In the last few mowings prior to the very last mow of the season, lawns should be mowed at a height of 2 1/2 inches to 3 inches. This height allows the blades to continue to make food for the plant and store nutrients prior to going dormant for the winter.
For the last cut of the lawn before winter, reduce the mowing height to between 2 and 2 1/2 inches. This is the appropriate height for your lawn in winter. Lawns at this height are less susceptible to diseases such as snow mold.
As soon as temperatures warrant in the spring, the lawn should be given the shortest mowing of the year. It can be cut as low as 1 1/2 inches to 2 inches to help remove dead blades and remove debris that settled on the lawn over the winter.