St. Augustine grass (which is known also as St. Augustinegrass) graces southern lawns--especially coastal lawns--as a warm season grass, growing quickly into a dense lawn that resists weeds. Some of St. Augustine's especially commendable qualities include its ability to grow in shady areas, standing up under heat and tolerating some salt. Maintaining St. Augustine means paying attention to heat, temperature and feeding, then adapting accordingly. You would not, for instance, fertilize for growth during a drought, putting extra stress on the grass. Use common sense.
Examine the lawn for thatch by looking between grass leaf blades for partially decayed organic matter that may be building up rather than breaking down fully into soil.
De-thatch with the rake--that is, comb the grass vigorously--if thatch has gotten thicker than a half inch. Only de-thatch while the grass is growing and wait until the soil is dry.
Mow the grass low in spring, gradually increasing height to two or three inches as the weather gets hotter. Try not to remove more than a third of the blade all at once. Mow regularly.
Water once per week, using about of one-quarter inch of water. A can marked with a one-quarter inch line placed within sprinkler range will help you monitor how deeply you are watering.
Use a slow release fertilizer up to three times during the growing season, in early spring, early summer and late summer. Do not fertilize during periods of drought.
Test a soil sample every couple years to make sure the soil pH has not become too acid over time. If the pH has dropped below 6 (St. Augustine likes a pH between 6 and 7), apply lime and water it in.
Use pesticides, if necessary, to combat chinch bugs, a common St. Augustine problem in hot, dry conditions. The bugs cause yellow spots before killing the grass.