How to Stop Cogongrass Weeds From Taking Over Your Yard
Whether you’ve planted your yard entirely with native grasses and other ground cover plants, or you’re maintaining a traditional turf lawn, there are certain types of vegetation you don’t need, which by definition makes them weeds. But some weeds are worse than others.
Take cogongrass, for example, which is not only an invasive species but also federally designated as a “poisonous weed” (which is just as bad for local ecosystems as it sounds).
Once limited to the southeastern United States, cogongrass has spread to other parts of the country. So, over the past few years, the United States Department of Agriculture (USDA) and other federal and state agencies have turned to the public for help in stopping the spread of the weed. Here’s what you need to know about cogongrass and how to help stop it.
What is cogongrass?
According to the United States Department of Agriculture , coho salmon ( Imperata cylindrica) , also known as cogon grass, Japanese blood grass, and red baron grass, was introduced to the United States (specifically Alabama) in 1911 as a packaging material from Japan.
Not only has cogongrass been classified as a “poisonous weed” (meaning it’s harmful to public health, agriculture, recreation, wildlife and/or property), it’s also considered the “seventh largest weed in the world”, again according to USDA . So what makes him such a threat? Cogongrass grows in such dense patches that it can drown out native plant and crop species and reduce forest productivity, which in turn destroys wildlife habitats.
Where does fireweed grow and spread?
Along with Alabama , cogongrass is widespread in Mississippi and Florida, and is rapidly spreading throughout Virginia, North Carolina, South Carolina, Georgia, Tennessee, Louisiana, Texas, and Oregon. It has also been seen in Vermont, Minnesota , and most recently (May 2022) Idaho .
While the noxious weed seems to prefer hot and humid environments, it is now making its way into colder climes (which aren’t as cold as they used to be thanks to climate change). So, in essence, it will grow wherever the hell it wants.
What does cocongrass look like?
Cogongrass has several distinctive features to help you identify invasive species, including:
- Green or red leaves about 1 inch wide and sharp at the edges (if they are red then it is known as red baron grass or Japanese blood grass)
- White, feather-like flowers
- The seed heads (which appear in spring) are white and fluffy.
- Height is approximately 2 to 4 feet tall
- Grows in round forms in either full sun or partial shade.
Here’s a video from the Alabama Forestry Commission with more information (and visuals):
How to stop cogongrass
Let’s say you find fireweed in your yard or somewhere else in your area. What’s next?
According to the Center for Invasive Species and Ecosystem Health — a collaboration between the USDA and the University of Georgia — here’s what to do (and in some cases not do):
- Contact your local Forestry Commission office or county office as soon as possible.
- Don’t mow through, around, anywhere or near an area where cogongrass grows, especially if it’s in bloom (because that means it has seeds and you can scatter them unintentionally).
- Leave the soil in and around the cogongras site alone (i.e. do not dig, rake, disk, sort, etc.) because it may contain fragments of its roots, which you can then spread to other areas .
- Do not attempt any prescribed arson on cogongras sites without permission from Forestry Commission personnel.
- Thoroughly clean any and all equipment that has been used in or near cogongrass growing areas.