Warm-season St. Augustine grass has a lot to recommend it. The grass grows fast and creates a dense lawn that resists weeds; it tolerates salt air and salt in the soil; it's heat-resistant; and it grows in shade. To enjoy these qualities, you need to keep a few things in mind when caring for St. Augustine grass. It likes neither drought nor too much water, over-fertilizing makes it vulnerable, and it isn't suitable for high traffic. Knowing these factors and using common sense will go a long way toward maintaining St. Augustine grass properly.
Look between grass blades in the spring for thatch, which is organic matter that doesn't break down fully into soil.
Rake the grass vigorously if the thatch has accumulated more than a half-inch. Don't de-thatch if the grass is still dormant. Don't de-thatch if the soil isn't dry.
Mow regularly to avoid cutting off too much of the blade at one time. Mowing frequency will depend on how the grass is growing. In spring, mow low, then increase the height gradually to 2 or 3 inches as summer progresses.
Water St. Augustine grass weekly unless your area gets regular showers, using about a quarter-inch of water. Put a can with a mark drawn at one-quarter inch in sprinkler range to measure how much you've watered.
Fertilize the grass with a slow-release product up to three times during the growing season unless there is a drought.
Test the soil every two years or so to monitor pH and the soil's nutrients. Over time, fertilized soil becomes acidic. St. Augustine grass likes a pH between 6 and 7.
Apply lime to the lawn, then water it in if the pH is below 6.
Apply pesticides according to directions if chinch bugs--a threat to St. Augustine grass in hot, dry weather--invade. Chinch bugs make yellow spots before killing the grass.