The coming of fall doesn’t signal a change in deck height for your mower. Not yet anyway. There’s still plenty of mowing left until your lawn goes dormant.
Hopefully, you’ve been mowing with the deck height at three to four inches all summer. If so, keep it at that height until the last mowing. If you’ve been mowing any lower, raise the deck up until your last mowing. For the last mowing, lower the deck to two inches.
Mowing high encourages stronger, thicker grass. Higher grass is healthier, and the longer blades of grass are able to make more food through photosynthesis. More food in the roots results in stronger roots, and thicker roots discourage weeds. Another advantage to mowing high is that you may be able mow less often. It’s like your hair; people with long hair can go longer between cuts than those with short hair. Grass blades and hair follicles grow at different rates, and the longer ones are more noticeable when the rest is short.
Long grass holds more moisture, creating an ideal environment for the fungal diseases that lawns are susceptible to in our area. That’s the reason for the last mowing being short. To know when to lower the mower, watch the weather forecasts. When the first hard frost is predicted, that’s the time to lower the mower. The mowing after the frost is the time to mow short. If that frost doesn’t drive the grass into dormancy, keep mowing low until the grass goes dormant.
Save some time and energy by combining two tasks into one – mowing and leaf mulching. Unless you have mountains of leaves on the grass surface, you can use the mulching feature on the mower to chop leaves up finely and let them fall on to the lawn. There, they’ll decompose over the winter and fertilize the lawn. If more leaves fall, there’s no reason why you can’t run the mulching mower over the lawn again, unless it has been unusually rainy, in which case you’ll have to rake or blow.
Whatever you do, though, don’t let the leaves stay on the lawn. Like long grass, leaves will retain the water from melting snow and provide the perfect climate for fungal diseases to infect your valuable lawn.,
A little preventive maintenance in the fall can go a long way toward assuring a lush, green lawn in the spring.