Mulching around your trees is a common practice intended to enhance the look of the landscape as well as create beneficial conditions for trees. Although the process appears simple there are right and wrong ways to mulch. Far to often I see mulch piled very high and against the trunk of a tree resulting in what is called 'volcano mulching'. A properly mulched tree should have 2''-4'' of mulch with the trunk and base of the tree free from contact with the mulch. Excessive amounts of mulch can cause soil moisture conditions that may lead to the development of root rot. The video above goes over all of the basics of proper mulching and associated benefits.