One of my neighbors that I mow for hasn't needed her whole back yard cut in a year and a half, I kid you not. She has 4 kids and so do the people between my house and hers, between them and a few other neighbors, there's almost always 12 kids playing kickball in my client's back yard. I can not figure out why the grass won't grow, she has a sprinkler system and ChemLawn, but it won't grow. When I mow I only make 2 passes around the perimeter of the yard and use the weedeater (I know someone's going to correct me and point out that weed eater is a brand, I don't care, that's what I say and I'm sticking to it) on a few spots of crabgrass. I am out of ideas, anyone have any suggestions?