Mulching is one of the best thing you could do for your trees. Properly mulched tree will receive more nutrients, help with retaining water and moisture, and reduce weed growth.  

However, improperly mulching or creating "mulch volcanoes" can hurt the tree. Piling mulch at the base of the tree could lead to insect and disease problems. Overmulching will also damage the bark and trunk of the tree by having too much moisture which could lead to root rot making the tree unstable. 

• Mulch wide, the depth of the mulch does not benefit the tree. Mulching wide protects the tree's critical root zone. 

• Avoid using more than 2"-4" of mulch.

• Do not pile the mulch against the trunk of the tree, keep the mulch 4" away from the trunk, so that the root flare zone is visible.

• To refresh the look of mulch, lightly rake the top layers of the mulch, or simply remove the old mulch and replace with new mulch. 

• Do not use fresh wood chips for mulching around young trees, fresh woodchips has higher acidity.