The dead leaves that fall from your trees each autumn can be a valuable resource for fertilizing or mulching your garden or yard if you shred them. There are yard machines called shredders that are designed to shred leaves and other vegetation, but they are costly. If you have a rotary lawnmower, however, you can shred the leaves quite effectively just by mowing over your yard.
A mulching mower is a rotary lawnmower with a deep deck that's fitted with a serrated blade designed to chop and shred grass and leaves into small pieces. These mowers allow users to close off the discharge chute so the blade gets several chances to chop up the leaves as they fall to the ground. But you can also use a regular side-discharge rotary mower for leaf shredding. Attaching a mulching blade to a regular mower will reduce leaf size, though it might not shred the leaves as small as a mulching mower will. Depending on the mower, some brands offer shredding attachments that include screens, which reduce leaf debris size.
Pick Dry Day
Set your mower height to 3 inches for shredding. Remove any grass-catching attachment. Don't wait for all the leaves to fall off before starting your shredding; you could choke out your mower. Do a shredding run on a dry day when you can still see some green poking through the leaves. Make sure the leaves are dry; wet leaves won't shred well and may clog up your mower.
Begin mowing along the outer edge of the lawn, working toward the middle. Then make a second pass over the lawn at a right angle to the first pass. If using a regular side-discharge mower, direct the discharge toward the lawn's middle. The shredded leaves will fall down to the lawn's root level where they will decompose quickly. When shredding leaves with the mower, be sure to wear shoes and safety glasses to protect your eyes from flying leaf debris.
Clean It Up
If leaf mowing results in a layer of shredded leaves so thick that you can't see the grass, you need to rake them up or collect them in your mower's grass-catching attachment. The shredded leaves can go into a compost pile or serve as mulch in your garden or flower beds. Rake up and bag any leaves that are diseased. Using diseased leaves in the garden or allowing them to remain on the lawn in their shredded state can transfer the disease to healthy plants.