‘Mulch Volcano’ is term used to describe a deep pile of mulch around the base of a tree or shrub that forms a mound or volcano shape. You see them everywhere, especially on or around commercial properties, as grounds crews and gardeners alike are busy applying hardwood mulches to beds, borders and trees.
Generally speaking, there are many benefits to mulching, but I wonder if people see these volcanoes and think it s ok to copy this? It most certainly is not and there are several reasons why one should avoid it.
The consequences of overmulching trees and shrubs:
Piling soil, mulch, or both, against the trunk flare has been shown to prevent needed gas exchange causing the inner bark tissue (phloem) stress, dysfunction and subsequent root stress.
Overmulching can promote excessive soil moisture which can lead to root rot.
Fungal and bacterial diseases, crown and butt rot can also be caused by excessive mulching.
Mulch that touches the trunk of a tree can lead to rodents chewing on the bark as well as insect problems.
So, what s the proper way to mulch? Follow these guidelines:
Apply the mulch to the surface of the soil anywhere from 2 to 4 inches thick.
Do not allow the mulch to touch the trunk or stems. Keep it about 3 to 6 inches away.
Apply the mulch from the center of the tree to the dripline if practical. Otherwise, at least a 3-foot radius around the trunk.
