According to the Arbor Day Foundation, there are good reasons to use wood mulch around your trees.
- Mulch helps trees retain water by keeping the roots moist.
- Mulch keeps weeds down to help prevent competition for root space.
- Mulch prevents compating of soil.
- Mulch reduces damage from lawn mowers.
An article from the Arbor Day Foundation tells how to prep the area to mulch the right way:
- It's important to remove any grass withing a 3-foot to 10-foot area around the tree. The size of the area depends on the size of the tree.
- Add wood chip mulch 2-4 inches deep within that circle.
- Mulch should not touch the trunk of the tree.
Mulching improperly can harm the tree. Mulch should not be mounded up around a tree, but instead, kept away from the base of the tree. This video from This Old House shows the proper way to add mulch and to fix a tree that has been over-mulched.