Can I Shave Down Roots?

Q: We purchased a house with a big corner lot. I have Bradford pears on one side of my lawn and five cherry trees around the corner. Some of their roots protrude from the ground. Can I shave them down an inch or two so my mower can safely pass over? 

A: You will create lots of problems if you shave off the roots. First, removing the protective bark around the root will expose it to infection. The root could die or it could transfer disease to the rest of the tree. If a root dies, it affects the anchoring structure of the tree and its ability to absorb moisture and nutrients. Second, if you shave them, the roots may not die but could form callus tissue. Particularly on Bradford pear and cherry, this damaged area will send up small sprouts which you’ll constantly have to remove. Even if they roots don’t die or form callus tissue, they will inevitably grow bigger and you’ll be back to shaving them down in a few years. My advice is to buy a truckload of sandy loam topsoil and spread it under the tree in a layer thick enough to hide the roots and mow unimpeded.