Just visiting the local grocery store makes me grimace. It’s all about the trees there. Last year, landscape and lawn care companies tidied up borders, trimmed and pruned shrubs at the grocery and then they piled at least a foot thick layer of mulch against the trunk of all the trees around the parking lot, a process that has been dubbed ‘volcanoes,’ or ‘turtle mounds.’
I’m always amazed to see a sight like this. For decades, arborists and extension experts have railed against such practices because it will sentence a tree to a slow death. Why we still see everywhere it is a mystery to me.
Not only commercial sites, but old trees and new trees in neighborhoods within a mile of my home are mulched with volcanoes. The mulch volcanoes have settled over the fall and winter months, but still piled high against the bark.
Mulch done right is beneficial for a tree. It prevents weed growth, protects bark from a weed wacker, helps retain moisture, and helps to moderate soil temperatures in all seasons. But the volcano mulch piled against the bark of tree, especially young trees, will soften the bark and invite the invasion of rodents, insects, fungus, rot and the suffocation of the trees’ roots.
I’ve been taught to think ‘doughnut’ when mulching a tree and limit the mulch to two, three or four inches deep… max. Once I apply, I pull the mulch away from the trunk for about five or six inches until the root flair is visible.
It’s a puzzle to me why volcanoes are so popular. Is it that the professionals don’t know better or do their clients prefer the volcano look? It frustrates me and as a frustrated Charlie Brown would say, “Aaugh!”