Ronald Strahan, Koske, Thomas J.
St. Augustinegrass (Stenotaphrum secundatum) is one of our two most popular lawn grasses in Louisiana. It is widely adapted to the humid Deep South. It is so popular because its stoloniferous growth is thick and tolerates a wide range of soil and environmental conditions as well as retaining some winter color better than any other warm-season grass.
Selections of St. Augustine come in medium-dark green to blue-green and are all considered coarse-leaved. Most St. Augustine cultivars tolerate drought, shade and salinity well. They tolerate a wide range of soil types but prefer a soil pH of 6 to 7 in a medium-heavy soil type. Growth is strong during warm-to-hot weather if moisture is ample and fertility is at least medium. This grass will also tolerate some compaction in heavier soils and does fair to well with traffic wear.
Some disadvantages of this grass cause people to choose better-adapted or more appealing turfgrasses. St. Augustine has a coarse leaf texture and requires a taller cut (2.5 to 3.5 inch). It is prone to thatch buildup and a spongy turf. Above hardiness zone 8B (Alexandria), it is likely to experience more freeze damage. This keeps a reasonable use limit ranging from Dallas to central Mississippi, over to central North Carolina and southward. It really thrives along the Gulf South-I 10 corridor. It is planted as pieces (plugs, sprigs) or sod.
Another big issue with this grass type is that it suffers from several pest problems. Several diseases can ruin an attractive lawn, and chinch bugs find it very attractive. Often its vigorous growth will repair damaged areas when growing conditions are good and there is at least a moderate level of fertility.
A number of weed problems may become apparent over time, but the coarse texture masks the problems for a while. That is a good thing because this grass is sensitive to many common herbicides and has few products labeled for use on it.
Seed heads can be seen in mid- to late summer. They are mostly inconspicuous, forming a short, thick spike. If plentiful, they may give the turf sward an off color; however, regular mowing minimizes this seed head problem.
Quality St. Augustinegrass is always established vegetatively through 4-inch plugs, sod strips or solid sodding. The years of breeding and selection have produced named vegetative cultivars that have the better qualities that we prefer and require. Popular varieties include RALEIGH and PALMETTO. SEVILLE and DELMAR are less common semi dwarfs; however, there are several others like MERCEDES.
The Gulf South and Deep South have long cherished this grass, and it still remains very popular today.