Birch tree with split bark


Asked about my birch tree at Canada Blooms. Suggested I send in picture. Birch tree is 40 years old. Two years ago bark started to split from ground up. Last year split widened dramatically. Located in south Mississauga (north of Dundas). Split is on west/north west side of tree. Otherwise healthy except for some broken limbs suffered in ice storm few years ago. Should I be concerned? What, if anything, should I do to stop splitting, foster healing, etc. Any help would be appreciated.


Thank you for sending in a photograph of the problem with your birch tree.  I cannot tell from the photograph if the injury has begun to ‘callus over’.

While the birch tree is not on the ‘at risk’ list of trees for splits and fissures caused by cold temperatures, it can be affected.  These frost cracks occur when the inner and outer wood in the tree’s trunk expands and contracts at different rates when the temperature changes.  They often originate at a point in the trunk where the tree has been injured in the past.  It is not necessary to apply anything to this injury.

Do give the tree the best conditions possible to continue growing healthily.  Top dressing the base of the tree with compost and providing it with water during drought periods would be beneficial.  Take care when trimming around the tree to ensure that no mechanical damage occurs.

Cornell University has a very good fact sheet on bark splitting on trees.

If there is no indication of the injury beginning to callus over, it is necessary to consider the possibility of disease or mechanical injury.  Birch trees are susceptible to a number of fungal infections that affect the tree’s trunk.

This injury needs to be watched – if a callus does not form, a certified arborist may need to be called in.