Lawn and Landscape Checklist - June Make sure the lawnmower blade is still sharp. Sharpen if needed. As the weather heats up you can raise the mower cutting height to 3 inches. The taller grass will shade the roots a bit and keep them cooler. Monitor for grub infestation. Treatment generally is warranted if six or more grubs are found per square foot. See article Summer care for a healthy lawn for details. Smooth out any bumps, depressions or holes in the lawn. Keep any flower heads forming on chrysanthemums trimmed off until the 4th of July to provide for sturdier plants and best blooming this autumn. Remember to change the direction you mow the lawn each time to avoid ruts.