Question
I have a two years old apple tree.  It was cut off the bark around the trunk ( by a grass trimmer )about three inches.  It is still look green and normal, but some people said it is dying.  Is it right?  I do not believe so! Please give me your opinion.  Thank you.

Answer
If it is still green it is not dying. Normally you can girdle the tree if the bark is cut down to the woody cells all the way around the trunk. I spray the area with an insecticide called Merit to prevent borers from entering the wound. The then mulch around the tree with not more than 3 inches deep of organic mulch not piled up on the trunk. This will help hold moisture and the roots and keep the trimmer away from the trunk.