St. Augustine Grass Lawns
St. Augustine is a course, perennial, warm season grass that spreads by stolons (aboveground) but not rhizomes (underground.) It’s widely used along the Gulf Coast in the U.S., from the Carolinas to Florida, and west to Texas and southern California. It’s also found in Mexico, South America, the Caribbean, South Africa, western Africa and even Australia. St. Augustine grows in a variety of soils and will tolerate some shade, lots of heat, salt, and some drought. It doesn’t like to be waterlogged, and it can’t tolerate very cold temperatures.
St. Augustine grass grows best in USDA hardiness zones 8-10. Although we do see St. Augustine in some of the lawns we service, our service areas (central & northwest AR, Memphis, TN, Tulsa, OK, Birmingham & Huntsville, AL, Augusta, GA, and N. Augusta, SC) cover zones 6b-8b. Find your hardiness zone by zip code.
St. Augustine will turn brown and dormant in the winter, unless it’s in coastal or tropical areas where it’s warmer, in which case it will remain green year round. St. Augustine cannot withstand cold winter temperatures which is why it does best in southern areas. However, it will retain its color longer at lower temperatures than bermudagrass, down to 10 degrees, and it does fine in very hot weather.
St. Augustine may go into premature dormancy without water. Although it loves the heat, it will turn brown if it doesn’t get adequate water.
Be careful what you put on your St. Augustine. Many “weed ’n feed” products designed for bermudagrass or fescue contain an ingredient called 2, 4-D which will damage or kill St. Augustine. If you’re a DIY with a St. Augustine lawn, read the labels carefully before you buy!
St. Augustine is typically established with sod, sprigs or plugs. Seeding is not recommended, and seed is not widely available.
A variety of St. Augustine cultivars have been developed, like Raleigh, Floratam, Floratine, Seville, Palmetto, and Bitter Blue, and each has its own strengths and weaknesses. Some say the common Texas St. Augustine is probably the most cold-tolerant of these, and others believe Palmetto is the most cold-tolerant and shade tolerant of all of them. Floratam is said to exhibit superior resistance to the SAD virus (St. Augustine decline) and chinch bugs as well as being the most drought tolerant. Raleigh is susceptible to chinch bugs and brown patch disease, but not enough research has been conducted to establish its drought-hardiness or cold-hardiness.
St. Augustine will tolerate some moderate shade better than bermudagrass, but cannot thrive in heavy shade – it can take about 40% shade, more than any other warm season grass.
St. Augustine can produce a nice lawn with proper mowing in warm, moist climates, but is not quite as tolerant of high traffic as bermuda. With more maintenance, St. Augustine can provide a very desirable lawn with a thick, dark green, lush turf capable of crowding out weeds. The mowing height for St. Augustine is 2.5 to 4 inches. Shady lawns should be mowed at 3” to 4”. Generally, the lower you mow it, the more frequently you will have to mow, but the result will be a higher quality turf.
St. Augustine grass should NOT be scalped in the spring like other warm season grasses. St. Augustine spreads by above-ground stolons, and scalping can damage the lawn.
St. Augustine is native to the Gulf of Mexico region and the oldest records show it has always been there and also on the Atlantic coast of Africa. People moved it inland for use in pastures, but not very far, since it requires the moist coastal climate.
St. Augustine will grow in a wide range of soil types, but it must have good drainage and good fertilization.
St. Augustine can be susceptible to insects and diseases and winterkill. Chinch bugs and white grubs are the biggest problem for St. Augustine, but webworms, armyworms and nematodes may invade St. Augustine also. Diseases like brown patch, grey leaf spot, dollar spot, and SAD (St. Augustine decline) can also be a problem. Different varieties are more susceptible to different things. The Texas common variety is hardier than most, but has a lot of problems with SAD, a virus somewhat like Spring Dead Spot – it causes yellowed, mottled, discolored patches in the lawn, or areas that simply do not green up in the spring. Like Spring Dead Spot, there is no control for SAD – it’s best to plant a SAD-resistant variety like Floratam, Raleigh, or Seville.
St. Augustine can develop a very heavy thatch layer. Thatch can be a problem because it may harbor insects and diseases. A St. Augustine lawn with more than ¾” of thatch should be dethatched. If you feel your lawn needs dethatched, we urge you to contact your local county extension service for recommendations, as opinions seem to vary on this subject. Two points seem to be consistent. 1 – Dethatching should be done with a dethatching machine with vertical blades no closer than 3” apart. Most commercial dethatching machines at rental stores have blades ½” apart. 2 – Dethatching or scalping will damage your lawn, so you cannot do it unless your lawn is healthy and actively growing. After dethatching or scalping, you can expect some recovery time in which you will have to pamper your lawn with water and fertilizer.
Good things about St. Augustine grass:
- Good choice for southern United States and coastal areas
- Thrives in heat
- Can take more shade than other warm season grasses
- Can be beautiful with good maintenance in warm climates
Bad things about St. Augustine grass:
- Has coarser leaves than some other warm season grasses
- Will turn brown without proper irrigation or in cold temperatures
- Cannot withstand very cold temps, susceptible to winterkill in cooler areas
- Won’t stand up to high traffic as well as bermudagrass
- Susceptible to SAD virus and grey leaf spot disease (although some varieties are more resistant than others)
- Susceptible to chinch bugs, white grubs and other pests
- Heavy thatch producer
St. Augustine trivia
St. Augustine is also known as Charleston grass in South Carolina.
The Floratam variety of St. Augustine is so named because it was developed in a joint effort by the University of Florida and Texas A&M.
St. Augustine Grass Lawn Care Calendar – from the University of Arkansas
St. Augustine Grass – info from Texas A & M
St. Augustine for Florida Lawns from the University of Florida includes information on the many different cultivars. (This one may take a minute to load.)