I want to take a moment to explain proper mulching techniques for trees.
I see it all the time in suburban front lawns, a tree poking out of the top of a mound of mulch. This is one of the worst things you you could do for the health of your trees. Mulch should never touch the trunk of a tree. If the tree is young mulch should be about 3 inches away from the trunk and as it matures it should be kept about 6 inches from the trunk.
You may have heard the term “mulch volcano” which basically refers to a mound of mulch with a tree coming out of the top like the eruption of a volcano. When you mulch around a tree it should be like a doughnut with the tree coming up in the middle of the hole. try to keep the doughnut somewhat flat and about 3 inches deep.