Gardening in Gwinnett: St. Augustine turf not popular but possible in this area

Of all the turf grass types and varieties, St. Augustine is one of the most beautiful and also tends to have better shade tolerance. St. Augustine is the turf of choice in the middle and southern part of Georgia and is grown throughout Florida. It has large flat stems and broad coarse leaves with a blue-green cover, and forms a dense, thick turf and spreads by long, above-ground runners. The turf is not seeded, but is installed by using vegetative parts, such as sod, sprigs and plugs. When planted during the growing season and given the right cultural conditions, the turf quickly establishes itself. Some varieties are more drought tolerant than others, but generally the turf will need some supplemental water during drought periods or it will brown out.

In our area, St. Augustine is not the best turf of choice because it has a low tolerance to cold and a severe winter freeze has the potential to seriously damage the turf. However, it can be grown in our area, and I have seen many lawns where it is growing successfully. Despite being more sensitive to cold, it usually stays green longer in the fall and sometimes it can still be green in the middle of winter in protected areas or under fallen tree leaves.

To establish and maintain a good stand of St. Augustine turf, certain cultural practices are necessary. It requires proper fertilization. Fertilize when growth begins in spring and again in early summer with an all-purpose turf fertilizer. The soil should be tested before fertilization is done. Sometimes a fertilizer with an iron supplement is needed to provide optimal growth. The turf prefers a lower pH soil. Most soils in our area are acidic.

Most St. Augustine varieties prefer being mowed at a height of 3.5 to 4 inches. Mowing it too low can increase the susceptibility to drying out, insect and disease problems, and the turf will become easier to scalp. The semi-dwarf varieties can be maintained at a lower height of 2 to 2.5 inches. Never remove more than one-third of the blade.

St. Augustine is highly susceptible to an insect pest, the chinch bug. The insect thrives in hot, dry conditions, and can be controlled by insecticides, but frequent applications need to be made throughout the growing season. If you suspect chinch bugs, get a tin can and cut both ends off. Push it into the soil in the suspect area, and then fill it with water. The chinch bugs will float to the surface. Proper cultural management techniques to control chinch bugs include regular thatch reduction, proper watering and not over-fertilizing.

There are several varieties of St. Augustine for our area. Floratam and Floralawn is resistant to chinch bugs and a viral disease, St. Augustine Decline. Bitterblue is more cold tolerant but more vulnerable to chinch bugs. Raleigh is one of the more cold tolerant varieties available. Seville is a semi-dwarf variety with dark green, fine texture, but is not as cold tolerant as some of the others.

Growing St. Augustine in our area can be a challenge, but if the proper growing conditions are provided, you can have an attractive lawn of this turf grass. Just be conscious of the problems and drawbacks of St. Augustine when deciding what type of turf you want for your lawn. For questions regarding St. Augustine lawns, call the Gwinnett County Extension office.

Timothy Daly is an agricultural and natural resource agent with Gwinnett County Extension. He can be contacted at 678-377-4010 or timothy.daly@gwinnettcounty.com.