Photo found on Flickr, courtesy of dno1967.
St. Augustine grass produces a dense, blue-green turf that grows well in warm and humid climates. It’s adaptable to a variety of soils and tolerates salt and high temperatures. Some varieties can even grow in shade. It’s easy to establish St. Augustine grass lawns from sod, sprigs, or plugs.
Like most turf grasses, St. Augustine grass has disadvantages. It does not stay green during droughts and in cool winter months, and does not tolerate foot traffic. It is susceptible to grubs and chinch bugs, as well as various fungal diseases. Many people do not like the very coarse texture of St. Augustine grass.
St. Augustine Cultivars
Despite its drawbacks, St. Augustine grass is a popular choice in southern and Gulf Coast states as well as California and Hawaii. Various cultivars offer options in appearance, growth rates, and disease resistance.
Amerishade is a slow-growing, shade tolerant, dwarf cultivar.
Its popularity stems from its mowing frequency, which is less than most other cultivars. It is, however, very susceptible to disease and is slow to recover from setbacks from disease or winterkill. It also produces heavy thatch.
Delmar is another dwarf cultivar. It can grow in sun or shade, and tolerates the cold better than Amerishade. Like other dwarf cultivars, it tends toward thatch buildup.
Floratine and Bitterblue are very similar, hard to distinguish from one another. Both have finer texture and shorter blades that allow for closer mowing than other standard cultivars. They tolerate light shade, but are susceptible to chinch bugs.
Floratam is the most commonly used turf grass in Florida, despite its susceptibility to fungal diseases and its poor cold and shade tolerance. It does have resistance to chinch bugs. Seville is similar to Floratam, but with a finer texture.
Mowing St. Augustine
Standard cultivars should be mowed at 3 ½ to 4 inches, semi-dwarfs to 2 ½ to 3 inches, and dwarfs to 1 ½ to 2 inches. Each mowing should remove no more than 1/3 of the blade. Too-frequent mowing leads to thatch buildup, lower stress tolerance, and increased susceptibility to diseases.
Fertilizing St. Augustine
Annual soil tests provide guidance on the fertilizer needed for optimal growth. Homeowners can grow St. Augustine grass with low levels of fertilizer or high levels, depending on their desired outcomes and the time they have available for lawn care.
High fertility requires more frequent mowing and causes more thatch buildup. Soil pH between 5 and 7.5 is recommended.
Watering St. Augustine
Deep, infrequent watering of established lawns is preferable to more frequent, shallower watering. Deep watering helps St. Augustine grass develop deeper root systems and greater resistance to pests and other stressors.
Like overfeeding and improper mowing, overwatering leads to excessive buildup of thatch.
Want to Learn More About St. Augustine Grass?
Because St. Augustine grass is a popular choice for tropical and subtropical gardens, the Texas Cooperative Extension, the University of Hawaii Cooperative Extension, and the University of Florida Extension have helpful tips for successful lawns.
Texas A&M and St. Augustine Grass.
The University of Hawaii has a great .pdf over St. Augustine grass.
If you’re in Florida, be sure to see St. Augustine grass for Florida Lawns.