Carpetgrass (Axonopus affinis or A. compressus) is a creeping, warm-season grass native to the West Indies, which was introduced into the United States early in the 1800s. Carpetgrass is also called Louisianagrass and has become naturalized in the Southeastern states, especially on poorly drained soils. Carpetgrass spreads by stolons and appears similar to St. Augustinegrass and centipedegrass except for its lighter green color and distinct wavy leaf margin. It has poor cold, drought and wear tolerance, with only fair shade tolerance. Carpetgrass produces tall, unsightly crabgrass-like seed heads throughout the summer, giving the turf a ragged, unmown appearance. Like centipedegrass, carpetgrass grows best on acidic (pH 5 to 6) soils. It tolerates wet, poorly drained soils very well. It often becomes established in these locations, and then escapes to other sites.
Carpetgrass grows on wet soils where few other grasses persist, and has moderate shade tolerance. It is low growing and produces a dense turf with good color when fertilized. Carpetgrass also can be grown from seed.
Carpetgrass will not survive on very dry soils unless infrequently irrigated. Roots tend to be very shallow, so this grass has poor drought tolerance. During the summer, carpetgrass produces numerous tall, thin seed heads, which make the lawn unattractive unless mowed frequently. It also has poor cold hardiness, turning brown with the first cold spell, and is slow to green-up in the spring. The texture of carpetgrass is medium, and the is color light green. Carpetgrass has poor salt tolerance. Several insects, nematodes and diseases, especially brown patch disease, also trouble it. Carpetgrass prefers acid soils (pH: 5.0 to 5.5).
Carpetgrass is not recommended for a high-quality lawn; however, it can be used in wet, shady areas where ease of maintenance is more important than quality. It is often sold as a blend with centipedegrass to serve as a nurse or cover crop. Unfortunately, after establishment, carpetgrass develops a coarser texture, lighter green color and thinner stand than centipedegrass, and its “crabgrass-like” seed head gives it the illusion of being weedy. Currently, selective herbicides are unavailable to remove carpetgrass from centipedegrass. Therefore, it is not recommended to plant these grasses together unless their coexistence is acceptable.
Chase is an improved cultivar.
Excerpted from Southern Lawns: Best Management Practices for the Selection, Establishment and Maintenance of Southern Lawngrasses, EC 707, 2003