Organic matter that shredded leaves provide when added to your soil is packed with trace minerals that the tree draws up from deep in the earth. Leaves are one of the best sources for improving your soil whether for gardens or flower beds and fall is the best time to add them.
Chop Them Up
Shredded leaves break down much quicker than whole ones. You can use a mulching lawn mower to mow them into small pieces, or collect them and put through a leaf shredder, or use a leaf blower that also shreds leaves.
Leaves shredded into small pieces provide an increased surface area so microbes can do their work and it prevents the leaves from packing together and forming a mat that doesn’t let water and air penetrate to the soil. You can bag more shredded leaves than whole leaves.
Add to Your Gardens
Leaves can be added to bare soil in the garden or flower beds and worked in a little to help reduce the number of weed seeds that can take hold in the spring. A thick layer of leaves also provides winter protection to garlic, tender perennials and roses. Any shredded leaves left can be placed in plastic or paper bags and stored for use in the spring and through the summer.
Feed the Worms
I always keep some fall leaves to use in any new raised beds I build in the spring or to add to existing beds. The leaves encourage worm activity which aerates the soil and feeds the worms who dig small tunnels through the ground to allow air in and leave their waste to nourish my planting beds.
Store What You Don’t Use
Leaves can also be stockpiled to create compost for your gardens next spring. Every time you add food scraps to the compost pile, add a layer of dry leaves (food is the green stuff, leaves are the brown stuff). This discourages animals from invading your compost bin and provides the right mix for a hot compost pile. You can do this all winter if you save your shredded leaves.
A three-bin system works very well for composting and you can keep it going all year. One bin holds the green and brown material that is heating up so the material composts. One bin holds the shredded leaves for conveniently adding to the hot bin, and the third bin holds the finished compost. A little of the finished compost can be added along with the leaves when you add more food scraps. See https://en.wikipedia.org/wiki/Compost
So, shred those leaves, cover all your growing areas with a thick layer, use some for your compost bin, and save some for next spring.