Benefits of mulching around trees

Mulching can be helpful around young trees like yours to create a weed free zone around the tree. This helps protect the tree from mower and weed eater damage, and reduces the tree's need to compete with surrounding weeds for water and nutrients. Also, a thick mulch can prevent "heaving" when repeated frost and thaw cycles can push young trees out of the ground.

When to apply mulch

Unless there is already a heavy layer of mulch or compost around the base, it should be fine to add one. Avoid adding it in a volcano shape mounded up around the trunk. The mulch should be an evenly distributed layer with a small "bowl" or depression right around the trunk.