The fall foliage show is back by popular demand (and because we cannot stop it anyway). Those reds, yellows, and oranges now have begun to subside, and soon enough a night of really below freezing temperatures will bring that to a close. Then, all those leaves will end up in the landscape.
Our recent just-below-freezing temperatures caused an immediate fall of green leaves on any tree with active growth, such as silver maple and mulberry. If you are out there in the country with natural woodlands, leaves play a part in preserving the natural habitat of native trees, shrubs and flowers. If that is the case, just let those leaves lie. They will decompose and return valuable nutrients to the soil, to be used by the soil microbes that in turn support plant growth.
Where your lawn and trees exist together, mulching the leaves with a mower lets the small pieces fall between grass blades, benefiting the soil, trees and lawn. At some point, there can be more leaves than can be mulched in, and that is the time to mow and bag them so the leaves do not smother the lawn.
Where the vegetable garden and flowerbeds are adjacent to the lawn, consider blowing the leaves in to the beds, and work them in yet this fall or leave them as a mulch layer for the soil and work them into the soil next spring. Whole leaves also can be used as mulch around the base of tender plants like roses; use the whole leaf as mulch so it does not pack down, defeating the purpose of protecting the crown of the rose plant.
Any leaves collected with the lawn mower can start a compost pile or add to one you already have. That mower bag contains the two primary compost ingredients, browns (leaves) and greens (grass clippings). As you create the compost pile, some garden soil should be sprinkled in as you go to provide the pile with the microbes that will be breaking down the organic matter into compost. Since organic matter is naturally acidic, about ½ pound of a finely ground limestone should also be added for every cubic yard of material.
Your compost recipe is almost complete. Once the composting pile has been created, the final ingredient needed is water. If the pile remains too dry, no breakdown occurs. If left too wet, an anaerobic condition and decay occur, giving you a very smelly, slimy mess to deal with. Fresh kitchen produce peelings also can be added into the compost pile year round. They provide some of the moisture that is needed during the summer and after they have frozen and thawed from the winter months, provide moisture as well. If you are lacking in the fallen leaves department, just ask the neighbors who have bags sitting out at the curb. Don't let that good organic matter get away; build a compost pile. Learn more at https://extension.illinois.edu/homecompost