas of the county that grow and sell cogongrass. One common cultivar is Red Baron, also known as Japanese Blood grass |
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All of the above pictures are taken from Forestryimages.org |
| SC Tree Farm DEV |
