St. Augustine grass (Stenotaphrum secundatum) grows well throughout the state of Florida. It is the most widely grown lawn grass in the state, according to the University of Florida. The grass produces a deep, dark green lawn that can tolerate salt, shade and sun. The grass must receive regular, ample watering to maintain its green color. The winter months cause the grass to lose its vibrant shade of green. It suffers from a variety of pests and problems, which often makes it a difficult grass to care for.
The chinch bug (Blissus insularis) poses a problem for St. Augustine grass. Both young nymphs and adults readily feed on the lawn. Large areas of the grass are consumed and killed when the bugs suck the juices of the plant and consume the stems. These dead areas pose an ideal location for weeds to invade a well-manicured lawn. The chinch bug is highly resistant to most pesticides, which makes control difficult. Control of adults and nymphs can often be obtained through insecticides but they have very little effect on the eggs, so ongoing applications are necessary. It is believed that overuse of nitrogen fertilizers may contribute to the chinch bug problem, according to the University of Florida.
White grubs pose a serious problem for St. Augustine grass. The grubs are actually the simple larvae of the June bug and the May beetle. The grubs grow below the soil surface in the summer and fall. As the grubs grow, they will actively feed on the roots of St. Augustine grass. The damage to the grass does not appear until the following spring when large, round areas of lawn will appear brown and dead from the root system being destroyed by the grub and unable to produce enough nutrients to sustain the grass through the winter months. Insecticidal drenches offer moderate control of the white grub population.
Ground pearls (Margarodes spp) are tiny scale insects that enjoy feeding on the roots of St. Augustine grass. The insects attach their sucking mouth to the root of the grass and then begin to secrete a waxy substance that encases the insect in a hard covering for protection. This waxy substance gives the insect its name of "ground pearl." The insects avoid insecticide usage with their "armor covering." The best way to combat ground pearls is to maintain a regular irrigation and fertilization schedule for the St. Augustine lawn grass to keep it healthy.
Brown Patch Disease
Brown patch disease (Rhizoctonia solani) is a fungal infection. The disease causes the grass to turn yellow and brown in small patches. The grass outside the brown grass will appear black and wilted, according to the University of Florida. The base and stem of infected St. Augustine grass will appear black. The fungus thrives when the temperature is below 80 degrees F. Too much nitrogen fertilizer also helps the fungus flourish. Water reduction to a once a week watering is the ideal way to combat the fungus. A fungus preventative can be applied prior to the infection. Propiconazole and thiophanate fungicides are recommended as a preventative by the University of Florida.