Opps, lawn mower hit

I have just knocked off half the bark from a four year old crab apple tree. 1.5" Diameter trunk. Is there a way to help restore this bark or cover the exposed area to save the tree.
Or do I have to do anything, will it heal it self without my intervention.
Not a Green Thumb yet.

 

The wound will get covered over by new wood growth in a few years. Don't add anything else, 'wound paints' have been found to do more harm than good.

 

Thanks for the good advice Michael. I will leave it alone.

 

Perhaps you could lay down some sort of physical barrier around the tree to prevent further tree-mower encounters. Make a flower bed around the base of the tree---that sorta thing.