Green kyllinga
Kyllinga spp.
A low-growing perennial sedge resembling fine turf, forming dense mats in wet areas.
Identification
Green kyllinga (Kyllinga brevifolia) is a perennial sedge with a low, mat-forming habit and dark green, narrow, grass-like leaves usually only a few inches tall. Like other sedges it has a triangular stem (sedges have edges), distinguishing it from true grasses. Its most diagnostic feature is the seedhead: a single round to oval, green, spiny-looking flower cluster sitting just above the foliage, subtended by three long, narrow leaf-like bracts that radiate beneath it. The dense, low mats, dark-green color, and round green seedheads with three bracts set green kyllinga apart from nutsedge, which is taller, more upright, and has yellow or purple seedheads.
Symptoms & Damage
Green kyllinga degrades the stand by forming dense, dark-green, low mats that crowd out turfgrass and create patches that differ in color and texture from the surrounding lawn. Because it tolerates close mowing and wet soils better than many turfgrasses, it can dominate damp, low areas and persist as conspicuous mats studded with round seedheads, disrupting uniformity and playability. The aggressive rhizome spread lets infestations enlarge steadily, thinning and displacing desirable turf.
Biology
Green kyllinga is a perennial sedge that spreads aggressively by rhizomes and also reproduces by seed, with each round seedhead composed of many tiny flowers that can each set seed. The rhizomes allow it to form dense, expanding mats and to regenerate after top growth is removed, which is why mowing and hand-pulling alone rarely eliminate it. It is most active in warm weather and persists year to year through its rhizome system, making the below-ground network the key target for control.
Occurrence & Spread
Green kyllinga thrives in poorly drained, frequently wet, or over-irrigated turf and is well adapted to close mowing, often dominating where turf is cut at an inch or less. It is most prevalent in the warmer southern United States but has spread into cool-season turf as well, invading low, damp areas, drainage swales, and chronically moist sites. Wet conditions and tight mowing give it a strong competitive edge over many turfgrasses, so correcting drainage and irrigation is central to limiting its spread.
Favorable Conditions
Wet, poorly drained, over-irrigated sites in summer.
Cultural Management
The most important cultural step is to correct the wet conditions that favor it by improving drainage and reducing excessive irrigation, which removes the moisture advantage green kyllinga depends on. Maintaining a dense, vigorous stand and, where feasible, raising the mowing height reduces its competitiveness, since it is so well adapted to close mowing. For small, well-defined patches, physical removal with a sod cutter that lifts the rhizome mat can be effective, but any rhizome fragments left behind can regenerate the colony.
Further Reading
University extension resources — open in a new tab.
Related Reports
No published reports yet for this pest.
Reports will appear here as they are peer-reviewed and published.