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Green kyllinga (Kyllinga brevifolia Rottb.) is a warm-season, perennial sedge weed common throughout Louisiana. It spreads through seed as well as through rhizomes (underground stems). Green kyllinga prefers low areas with wet soil and is usually an indicator of poor drainage. It forms dense mats and can tolerate low mowing heights, making it a difficult weed to control in turfgrass.
Green kyllinga has fine, narrow, dark green leaves that extend from stems, usually in sets of three. Stems are also dark green and are triangular in cross section. Green kyllinga produces small round- to oval-shaped light green seed heads, which appear pointed and spiky in texture. As seeds mature, seed heads turn brown in color. In addition to seeds, green kyllinga also produces rhizomes (underground stems) that are red to purple in color. It has a low-growing, mat-forming growth habit. For more information on green kyllinga identification and characterization, reference the USDA Plants Database.
Three leaves and triangular stem
Seed head
Rhizomes
The best way to prevent or reduce weed encroachment is to maintain a healthy lawn through proper fertilization and soil pH and regular mowing. Properly maintaining a lawn through these cultural practices promotes dense and vigorous turfgrass, allowing it to better compete with weeds. Poorly drained or over-watered lawns are ideal habitat for green kyllinga. In excessively wet areas, improve drainage and adjust irrigation. Below are the recommended mowing heights and nitrogen fertility rates recommended per turfgrass species. In addition to these lawn care practices, manual removal of weeds may also be necessary.
| Turfgrass Species | Mowing Height | Nitrogen Rate (per 1,000 ft2 per year) |
| Bermudagrass | 1 to 2 inches | Up to 3 pounds |
| Centipedegrass | 1 to 2.5 inches | Up to 2 pounds |
| St. Augustinegrass | 2.5 to 3 inches | Up to 3 pounds |
| Zoysiagrass | 1 to 2.5 inches | Up to 2 pounds |
In addition to cultural practices, herbicide applications may be required to achieve effective weed control. There are several post-emergence herbicides that are effective for managing green kyllinga that is infesting turfgrass. However, it often takes multiple herbicide applications to provide season-long green kyllinga control.
When applying any type of herbicide, you must follow the manufacturer’s labeled directions. For more information regarding pesticides for turfgrass please reference the Louisiana Suggested Chemical Weed Control Guide.
| St. Augustinegrass | Centipedegrass | Zoysiagrass | Bermudagrass | |
| Post-emergence Herbicide Active Ingredients | ||||
| sulfosulfuron | Yes | Yes |
Yes |
Yes |
| trifloxysulfuron | No | No |
Yes |
Yes |
| imazaquin | Yes | Yes |
Yes |
Yes |
| sulfentrazone | Yes |
Yes |
Yes |
Yes |
| bentazon | Yes |
Yes |
Yes |
Yes |
| halosulfuron | Yes | Yes | Yes | Yes |
| thiencarbazone + iodosulfuron + dicamba | Yes | Yes | Yes | Yes |
| thiencarbazone + formafulfuron + halosulfuron |
No |
No |
Yes |
Yes |
| flazasulfuron | No |
Yes |
Yes |
Yes |
| sulfentrazone + metsulfuron | Yes |
Yes |
Yes |
Yes |
| sulfentrazone + prodiamine |
Yes |
Yes |
Yes |
Yes |
For information regarding weed identification and control options please contact your local LSU AgCenter Extension Parish Office.
Download here: Louisiana Home Lawn Series: Green Kyllinga 3624-HH
