(Imperata cylindrica) is an aggressive
colony-forming perennial grass, often
forming circular infestations.
Grass is 1-5 ft. tall, often leaning into
mats when over 3 ft. tall, tufts of long
leaves, yellow-green, blades with off-center
midvein, silver plumed flowers and seeds in
spring, arising from sharp-tipped
white-scaly rhizomes. Flowers in Alabama
from February - May. Brown oblong seeds
appear May-June and are released within
silvery hairy husks for wind dispersal.
- Cogongrass Interactive Map
johnsongrass (Sorghum halepense),
purpletop (Tridens flavus), silver
plumegrass (Saccharum alopecuroides)
and sugarcane plumegrasses (S.
giganteum), but none have the
off-centered whitish midvein and no
Grows in full sunlight to partial
shade, and can invade a range of
sites. Aggressively invades
rights-of-way, new forest
plantations, open forests, old
fields and pastures. Colonizes by
rhizomes and spreads by
wind-dispersed seeds. Rapidly
growing and branching rhizomes form
a dense mat enabling it to exclude
most other vegetation. Burns
extremely hot, especially in winter,
and promoted by burning. Absent in
areas with frequent tillage.
Why is it a problem?
Cogongrass is one of the 10 worst weeds in the
world. It is steadily marching through Alabama and into neighboring states.
This highly invasive pest permanently alters plant and animal communities,
increases fire frequency and intensity, and requires extensive investment to
control. In other areas of the world cogongrass has destroyed entire
landscapes, creating a ‘sea’ of cogongrass with no other plants. Domestic
food and fiber supplies are negatively impacted by cogongrass through
reduction in wildlife food sources and killing or injuring valuable cash
crops such as corn, cotton, and trees. Cogongrass exists on rights-of-way,
forests, and agricultural, residential, commercial, and industrial areas.
Because it is found in so many areas, there is a need for a large-scale,
concerted effort to effectively control it.
How is it treated?
Currently the most effective approach to
controlling cogongrass infestations is with repeated chemical application,
sometimes over several years. There are numerous herbicides on the market
currently labeled for cogongrass.
latest in cogongrass treatment please read
the following papers written by
Dr. Jim Miller, USDA Forest
Service R&D, Auburn University,
and Dr. Stephen F. Enloe, Auburn
How do I figure out if I have it on my property?
There are several ways to know if cogongrass is
either on your property or a potential threat. First, know how to identify
it by going to www.cogongrass.org/cogongrassid.pdf and downloading the field
guide. If you prefer you can contact your county forester, extension agent,
land manager, or natural resources expert to arrange for them to make the
Where can I get more information?
There are many sources of information about
cogongrass on the internet. Public agencies are a good clearinghouse.
AFC Cogongrass Viewer - Alabama
Forestry Commission’s updated map of current cogongrass
infestations in the
Cogongrass Field Guide
How to Identify Cogongrass - (video)
Stop Cogongrass Hitchhikers
Cogongrass Control In Longleaf Pine
Cogongrass Control Recommendations
Alabama Invasive Plant Council