You’ve probably seen the mounds of mulch around the base of a tree – maybe even in your own yard.
This mounding of mulch is a common practice and is called “volcano mulching” in the community forestry world.
And it’s a habit that we need to correct.
Mulch around the base of a tree is a good idea; it helps the soil retain moisture, it keeps the roots of the tree coo and helps disperse weight and protect the roots from compaction.
However, mounding the mulch around the trunk of a tree creates problems. The bark of a tree needs air and light and mulch shades the trunk and creates a moist environment that can promote insect infestation and rot.
It can also encourage roots to grow upwards toward the moisture and encircle the base of the tree, causing the tree to essentially choke itself to death.
The best way to mulch a tree is to leave a space around the trunk, about a hand-width between the trunk flare and the mulch.
The mulch should be mounded in a circle away from the tree, creating a basin for water to collect and slowly seep into the ground, and should be no more than two to four inches deep.
The mulch will keep the roots cool and preserve moisture in the root zone instead of around the trunk of the tree.
By properly mulching your trees, you are helping them grow by providing them with nutrients, reducing competition from grass and weeds and retaining soil moisture where it’s needed.
Karen Emmerich is a Town of Warwick Tree Commissioner.