Question
My 20 yr-old White Ash was hit by a power tool when my fence was installed 4 years ago. About half of the tree bark near the ground was peeled off, the area that was hit by the power tool.That area is now bald. The tree seemed to be ok for 3 years, but this year, many branches have died. Someone told me that that bald area at the base no longer can transport nutrients to the tree. How can I save the tree? Is there something I can paint it with to restore the moisture in that bald area? Please help, and thanks so much for reading this.

Answer
Hi Helema, I am afraid there isn't a fix.  When the bark is destroyed, food produced in the leaves can't get to the roots and overtime, the roots die off and the food stored in the limbs is depleted and the limbs begin to die.  The other side of the tree should not be affected, so your tree is not going to die unless you have developed a secondary problem.
Don't paint anything on the wound.  Leave it open, exposed to air and sight so you can monitor it for insect or disease issues.
If you see any pinholes, sawdust or sap oozing, spray the damaged area with an insecticide suitable for borers.  Jim