It is important to adjust your mowing height in the fall as the temperatures begin to drop. You should aim for a cutting height of 2.5-3 inches (6-7 cm) as this will provide enough leaf surface area for photosynthesis, protect against frost injury, and help retain moisture during winter months. Additionally, leaving grass a little longer helps insulate roots from cold weather extremes and can encourage more drought tolerance in the spring. Finally, allowing the lawn to remain slightly taller reduces wear on turfgrass caused by frequent mowings throughout the season.