Proper Mulch Can Improve Health of a Tree

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:

1. 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. 
2. Add wood chip mulch 2-4 inches deep within that circle. 
3. 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.