[header] How to mulch around a tree [title] Shovel away old mulch, dirt, and rocks. [step] Shovel away all the old mulch, debris, and rocks so that you can see the tree trunk. A " mulch volcano " occurs when mulch is piled up year after year on the base of a tree. 
Mulch piled up at the base of a tree is detrimental and starves the roots of needed oxygen. [title] Cut up-growing roots with pruners.