A high-nitrogen fertilizer, such as Pennington UltraGreen Lawn Fertilizer 30-0-4, helps lawns establish vigorous roots, increase energy reserves and survive winter. Overseed thin lawns. Fall conditions are ideal for germinating cool-season grass seed. Overseeding thin lawns pays off with thick, strong, spring grass.

For warm-season grasses, the timing is late spring-early summer. For cool-season grass, it's early fall. Aerate so that grass will have at least four weeks to recover and grow before frost arrives. If possible, spread fall fertilizer on cool-season lawns shortly after aerating.

In late fall, drop your mower down and cut your lawn 1 to 2 inches shorter than you have the rest of the growing season. Continue to mow shorter until your grass stops growing in early winter, when both you and your lawn head into hibernation mode. For that final mowing, go even a little bit lower.