It’s he-re! Temperatures have dropped, frost is in the air (and has already hit some gardens), leaves are changing color: there is no denying fall is happening right now. Soon those leaves will be dropping off the trees… and as a good citizen of planet Earth, you will necessarily be recycling the fallen leaves.
Leaves are often referred to as “gardener’s gold”. They are so rich in organic matter and minerals that they can easily replace expensive (and polluting) fertilizers. You can add them to your compost (or set a few bags of them aside for next year’s compost pile), you can apply them as mulch to your flower and vegetable beds (or you can mix them into an existing mulch), you can simply toss them into a wooded area, etc. What you don’t want to do is to just throw them away.
But if you want your leaves to decompose well, you’ll need to shred them first. Okay, this is less of an issue for small leaves (leaves of black locust, crabapple, birch, etc.), but large ones (leaves of Norway maple, red oak, etc.) cause problems if they’re left intact. They tend to clump together to form an impenetrable barrier, for one thing. Plus, leaves that are left entire tend to blow around and annoy neighbors who might not be as eco-friendly as you are. Shredded leaves, by some miracle of physics, do not clump together, nor do they blow around (apply them, water once to settle them, and you’ll see what I mean). Oak leaves cause their own special problem: they are notoriously slow to decompose if you leave them as is. Chop them into tiny pieces and they change completely, decomposing in a matter of months.
The easiest way to shred the leaves is to simply spread them on the grass (if they are not there already) and mow them. Yes, with your lawn mower. The mower will shred them into tiny little pieces, just the right size for the compost bin and for mulch!
And yes, you can use diseased fall leaves in the compost and as a mulch, in spite of where some municipalities claim. Read here for more information on that subject.