Stripping of bark off my cedars

(Question)

20160814_143000For a few years now, creatures (?) have been stripping bark off the cedars which beautifully separate our yard from our neighbour’s. We live in Leaside. The cedars are large and gorgeous. Unfortunately the bark is being stripped from them and I asked for advice from a local nursery who sold me white plastic covers for the trunks. The had no idea what was happening and how to prevent it except for the covering.
The stripping has continued so I have covered the trunks with aluminium foil. Because this protection looks a bit gross I have sprayed both coverings with brown paint which looks not too bad. Recently I have had another bark stripping attack which as you can see from the picture is above the coverings. I am very afraid that I will lose the cedars which are a major feature to our back yard. So I have several questions:
What animal is doing this?
What can I do about it? How can I stop this destruction?
Is the covering OK for the tree?
Is the spray paint on the covering OK?
Any other suggestions to prevent further damage to the trees.
See attached picture. I would be happy to provide more.
Many thanks for your assistance

 

(Answer)

Thank you for contacting Toronto Master Gardeners.

It is so sad to see a beautiful old cedar being attacked. Squirrels are most likely the culprits. The shredding from the bark can be used for their nests and they have been known to also chew on it.

Stopping squirrels in Toronto can be a real problem as there are so many of them. If you remove them, others will just take their place. The best deterrent, I have found, is owning a dog. This is not an option for everyone.

On the internet there are several remedies that people apply to the bark to deter squirrels. Sometimes these remedies can attract insects so you need to be careful when trying any of these quick fixes out. You can end up with a worse problem than you started with. Your best bet it to contact an arborist to see if they have any tips and tricks that have worked for them.

I do have concerns with wrapping the trunk of the tree. When covered, the bark can not breath properly and there is a large risk of capturing moisture in the bark. The moisture can break down the bark as well as give insects and infections a perfect environment for a an attack. The cambium layer of the tree is just below the bark. This is the tissue that allows nutrients, water and carbohydrates to circulate through the tree. If you have totally surrounded the trunk it can lead to the tree being girdled (a damaged layer of cambium all the way around the trunk) which can lead to the death of the tree. If you must wrap the tree you need to use something that allows the trunk to breath. As a stop gap measure something like chicken wire might help.

The best thing you can do at the moment is to ensure the tree is as healthy as possible so it can defend itself against anything that may attackthe damaged bark. keeping the tree well watered will help it stay strong. Putting a thick layer of mulch around the tree will help keep the moisture in the soil. be sure to put about 7 inches of mulch around the base of the tree but ensure that the mulch is not touching the trunk. ( this leads to the same issue of moist bark and possible breakdown and infection.) The mulch should be a donut shape rather than a volcano around the tree. Keep a close eye on the damaged areas of the tree so if there are any signs of disease you can react quickly.

I am including a link below on diseases and issues with Cedars to help you know what issues you are watching for.

Good Luck.

www.guelphlabservices.com/files/PDC/006Eastern%20White%20Cedar.pdf