Fallen leaves make free mulch for your garden each fall. In our town, people bag those extra leaves in clear garbage bags for once a week curbside pickup. The clear bags make the leaf bags easy to distinguish from any common curbside trash.
This is my garden, all mulched with a thick carpet of free fall leaves. Put on thickly, the mulch lasts all season until it is time to add more leaves the following fall.
You could also use extra leaves for your compost pile.