I took some pictures of various spots in my yard. Anyone know what may be going on? I have fertilized over the past few years 3-4 times and stayed on top of weeds. I don't have irrigation, but have watered some and it still doesn't help a lot. I wonder if it may be grub damage. The one picture I tried to dig through the dead patch and couldn't fine any sign of life under it. Any ideas of what to try?