Bark damage to a Japanese Maple

(Question)

I live in North York just about 10 mins away from the TBG. We have a 15 year old Japanese tree in our backyard. I recently noticed that a portion of bark approx. 10” by 4” has been stripped/eaten away, I presume, by an animal. Could be a ground hog, skunk, raccoon, smaller rodent all common in our neighbourhood. Chicken wire was put up to protect the tree from further damage. This year I have noticed, also, that the leaves on our tree have shrivelled and are curled somewhat. This has not occurred previously. I do regularly water the tree. Two questions: 1) What do I did not protect the damaged area of the tree. Any wound wrapping or other recommendation? 2) What is causing the leaves to curl and shrivel?

(Answer)

The Toronto Master Gardeners get many questions about Japanese maples.  This year have been many about curling and brown leaves.  Here is a link to a previous question about the causes and treatments of that condition:

https://www.torontomastergardeners.ca/askagardener/japanese-maple-leaves-brown-and-curling/

You could consult an arborist who might be able to pinpoint the cause of the curling in your particular case.

With respect to the bark damage, you have taken the right step in protecting the trunk with chicken wire to prevent further damage.  Note that if more than half of the trunk has been girdled, the tree may not survive.  Trees protect themselves from damage to the bark creating a barrier to protect the healthy wood from the wood which has been damaged.  It is not necessary to apply a wound dressing or similar product.

There are several steps that you can take to protect your tree from further damage.  Firstly you can coat the trunk of the tree with an animal repellent which will discourage animals from eating the bark. Note however that under the Ontario Pesticides Act, the only permitted active ingredient in such repellents is capsaicin.  You can also wrap the tree for winter (which animals are most likely to want to eat the bark).  This can be done with a tree wrap or tree guard which you can get from your local garden centre or hardware store.  These products are applied in the fall, left on for the winter and removed in the spring.  When applying make sure that you go at least 5 or 6 cm below the soil line.  If you are concerned about damage during the spring and summer, you can continue to protect the trunk with a chicken wire cage, or replace with a galvanized hardware cloth cylinder (6-8 mm square mesh) which may be more attractive as a permanent solution.  Note that it is very important when caging the tree to make sure that the cage in not touching the trunk, as otherwise it may start to cause damage to the trunk.

The following links provide some general care information for Japanese maples: Japanese Maples,

Care of Japanese Maples

August 26, 2021