Have a customer who has two bradford pear trees that are about 1/2 way grown. I am going to edge beds, mulch, trim hedges, etc. The two bradfords have huge mulch piles a the base. I would say 12"-15" up the base of the tree. They have been like that I know 2 years now. I have told the customer that that is not a good idea and should be corrected. My question is: Remove old mulch and expose base of tree that has been covered with the mulch? I "scraped" back some mulch and exposed some small roots that have developed on the trunk of the tree that has been covered with mulch. So better to leave well enough alone and add to the mulch volcano or remove all the old mulch? P.S. Planning on extending the radius of mulch to catch up with the growth of the tree.