Great question that we get asked a lot! You will never see hot lava erupting from the top of your trees so no worries about that!
The danger of volcanoes of mulch around the trees is what you don’t see…
“It looks pretty! Why is it bad?” Just like your skin the bark of the tree is meant to breathe. If you wore wet socks for a year – what would your feet look like?
The constant moisture, lack of light and airflow cause ROT. Rot is bad! Especially at the bottom of the tree.
Mulch is supposed to achieve these main goals:
The excessive piled mulch softens the bark of trees and invites insects, rodents and diseases to invade. The lower trunk, unlike the roots, cannot survive long-term with the constant moisture trapped by the collar of mulch. It is the equivalent of planting a tree too deeply. Mulch rings should be wide, not tall and deep.
Another issue besides rot is if you pile mulch too thickly above the roots, the existing surface roots are suffocated and new ones grow into the mulch. Not only does that leave them at risk of drying and dying when the mulch decays, but the roots grow across the stem, potentially strangling the tree to death.
Concerned about your tree? Have our ISA Certified Arborist evaluate your tree. (978) 706-1038.