Hi Rose! Here is some very good information for you. I wish you the best!
I have St. Augustine grass too. I fertilize early spring, and late fall. Too hot where I live to fertilize in the summer.
Wait until spring when it begins to turn green, the add a Weed and Feed fertilizer that is SPECIFICALLY made for St. Augustine grass. Water as needed during drought time, but no more than any other grass. Also it grows best in well drain type of soil like with much sand. Hope this helps Rose
check with your local Agriculture Agency to get a SOIL SAMPLE performed --- more harm than good is done by using the wrong product at the wrong time -- it's better to do NOTHING than to do the 'wrong' thing!