I am an grass cutter only that does NOT apply fertilizer. I started cutting a neighbor's yard who had a stroke. Last year it looked really nice, but over the course of this summer, it developed brown spots, kind of like camoflage. I think it is fine fescue. His fertilizing company said too much water (he has an in-ground system), then they said a fungus. I'm not trying to horn in on anyone's business, but this is an older, sickly guy who is pretty upset over the decline of the appearance of his lawn. Any suggestions?