A Low-maintenance Lawn Grass for the Deep South
Common carpetgrass was introduced into the United States through New Orleans during the early 1800s. The Creole citizens of New Orleans referred to it as “Louisianagrass” or “petit gazon” meaning “small lawngrass.” Carpetgrass adapted well to the southeastern coastal plains near the Gulf of Mexico, growing in a wide variety of soil textures ranging from infertile sands to imperfectly drained clays. Carpetgrass has also been referred to as “native pasture grass” because of its ability to grow in infertile pastures where other grasses do not thrive. Interest in common carpetgrass as pasture grass peaked during World War II when agricultural fertilizers were limited.
Although carpetgrass was distributed throughout Louisiana in the 1940s as a pasture grass, there had been little research on the use of carpetgrass as a lawn turf. St. Augustinegrass is predominately grown in Louisiana’s southern parishes where temperatures seldom drop below 32 degrees F, while centipedegrass is commonly grown in the northern parishes where temperatures more frequently dip below freezing. Zoysiagrass and bermudagrass are rarely used as lawn grasses because of the increased cultural practices and equipment required. Common carpetgrass is an alternative low maintenance lawn grass well suited to Louisiana’s warm, moist climate. Research at the LSU Agricultural Center has been uncovering information that indicates common carpetgrass is suitable for growing on lawns in all 64 parishes of the state.
Common carpetgrass is often mistaken for St. Augustinegrass or centipedegrass (Figure 1). Common carpetgrass is a perennial creeping grass that forms a dense sod, with light green, coarse-textured leaf blades. The color and texture of carpetgrass leaves are similar to centipedegrass. Leaves of common carpetgrass are short, blunt-tipped, smooth and folded in the bud. The prominent seedheads of carpetgrass are an easy way of distinguishing it from other lawn grass species (Figure 2). Seedheads typically range in height from 6 to 12 inches. Centipedegrass and St. Augustinegrass seedheads are shorter and less conspicuous.
Carpetgrass adapts to wide soil types and pH ranges (4 to 7). It can easily be established from seed, sprigs or sod. Planting 1 to 2 pounds of pure, live seed per 1,000 square feet from June 1 to September 1 in Louisiana is a rapid and inexpensive way to establish a lawn. Commercially packaged seed mixtures of common carpetgrass and centipedegrass are being sold throughout the Gulf Coast region. Common carpetgrass germinates and establishes quickly, reducing the potential of seed washing and erosion. Soaking carpetgrass and centipedegrass seed in distilled water at room temperature 48 hours before seeding can reduce germination time by at least two days.
Nitrogen requirements are low compared to other warmseason lawn grasses. According to AgCenter research, quality carpetgrass lawn can be maintained by applying between 2 to 4 pounds nitrogen per 1,000 square feet per year and mowing weekly at 1.5 to 3 inches with a rotary mower. Mowing weekly will control tall seedheads associated with common carpetgrass. Application of newly developed plant growth regulators (PGRs) and herbicides with PGR attributes can chemically reduce seedhead production and vegetative growth and increase turfgrass quality.
Comparatively, common carpetgrass has fewer pest problems than most warm-season lawn grasses. This is essential in Louisiana where disease and insect pressures are high. For example, brown patch (Rhizoctonia solani) is often associated with large circular brown patches in St. Augustinegrass lawns during the spring and fall. This is less of a problem with common carpetgrass. Insects are also less of a problem with common carpetgrass. However, the best protection against pests is scheduled fertilization and irrigation.
Common carpetgrass is one of the only turfgrass species recommended for wet sites. It often is found growing in areas with high water tables where other grasses cannot grow. Ag Center research has shown that carpetgrass can survive up to six weeks of continual soil waterlogging. This is essential in the Gulf Coast region of the United States where heavy rains and tropical storms can result in frequent soil waterlogging.
The low maintenance aspects of common carpetgrass, pest resistance and its adaptability to moist soil conditions make it a desirable turfgrass species not only in Louisiana but in the southeastern coastal plains of the United States.
(This article was published in the winter 2000 issue of Louisiana Agriculture.)