Pruning a Muskoka white paper birch tree of 35 years

(Question)

I need to trim my birch as its tall and I worry that branches may break with an ice storm . last time it simply bent over and straightened once the ice fell off. I worry that I might shock it or kill it as it will bleed sap. this tree is my baby.

(Answer)

Thank you for contacting Toronto Master Gardeners.

This is a timely question because extreme weather events such as ice storms are occurring with greater frequency. Betula papyrifera or Paper Birch are lovely trees so it is understandable that you want to preserve it.  To make your birch more resistant to ice storms:

  • Prune the tree on a regular basis to remove structural weaknesses – for example, remove narrow-angled or weak branch attachments to minimize risks. The best time to prune a birch tree is during their dormant period which is from late fall to late winter, once it has lost its leaves and before bud break in the spring.
  • Do not take off the top of the tree or over prune it. This will create a structural weakness that may fail under the pressure of ice and wind.  Pruning out any dead, diseased or dangerous branches first and then pruning for size reduction and shape.
  • You mention that the tree is large. If you think pruning is necessary and you are cautious to tackle the job yourself, consider hiring a certified arborist. To find an arborist in your area, visit Landscape Ontario’s website, please click here

If an ice storm occurs:

  • Don’t shake the tree to remove snow as this could cause damage in the form of branch splintering or breakage.
  • Assess the tree for any immediate hazards and call in a professional arborist to deal with the tree if you deem it to be dangerous to you or to property.
  • If there are no immediate hazards, wait for the snow to melt.
  • Once the snow has melted assess for tree damage.  For information on what to assess and how to address ice storm damage click here.

We hope you find this information helpful.

November 12th, 2023