St. Augustine grass is a warm-season turfgrass that's commonly found in lawns where winters are mild and summers are hot. Although St. Augustine grass has a limited growing region, it will thrive in warm temperatures, sunny lawns and high humidity. This grass type tends to be higher maintenance than other warm-season grasses, because it doesn't handle droughts well; isn't able to grow from seed, only sod, sprigs or plugs; is more susceptible to diseases, insects and thatch buildup; and requires frequent mowing. St. Augustine grass does create a beautiful lawn, however, with wide, deep bluish-green blades.
Water your St. Augustine grass lawn deeply once each week, wetting the soil to a depth of 4 to 6 inches, throughout the late spring, summer and early autumn. Water the lawn whenever weekly rainfall is less than 1 to 1 1/4 inches.
Mow your St. Augustine grass lawn once every five to seven days, beginning in March or when the grass turns green again in spring and stopping when the grass goes dormant in October. Maintain a grass height of 2 1/2 to 4 inches, never removing more than 1/3 of the total grass length in a single mowing.
Feed your St. Augustine grass about three weeks after it turns green again in spring, providing 1/2 pound of nitrogen per 1,000 square feet of lawn. Apply 1/2 to 1 pound of nitrogen per 1,000 square feet of lawn again in late June or early July and once again in mid-August.
Dethatch your St. Augustine grass lawn in early summer using a power rake with a 3-inch-wide blade spacing or a lawn aerator if the thatch is more than 3/4 inch. Check the thatch level in the lawn by looking at the dead grass or debris buildup on the soil and beneath the living grass blades.
Apply a pre-emergent herbicide to your St. Augustine lawn in late winter, if crabgrass or goosegrass are chronic weed problems in your lawn. Follow the application instructions on the label exactly.