It is a coastal pioneer, occurring as far down as the high tide level in Florida, and going up to premontane areas of the tropics, e.g., the foothills below Mt. Pelee in Martinique.  Some cultivars have moderate shade tolerance, which makes St. Augustinegrass the best choice for mature landscapes with trees.  However the main cultivar, Floratam, has poor shade tolerance.

Given adequate irrigation and regular mowing, St. Augustinegrass is the most well adapted turf for home lawns in south Florida.  Its spreading stolons tend to run over the tops of other species, including weeds.  It's rugged stolons make foot traffic difficult, although dwarf cultivars such as Seville are available.