St. Augustine Grass – Acidic Soil

Q: I have had St. Augustine grass for many years. Someone once told me to never apply lime to it. However, I see on your website that in some instances it is advisable. Can you confirm?

A: Lawn grasses, including St. Augustine, prefer to grow in soil that is slightly acid, in the 6.0 to 6.5 pH range. Even centipedegrass, which tolerates acid soil better than most grasses, seems to do better in the 6.0 region. But how do you determine what your soil pH is and how much lime is needed? You can buy small test kits that measure pH but they are not very accurate. The results could be off by one or more pH points and you wouldn’t realize it. The most accurate method is to submit a sample of your soil to a local University of Georgia Extension office (404-897-6261) and have them send it to a state lab. The process only costs a few dollars and you’ll receive a test report specifying whether you need to apply lime and the amount of fertilizer your St. Augustinegrass lawn needs.