It is important to continue to mow a lawn until it stops growing. This varies by geographical location, but it is usually about the time when daily average temperatures fall below 50 degrees Fahrenheit for a week.
Keeping the lawn at a height of 3 inches is ideal. If the grass is allowed to grow past 4 inches, the blades can shade each other and reduce the photosynthesis process still taking place. Longer grass blades can also fall over, causing the grass to mat together and encourage the growth of snow mold. Mowing fall leaves into the lawn is helpful to the soil and grass.