There is a lot of excellent information available online regarding the why’s and how’s of proper mulching. We often refer our clients to this PDF published by the International Society of Arboriculture.
We won’t cover the same material here, but we will give you some real examples from around the Pioneer Valley. In fact, it was a recent trip to the Hampshire Mall in Hadley, MA that prompted us, yet again, to think about the importance of proper tree mulching. We spotted mounds of mulch, piled up around the trunks of all the trees in the parking lot.
Mounds of mulch piled up around the trunks of every tree in the parking lot at Hampshire Mall in Hadley, MA
Mounds of mulch piled up around the trunks of every tree in the parking lot at Hampshire Mall in Hadley, MA
You have surely seen this yourself, especially outside new construction buildings (looking at you, Greenfield Savings Bank, on King St in Northampton!), and in your neighbors’ yards.
While mulch has many excellent benefits for trees, when done incorrectly it can actually be worse for the tree than no mulch at all. Why? It invites many different soil, insect, disease, and growth problems.
About one year ago, our family was having dinner in Chicopee and saw a crabapple suffering under the volcano mulch. It was slowing dying, as you can see in this picture below.
Volcano mulch piled up against a young crabapple in Chicopee, MA (2017)
With my son as my helper, we did some digging to rescue the tree. Good thing we had some gloves in the car!
Digging out the volcano mulch in Chicopee (2017)
This crabapple had been buried for a while. Its primary root system rotted away (this is called root rot), and a second root system took its place.
You can see the secondary root system that grew on the trunk, in the black area we uncovered.
This is how deep the trunk was buried, completely unnecessarily.
We returned to the same tree just last week, almost exactly one year later. Of course, the landscaping crew the landowner hired has done their annual mulch dump, so the volcano shape is back. But check out the difference between the crabapple we dug out and the crabapple behind it:
The Chicopee crabapple we previously dug out of the volcano mulch. Looks much better now (taken 2018), despite new volcano mulch added this spring.
Crabapple next to the one we unburied a year ago (taken 2018), slowly dying.
Now let’s go back to those trees in the Hampshire Mall parking lot and do a closer inspection.
Close up of trunk buried in mulch; Hampshire Mall parking lot, Hadley
You can see the structural defect in the trunk (above), about a foot from the top of the mulch pile. And even at the very base, buried partway into the mulch, you can see more areas of rot caused by improper mulching. Not only does this leave the tree more susceptible to disease and pests that will attack a weakened tree, but it will eventually become a safety issue. The trunk and base are compromised, which means that adverse weather conditions, such as high winds, heavy rainfall, etc., could cause the tree to fail. Whether that’s in the next 5 years or 10 years, we don’t know, of course. Fortunately this tree is not very tall, but it is in a high-traffic public space, and it should be monitored closely to prevent any damage or injuries.
We hope these examples are helpful in understanding the importance of proper mulching. While the effects may not be immediate and dire, they are serious and affect the long-term health of the tree. For homeowners, this can affect your wallet and your property value, too. We strongly recommend you do your trees and yourself a favor, and just say NO to volcano mulch.
Want to get mulch rings properly installed for your trees? Give us a call at 413-835-6052, and our ISA Certified Arborists will be happy to assist you.
