Kikuyu grass (Cenchrus clandestinus) is a warm-season perennial grass widely cultivated across tropical and subtropical regions. Native to the highland plateaus of East Africa, it gets its common name from the local Kikuyu people of Kenya. Characterized by its aggressive, mat-forming growth habit, it was intentionally introduced globally, including to Australia, the Americas, and South Africa, serving dual purposes as both a turf and a forage crop. Its vigor allows it to thrive in diverse environments, but this same trait also leads to aggressive spread outside of cultivated areas.
Identifying Characteristics and Growth Habit
Kikuyu grass is easily recognized by its coarse texture and bright, sometimes yellow-green coloration. The leaf blades are relatively wide (1 to 5 millimeters) and can be softly hairy, often appearing folded along the midrib when emerging. A defining feature is its vigorous horizontal growth, which creates a dense, tough layer of turf.
This rapid expansion is facilitated by a dual system of runners: robust stolons that creep above the soil surface, and rhizomes that extend horizontally underground. The branched stolons quickly colonize bare ground, rooting down at nodes situated at intervals of about five centimeters. Below the surface, the rhizomes form a dense, interconnected root network that can penetrate the soil up to 30 centimeters deep, establishing the plant firmly.
The grass’s reproductive structures are often inconspicuous, reflected in its species name, clandestinus. Its small seed heads are largely enclosed within the leaf sheaths, with only the pollen-bearing stamens or feathery stigmas protruding. This reliance on both vegetative growth and seed production contributes to its reputation for being difficult to contain. The dense matting habit quickly suppresses most other competing vegetation.
Primary Uses in Turf and Agriculture
Kikuyu grass is highly valued in turf management, particularly in high-traffic areas, due to its exceptional resilience and rapid recovery rate. Its aggressive growth makes it an ideal choice for sports fields, golf course fairways, and public parks that endure constant wear. The grass tolerates close mowing and heavy foot traffic, quickly repairing bare patches by sending out new stolons.
This warm-season grass also displays excellent drought tolerance, attributed to its deep and extensive root system accessing subterranean water sources. It retains its color better than many other warm-season varieties during periods of mild cold or light frost, extending its aesthetic appeal. Low maintenance requirements regarding fertility and disease incidence contribute to its popularity in large-scale landscaping projects.
In agriculture, Kikuyu grass is a significant forage crop, particularly in dairy and beef production, due to its high palatability and crude protein content (up to 25% under optimal conditions). The grass tolerates heavy, continuous grazing and trampling by livestock, making it a reliable pasture option. Its fibrous root network is also utilized for soil stabilization and erosion control on embankments and steep slopes where soil loss is a concern.
Management and Control of Aggressive Spread
Controlling unwanted Kikuyu grass presents a significant challenge because its extensive network of rhizomes and stolons allows it to regrow readily from fragments. Simple physical removal, such as hand-pulling or light cultivation, is often ineffective since any small piece of runner left behind can quickly sprout a new plant. In large-scale renovation projects, non-chemical methods like solarization can be employed, which involves covering the area with clear plastic sheeting to heat and sterilize the soil and kill the entire mat.
When managing the grass invading existing lawns, the approach depends on the desired turf type. If the invading Kikuyu is in a mixed lawn, selective control is complex, as few herbicides can target Kikuyu without harming the surrounding turf. Selective suppression is most feasible in certain Couch grass varieties, where specific commercial products may temporarily inhibit the Kikuyu’s growth.
For most other lawn types, like Buffalo or Fescue, there are no selective chemical options, requiring the use of non-selective herbicides. Products containing glyphosate effectively kill the Kikuyu, but they must be applied with extreme precision, such as using a paintbrush or sponge, to avoid contact with desirable grass. Multiple spot treatments are necessary to manage persistent infestations. Consistent maintenance, including deep edging and raising the mowing height of the desired grass, can help suppress the invader’s ability to spread into garden beds and borders.