I have a Japanese maple tree. Looks like an animal (raccoon possibly) scratched off the bark at the base of the tree in the Spring on 2020. It grew zero leaves.
Will it return or is the tree dead?
Thank you for contacting the Toronto Master Gardeners.
The layer under the bark of a tree is called the cambium. It contains the xylem and phloem cells that transport all the water and nutrients up the tree and the carbohydrates (food) from the leaves out to rest of the tree. When the entire trunk is girdled (encircled) the tree is unable to get water and nutrients and the tree will die.
When a tree has damage but still has some cambium left to move water and nutrients and food around it will continue to struggle along at least in the short term. The tree builds a barrier around damaged areas which isolates the damage from the tree. This way it protects itself from infections and routes the flow of its nutrients etc. around the damaged area. So yes, the tree does fix itself but if the damage is too large the tree cannot grow and thrive and will eventually die.
If 75% of your tree is girdled, I fear that is too much for a young tree to compensate for. This together with the fact that your tree did not put out any leaves last year is a sign that your tree is most likely dead. You can check if any part of your tree is still alive by using your fingernail to gently scrape the bark on the branches and trunk, starting at the tips and working back toward the base of the tree. If you see green, healthy wood below the bark this means that this part of the tree is still alive.
The most likely culprit that caused damage to your tree was a rabbit. A hungry rabbit will strip the bark off trees and even chew roses to the ground. Next year, when preparing for the winter you may want to protect the trunks of your young trees to avoid this happening again. When protecting your trunk in the winter you need to go higher than the snow line. Rabbits are just as happy to sit on the snow and eat higher up as eat at the base of the trunk. There are commercial protections you can buy to wrap around your trunk or you can fashion a cage with chicken wire to keep the rabbits away from the trunk. If you wrap your trunk make sure to unwrap the tree in the spring since this will trap moisture against the trunk which can cause other problems. Your local garden center will also sell a chemical deterrent called Skoot, which can be painted onto the trunk in the fall. Again, make sure to paint well above the snow line.
January 12, 2021