Imperata cylindrica
More Info & Photos of Cogongrass
Non-Herbicide Management Options
1. Physical Management Options
Cogongrass can be mowed, grazed, or burned, but it is difficult to control physically because it will propagate from stem fragments or the roots. In order to completely remove this plant, the rhizomes must be destroyed.
Deep plowing may be effective in the removal of cogongrass if the plow reaches up to 6 inches deep.
2. Biological Management Options
At this time, there are no known biological controls for cogongrass.
Herbicide Control Options
Always read the product label for directions and precautions, as the label is the law. Click on the name of the product to see the label. Read the label for specific water use restrictions.
The active ingredients that have been successful in treating this plant include:
- Imazapyr
- Glyphosate
1) Imazapyr
The active ingredient, imazapyr, inhibits the plant enzyme AHAS (acetohydroxyaced synthase). Habitat is a systemic herbicide that is effective on post-emergent floating and emergent aquatic vegetation. Imazapyr is effective at low-volume rates and does not contain heavy metals, organochlorides or phosphates, making it safe to humans and livestock. Habitat requires the use of a spray adjutant when applying on post-emergent vegetation.
Common trade or product names include but are not limited to:
2) Glyphosate
Liquid glyphosate formulations have been effective on cogongrass above the water line, but ineffective on plants in the water. They are broad spectrum, systemic herbicides. Systemic herbicides are absorbed and move within the plant to the site of action. Systemic herbicides tend to act more slowly than contact herbicides. An aquatically registered surfactant (see the label) will have to be added to the glyphosate solution for good results.
Common trade or product names include but are not limited to:
Precautions
One danger with any chemical control method is the chance of an oxygen depletion after the treatment caused by the decomposition of the dead plant material. Oxygen depletion can kill fish in the pond. If the pond is heavily infested with weeds, it may be possible (depending on the herbicide chosen) to treat the pond in sections and let each section decompose for about two weeks before treating another section. Aeration, particularly at night, for several days after treatment may help control the oxygen depletion.
One common problem in using aquatic herbicides is determining area and/or volume of the pond or area to be treated. To assist you with these determinations see SRAC #103 Calculating Area and Volume of Ponds and Tanks.
Many aquatically registered herbicides have water use restrictions (See General Water Use Restrictions).
To see the labels for these products click on the name. Always read and follow all label directions. Check label for specific water use restrictions.
Cultivation Options
Cogongrass is non-native to the United States. It is very invasive plant that should not be propagated. Non-native plants threaten the native organisms in an area. They may alter the food chain and/or push their native competitors out of the area.
This plant is not native to North America, but has naturalized in much of the United States. While it is not illegal to possess this plant in Texas, it should not be introduced into new water bodies and should be treated with herbicide when present.
Questions?
If you need assistance, contact the Ag & Natural Resources agent in your county or hire a professional.