Use weed free salt hay to avoid adding weed seeds to the garden. A typical bale can cover a 10' x 10' garden with about three inches of hay. Less desirable than hay be-cause they tend to get moldy and may add weed seeds to the garden. The advantage of grass clippings is that they are readily avail-able. Make sure you dry the grass slightly before applying it to the garden and use only clippings from lawns that have NOT been treated with herbicides.
Leaves Tend to mat down and breakdown slowly.
If you must use leaves, shred them first. Paper Includes everything from newspapers, to rolls of paper designed for garden use. Unlike other natural mulches, a thin layer will effectively control weeds. Old newspapers are the least desirable. They are unsightly and tend to blow away.