I get faced with this question quite often from some of my customers, but mostly from people I know or talk to in general. "My lawn looks so good and green from about May to mid July then I start to get dry areas and brown areas scattered throughout my yard. I water on a regular schedule for 25 min per zone and some times longer. I had the sprinkler guy come out and adjust my heads and he says everything is getting covered. What should I do?" The facts that I typically gather are; 9x out of 10 its Sandy soil, only happens during the dog days of summer, happens on flat and elevated areas, they fert on a routine basis usually with something that consists of 20-30(N), 0(P), 10-20(K) ie. 29-0-19 for the summer app. I usually tell them to make sure they are getting enough water down in those areas and check it with a rain gage. Change watering schedule to 2 start times just during the summer heat, or advise them to water more (deeper), and less frequent before the hot months arrive. Change mowing height. Advise on gypsum or lime on those areas to lower Ph. Over-seed and top dress areas w/Blk dirt. With my customers when I applied some of these techniques who have a similar cenerio it usually works, but not all of the time. What else could I suggest, and what else could be done?