As spring turns into summer this month, homeowners (or their landscapers) will be practicing the annual ritual of laying mulch down throughout their properties.
Not only does a fresh layer of mulch give your garden and the area around trees a clean and freshly-planted look, it is also one of the best ways to maintain soil moisture, insulate roots from both heat and cold, and minimize the need to weed.
But there’s one instance where mulching can actually be harmful to a tree, and it’s one that’s widely practiced for those who don’t know any better: the mulch volcano.
Judith Robinson, manager of the Princeton Farmers’ Market, warns against heaping piles of mulch against a tree’s bark — creating a mountain or volcano effect.
“Apparently 85 percent of the mulching methods landscapers presently are using are actually weakening and eventually killing your trees,” said Robinson in a letter to the Echo. “Everywhere I go, I see the black mulch in dense high piles around trees and bushes — rotting the bark surfaces, encouraging surface root growth, discouraging deep supportive root development, preventing penetration of needed moisture and promoting extensive root girdling.”
The N.J. Division of Parks and Forestry offers advice for people with trees currently trapped in a mulch mound. “If your tree is in a mulch volcano, please don’t remove the entire volcano at once. Removal of a mulch volcano all at once might further damage your already stressed tree. We recommend you seek the advice of a N.J. Certified Tree Expert.”
A list of providers and other tree care information is available on the Division of Parks and Forestry website at state.nj.us/dep/parksandforests/forest/community.
—Bill Sanservino
