Mow your St. Augustine between two to four inches tall.
Apply pre-emergent herbicide. This will cut down on summer weeds.
If you have had insect problem in the past, treat with broad-spectrum insecticide. If you use a granular variety, water the lawn immediately after application to help soil absorption. Make sure it has control for chinch bugs.
Don’t overwater. In the active growing season, St. Augustine needs about one inch of water a week from natural rainfall or irrigation. Too much water can cause fungus.
Apply fungicide if needed. If you have had a fungus or disease in your St. Augustine in the past or have quite a bit of shade in the yard, apply a systemic fungicide to prevent future outbreaks.
When mowing, never remove more than 1/3 of the leaf blade at a time. If you need to cut more than 1/3, consider multiple cuts over three to five days.
Do not overwater the grass. St. Augustine only needs about one inch of water weekly. Water for longer periods of time, less frequently, and in the early morning hours. Take rainfall into consideration.