Why Volcano Mulching Can Damage Trees Before Winter

Volcano mulching traps moisture against tree trunks and can contribute to bark deterioration and root problems. Experts recommend spreading mulch in a broad, shallow ring while keeping the trunk and root flare exposed. spacedrone808/Shutterstock

That fresh mound of mulch around your tree might look like you’ve done everything right to protect it before winter, but it could actually be causing damage that costs hundreds or even thousands of dollars to fix.

The practice is called volcano mulching, and it’s surprisingly common in residential neighborhoods, commercial landscapes, and even professionally maintained properties.