What is mulch and what use is it in the garden? Mulch is a protective barrier between your soil and the elements that helps it retain moisture in the spring, fall and summer and to retain heat in the winter.
Several materials can be mulch. The idea of mulching is to put some type of material on top of the bare soil around your plants to help that soil retain moisture. So, at this point, you've taken all this grass up, you've mixed all this stuff into your soil, and now the top of that soil is exposed to wind and to sun. One thing people don't realize: wind can dry soil out just as fast as, if not faster than sun can. If you put something on top of that soil so that it's not exposed to those elements, it will retain moisture longer. And particularly when you start getting into the summer and high temperatures, that is a great benefit.
Nowadays, most mulch is what's called hardwood mulch, which is yard and tree trimmings that are ground up into a relatively fine material that you spread on top of the soil.
You can also mulch with stones, decomposed granite or any stone type of material. I have some very large beds in my backyard that would cost me hundreds of dollars to try to mulch, so I actually use live oak leaves. They decompose really slowly compared to a lot of other leaves and I have access to all the live oak leaves I could possibly ever need! (Live oak trees are abundant in most parts of Texas, and shed copious amounts of leaves in the springtime).
