Hello, I'm new to the this forum and I need some help with my St. Augustine. I live in north Texas and I've been in my current house for 7 years. I've always had awesome thick St. Augustine with very little maintenance. I would water appropriately and didn't even fertilize yearly. For some reason I decided to put down a pre-emergent in the Fall. I don't recall which one it was but I do recall making sure I got one that was safe for St. Augustine. Now here we are in the spring and I have the worst looking lawn in the neighborhood. I have huge spreading patches of completely dead grass, blades and stolons dead. If I rake off the thatch, it's bare top soil. The areas where there is surviving grass don't all look super healthy either, lots of yellow/lime green blades mixed into the normal healthy green blades.
So obviously there are fungi and bugs that could be causing this but is it possible that I maybe put down a "not safe for St Augustine" pre-emergent? And if so, is there anything I can do about it?