Over-mulching leads to slowly strangulating trees and bushes by piling mulch on the roots where the tree takes in oxygen.

 Here are recommended standards for mulching around your trees:

(1) Mulch must not exceed 3 inches in depth at any point around the base of trees and must be totally flat, not mounded.

(2) Mulch must not come into contact with tree trunks and must be a minimum of 3 inches away from base of trunks.