St. Augustine grass, a dense, green to blue-green turf is widely used for lawns along the Gulf Coast. It originated in the tropics and is native to the ridges of sandy beaches, the fringes of lagoons and swamps, limestone shorelines and both fresh- and saltwater marshes. St. Augustine grass tolerates high temperatures but is not without its problems.
St. Augustine grass will not remain green under drought conditions. It needs to be irrigated during prolonged dry periods.
Poor Wear Tolerance
St. Augustine grass does not wear well. If it is used heavily or subjected to a lot of foot traffic, it will not stay green during the winter.
Subject to Scalping
If St. Augustine grass is cut too short ,the stems are exposed, and the turf can turn yellow or brown. If St. Augustine grass is not mowed properly, it may develop thatch or a thick mat. This can also cause symptoms with scalping.
Susceptible to Insects
The major problem St. Augustine grass has with insects is the chinch bug. There are no cultivars of St. Augustine grass that resist damage by it. The chinch bug feeds on the stems at the base of the leaf sheath. The grass looks like it is suffering from drought. Feeding bugs can cause it to become stunted with irregular patches of dead grass.
The fiery skipper, an insect that looks like a butterfly, may feed on the leaves of St. Augustine grass causing brown spots. Armyworms, cutworms, grubs and sod webworms may also feed on St. Augustine grass. They leave silk-like webs in the early morning, and they can kill irregular patches of lawn.
Ground pearls and subterranean scale insects can damage the roots of St. Augustine grass. They strike in the spring and summer, especially in dry weathers, causing irregular areas of dead grass.
Several types of nematodes may infest St. Augustine grass, causing poor root growth and thinning of the grass.
Susceptible to Disease
St. Augustine grass may be struck by a number of fungal diseases including brown patch, downy mildew, gray leaf spot, helminthosporium, pythium, root rot and rust. These diseases can be controlled by fungicides. St. Augustine grass decline (SAD) is a viral disease that suppresses growth of the turf; there is no chemical control, although there are cultivars of St. Augustine grass that resist SAD.
No Effective Herbicides
Healthy St. Augustine grass crowds out most weeds, but once weeds get started, it is difficult to stop them. There are no herbicides on the market that can control the spread of weeds in St. Augustine grass.