The first thing to keep in mind when considering converting grass clippings, plant and tree leaves and other yard waste into garden mulch is to make sure none of it comes from diseased plants. This will contaminate the mulch and spread the disease around the garden. Diseased leaves, twigs, flowers or other waste must be disposed of, preferably by burning. Also, do not plant new plants in the same location where you pulled up a diseased or dead plant. Check with your cooperative extension to find out how long you have to wait. It will depend on the new plant and the type of disease.
Not only is it a good way to make sure you have an all organic mulch, it may well be the law. Many states have restrictions on putting yard waste in the trash. It takes up too much space in the landfills.
Break up fallen leaves and pine needles with a lawn mower and just let it sit. It will decompose quickly and return to the soil or pick them up with a bagging mower and use for mulch around trees and shrubs.
Use the twigs and leaves from pruning shrubs, dead plants and even weeds by cutting them into pieces from 6 to 2 inches long and just spread around shrubs and trees. Another choice is to shred with the mower or put them through a chipper or shredder. This looks more like mulch while the first option has a more natural look. Larger limbs and thick branches have to be put in the shredder or chopper, unless you want to use them for firewood.
You also have the option of adding the material to the compost bin. Grass clippings do not do well as a mulch, so just leave them fall where they may and let them become fertilizer or add them to the compost bin as well.
There is a second advantage to using your own debris as mulch besides helping the environment. Think of the money you will save. Yes, it requires a bit of work, but not much more than you would be doing anyway in the normal routine of gardening. If you end up with too much mulch for your own use, offer the excess to a neighbor. Maybe you will be the inspiration for getting the neighborhood to become eco conscious as well.
University of Florida