By Diana Lockwood / For The Columbus Dispatch
Although they don’t spew ash or ooze lava, mulch “volcanoes” wreak their own kind of havoc.
Mounded against tree trunks in sloping piles suggesting a miniature Mount St. Helens, too much mulch can injure or even kill a tree.
That’s just one of the morsels about mulch that Eric Brownlee, a certified arborist and manager of the Columbus office of Bartlett Tree Experts, offered during a recent phone conversation.
The takeaway: Applied correctly, mulch can be a tree’s best friend; incorrectly, the tree will wane.
“Trees that have volcano mulch will produce roots that circle the tree,” he said — roots that might eventually choke the trunk.
Because such roots can end up impeding the flow of water and nutrients, “it’s just like if you have a rubber band really tight on your wrist.”
In addition, volcano mulching prevents air from reaching the bark.
“The trunk of a tree isn’t designed to be consistently moist,” he said.
Chronically damp bark can rot, inviting pests and disease.
What’s a well-meaning, mulch-happy homeowner to do?
“Make sure that the root collar is exposed,” Brownlee emphasized.
He called this segment the “ankle” of a tree, the point where the trunk flares out near the surface of the soil.
A layer of mulch should actually thicken as it transitions away from the trunk, not toward…