Things You'll Need
Weed killer containing 2,4-D
St. Augustine grass, or Stenotaphrum secundatum, is native to the tropical regions of North and South America. In recent years, it has become one of the standard species for lawns all across the continental United States, South America, Hawaii and South Africa. While most people find this type of grass easy to maintain, it can be a pain if its growth is interfering with another type of grass you have planted.
Locate the areas of St. Augustine grass. Scour your lawn to make sure you get every last bit. Put a piece of string around the areas so you'll be sure to know where they are located.
Purchase a weed killing product containing 2,4-D, making sure the 2,4-D is the main ingredient.
Spray herbicide on the St. Augustine grass to kill it. The grass around the area may become discolored but will recover quickly.
Build a barrier between your yard and the neighbor's yard if the St. Augustine grass is encroaching from an adjoining yard. Since St. Augustine spreads above the ground, build a concrete or plastic barrier about 4 to 5 inches high between the yards to ensure the grasses stay on their proper sides.
Wait until your grass becomes dormant, if you have a type of grass that ceases to grow in the winter.
Remember that herbicide kills all plants, so you'll want to be careful unless you plan to replant everything around that area.