What is the best kind of fertilizer to use on my St. Augustinegrass?
We first recommend that you conduct a pH and fertility test on several different sites in your lawn. If the pH is below 6.5, then you need to add dolomite, which is calcium and magnesium. The ideal pH for St. Augustinegrass is 6.5. Every 5 pounds of dolomite applied per 100 square feet will raise the pH 1 point; therefore if your pH is 5.5 you will need to add 5 pounds dolomite per 100 square feet to raise the pH to 6.5. The Polk County Master Gardeners conduct soil pH tests every Thursday morning at the Extension Office for a $3.00 fee. To determine fertility, i.e. the amount of calcium, phosphorous, magnesium and potassium, the sample will have to be sent to the University of Florida soil’s lab. They will test for pH and fertility for $7.00. After you determine the pH and fertility, then you can shop for a fertilizer. Select a product which has the same percentage of nitrogen and potassium and with low or no phosphorous such as a 15-5-15 (15% nitrogen, 5% phosphorous and 15% potassiu
