Bermuda Grass and St. Augustine Grass - Pros and Cons

St. Augustine and Bermuda grasses are popular grasses that are planted in the early summer in the south. Understand the similarities and differences between St. Augustine grass and Bermuda grass so you can choose which of the two is best for your grassy area.

Temperature

St. Augustine does not tolerate cold temperatures well; temperatures below 65 degrees F in the evening can cause a St. Augustine lawn to develop fungal diseases that cause brown, rotting spots.
Bermuda grass also does not take well to cold temperatures. According to "The Lawn Bible" by David R. Mellor, Bermuda grass goes brown and dormant in temperatures below 50 to 60 degrees, to return when temperatures rise again. For this reason, Bermuda grass is a better choice for normally temperate areas that experience cold spells, since Bermuda grass turns brown but will not die off completely in moderately cold temperatures.

In the right climate and soil, St. Augustine is a densely growing carpet of slightly rough grass. Most weeds cannot grow in a carpet of healthy St. Augustine, making it a good grass choice for warm areas where lawn weeds are a problem on other types of grass. St. Augustine is most often known as the grass on the rough of a golf course.
Bermuda grass also has a strong carpet that is weed-resistant. Bermuda grass can take a lot of beating and foot traffic, so it is frequently used in playgrounds, in parks, and on athletic fields.

Shade Tolerance

St. Augustine stays healthy in the shade, making it a good choice for grass that receives shade from nearby trees. Bermuda grass will not stay green in shady areas.

St. Augustine grass grows best in the southern United States, Central America, and South America, as does Bermuda grass. The drought-tolerant properties of Bermuda grass make it a popular choice in moderately dry areas in India, Australia and Africa.

Growth

Bermuda grass is very low maintenance and grows quickly. Deep roots make Bermuda grass tolerant to drought. In dry spells, Bermuda grass goes dormant and grows back when it is wet again. In some places, Bermuda grass grows so aggressively that it is considered a weed, so Bermuda grass is not a good choice for use near flower beds, food crops or near walkways that you want to keep clear.
St. Augustine is not an aggressively invading grass, but it is high-maintenance. St. Augustine can require a lot of mowing. According to "The Lawn Bible", St. Augustine is best kept at a height of two to four inches.References:

Texas Cooperative Extension: St. Augustine Grass; Richard R. Duble
Texas Cooperative Extension: Bermuda Grass
"The Lawn Bible"; David Mellor; 2003