Rene Castillo · Gardenality Seed · Zone 8A · 10° to 15° F
I mentioned I was in San Antonio Tx. You posted and answer for Zone 8A. I am in zone 8B. Does that matter? Is the answer the same for both these regions since they are so closed together?

Gardenality.com · Gardenality Genius · Zone 8A · 10° to 15° F
Rener - Might warm up just a little learlier in 8b than in 8a but the same thing applies: You'll want to fertilize St Augustine grass in mid to late spring; after it has greened up and all chances of frost have passed. Some years it warms up earlier and sometimes later so watch local forecasts closely. Typically, for St Augustine grass, if you wait until the end of April or first of May all chances of frost have passed. Using a slow-release fertilizer is helpful as all or part of the nitrogen (first number in fertilizer) will release slowly over time instead of releasing all at once causing accelerated growth that might make the grass grow fast but weaken plants over time. Let us know if you need more details. We're at your service. - Brent