Pennisetum clandestinum is a rhizomatous grass native to the highlands in Eastern Africa. It reproduces by underground rhizomes, above-ground runners, and seeds, forming dense mats.
It is easily identified by its short, coarse-textured leaves, densely hairy sheath, and profusely branched stolons.
Common Kikuyu Grass Classification
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Monocotyledonae
- Order: Cyperales
- Family: Poaceae
- Genus: Pennisetum
- Species: Pennisetum clandestinum
- Common Names: Kikuyu Grass
Nativity and Distribution
Common Kikuyu Grass is native to the highlands of Eastern Africa in countries including Kenya, Tanzania, Rwanda, Burundi, and the Democratic Republic of Congo.
Today, the grass is naturalized in many regions across the globe such as Asia, Australia, South Africa, and the Southern United States.
Physical Characteristics
- Leaves: Flattened or upwardly folded, bright-green, short leaves
- Stems: Thick with 5-cm interval internodes and a single blade and leaf sheath
- Flowers: A spike bearing 2-4 spikelets with short bristles at the base
- Roots: Fibrous root system
Pennisetum clandestinum is a rhizomatous perennial grass that forms dense and hardy mats of turf. It reproduces by underground rhizomes, above-ground stolons, and seeds.
It is easily identified by its short, coarse-textured leaves, densely hairy sheath, and profusely branched stolons.
Common kikuyu grass leaves are glabrous or finely haired, folded at initial growth, and flat when mature. The leaf blades are 15 cm long and 3-5 mm wide, blade-shaped, and obtuse at the apex.
The stolons are 40 cm long, heavily branched, and have internodes at intervals of 5 cm, with a single sheath and blade. Rhizomes occur at a depth of 20-30 cm in the soil and have similar physical traits as the stolons but without expanded leaves.
The grass produces its inflorescence as a spike with 2-4 spikelets with 2 florets enclosed in the upper sheath.
The seeds are 2 x 1.5 mm and dark brown in color.
Reproduction, Dispersal, and Life Cycle
- Life Cycle: Perennial
- Seeds: Produces one seed per spikelet
- Climate: Warm sunny climates
- Dispersal: Water, animals, and contaminated implements and vehicles
P. clandestinum behaves as a perennial grass and thrives in warm and sunny climates. It mainly reproduces vegetatively by underground rhizomes and above-ground stolons.
The rhizomes occur 20-30 cm in the soil and produce fibrous roots that can go deep up to 3 meters. The runners produce shoots from their nodes, creating dense mats along the ground.
Kikuyu grass also reproduces through seeds, which are dispersed by animals, water, and contaminated implements and vehicles. They can also get dispersed to longer distances as a contaminant of crop seed. The seeds hidden in the soil remain viable for more than ten years.
Similar Plants
- Pennisetum villosum
- Paspalum vaginatum
- Paspalum distichum
- Cynodon dactylon
- Digitaria abyssinica
Uses
- It is a valuable pasture grass in many countries like Colombia, Hawaii, and South Africa, due to its high tolerance to heavy grazing.
- It is a highly valued turf grass for ornamental and sports uses like residential lawns and golf courses because of its bright green foliage.
- The grass is used for weed suppression, land reclamation, and soil erosion efforts.
Impact on Farms and Environment
Pennisetum clandestinum is a serious weed in many countries and has been named one of the 100 worst weeds as well as a federal noxious weed in the USA.
While it is a useful fodder grass, its aggressive growth can make it invasive in many settings. In farms, it can compete for natural resources with desirable plants, leading to crop losses. It has also been observed to have an allelopathic effect on tomato plantations.
Common kikuyu grass can invade natural habitats causing the decline of native species diversity as recorded in New Zealand, South Africa, and the Galapagos Islands.
It can also invade lawns and cause blockages and access limitations in irrigation channels, roadsides, and industrial areas.
While it may provide valuable pasture, it can cause poisoning in livestock, especially sheep if grown under highly fertile conditions or infected by fungi.
Control
- Cultural control: Growing clovers in pastures or legumes in crop farms to reduce the spread of the grass.
- Chemical control: Herbicides like fluazifop-butyl and glyphosate for crop farms and MSMA + triclopyr for turf grasses.
The grass has deep rhizomes, making it difficult to eradicate without heavy tillage equipment. However, in pastures, growing clovers and combining them with heavy grazing, forage harvesting, or mulching can help control the grass.
A legume fallow in a maize plantation has also been documented as helpful in reducing the weed. Plastic mulches are often used to control the grass in ornamental nurseries.
For larger infestations, selective and non-selective herbicides like fluazifop-butyl, bromacil, and glyphosate can be used depending on the crop variety and season. We recommend consulting a local expert to get the best herbicide for your crop.
Herbicides such as MSMA, bensulide, or combinations such as MSMA + triclopyr are recommended for use on turf grass against common kikuyu grass.
Lead Editor for Insight Weeds.