That is good general advice, Jeremiah, and particularly true in the summer. A lawn mowed too short will often have a shallow root system with little total root mass. The impact of shallow, weak root systems is most apparent during summer stress periods. When soil moisture becomes limiting, closely mowed lawns usually exhibit stress first and the loss of turfgrass plants is more likely. Higher mowing heights during the summer period will keep soil temperatures cooler, preserve soil moisture and help maintain turfgrass quality.