For The Answer
By Dr. Calvin Finch
Choosing a turfgrass is not easy in San Antonio, none of the varieties are overwhelmingly better than the other. A lawn can be attractive and a great place for your pets and children to play but if you are intent on keeping it green all summer, it requires lots of water and work. Reduce the lawn area as much as possible with hardscape (preferably pervious), groundcover, and perennials.
St. Augustine is the most popular grass. It is attractive with wide kelly-green blades. St. Augustine is easy to mow and has the best shade tolerance. Sod is relatively inexpensive and easy to obtain. In San Antonio it requires heavy irrigation and is stressed to the point that it requires attention for insects, diseases, and iron chlorosis. St. Augustine does not have very good traffic tolerance. If it turns brown in a drought, it is dead. To keep it green requires about 0.75 inches of water per week.
Bermuda grass requires full sun. Mowed low, at 1.5 inches or less, a Bermuda lawn can look like a golf course. It is the grass used for golf courses and athletic fields in our area. Bermuda has the most traffic tolerance of the lawn grasses available, and will go dormant if water is not available. When the rains start again, it greens up quickly. Bermuda is relatively insect and disease free but is not as thick as St. Augustine, so can support weeds, especially in the winter.
Zoysia grass has some of the best characteristics of both St. Augustine and Bermuda grass. It has shade tolerance (not as much as St. Augustine) and forms a thick weed free sod. Zoysia has good traffic tolerance, is pest resistant, and can go dormant in a drought. Zoysia is the most difficult grass to mow. Emerald, a fine blade beautiful selection, has a texture like steel wool. It mows best with a reel mower. Jamur and El Toro are two good selections of zoysia that are easier to care for. Although zoysia grass has drought tolerance and can go dormant, to stay green it requires the same amount of water as St. Augustine.
Buffalo grass is the only native turf on the permanent lawn grass list. It requires only about 3/8 inch of water every week to stay green and, thus, is the least water demanding grass. Overwatering will kill buffalo grass. Plant buffalo grass in full sun on heavy soils. It is insect and disease free. The main problem of buffalo grass is weeds.
Select the lawn grass that best suites the availability of light in your yard, your aesthetic preferences, your interest in lawn work, and your tolerance for water bills. Six inches of soil is best for a good lawn. If you have less, add some, or use groundcovers instead.