You don’t want to mow your lawn too low. Generally, you should not remove more than one-third of the glass blade height. If you cut too low, you expose the lawn’s canopy to the sun and heat, which can increase weed growth. Taller grass retains more water, produces more chlorophyll, and provides shade for the soil.
Use the three-inch (7.62 cm) setting on your mower. You can change the setting by moving the adjustable handle near the front wheel. The higher you cut, the more the grass roots will extend into the soil. The roots of a one-inch-high blade of grass will only extend three inches into the soil, while those of a three-inch-high blade will go up to nine inches deep. Deep roots translate into a healthier and more resilient lawn.
For the final mowing of the season, it is recommended that you cut the grass to a height of two inches in preparation for the colder weather.