I have centipede grass, about 5 years old. The whole lawn looks very good except when it doesn't rain because my dirt is very sandy. I'm putting in irrigation for that. But I have 2 spots that the stolons are growing about 2 inches above the ground. They also have a good deal of thatch between the grass and the ground. One of these spots is on some clay that I had left over when I built my driveway. But both of these places start wilting first and get to looking real bad. I can walk across these spots and it feels like I'm walking on a cushion. Since I noticed this I have lowered my cutting height to about 1.5". So I would like some opinions as to the best method of getting this grass back down to where it sopposed to be without harrowing up the spot and starting over!