The additional leaf area during summer shades and cools the crowns of the turfgrass plants. Extremely high temperatures at crown level can kill turfgrass. Raising the mowing height during the summer months also discourages turf diseases, such as summer patch. When mowing the lawn never remove more than one-third of the total leaf area at any one time. Removing more than one-third of the leaf area weakens the turfgrass and reduces its capacity to withstand additional environmental stresses.
Weakened turf is also more likely to be invaded by weeds.
If possible, mow in the cool of the morning or evening. Mowing during high temperatures of midday places additional stress on the turf. Also make sure the mower blade is sharp. Dull blades tear and bruise the leaf tips. Gardeners have two basic options on lawn care when confronted with hot, dry weather.