Too Much Mulch Is Not A Good Thing
Mulching around your trees can be beneficial for many different reasons. It looks great, helps to keep the weeds at bay, and can add nutrition that your soil and the root systems of your trees may be lacking. A common mistake, however, is over mulching around the trunks of your trees.
Too much mulch against the trunks of trees can make the bark rot. An excess amount of mulch also creates a great place for insects and rodents to hide, leaving your trees vulnerable to attack. Too much mulch can also limit the amount of oxygen and other vital nutrients that your trees’ roots receive. Once a tree shows signs of injury, it may be too late and all efforts to save it will be in vain.
To properly mulch around the base of your trees, place it within a couple inches of the trunk. Try to not let mulch make much contact with the tree. Two or three inches of mulch will provide the benefits without endangering your trees’ health.
Notice the darker bark around the base of the trunk. This tree was originally over-mulched and the bark began to rot.