Dawyck Purple Beech – cracked bark

(Question)

Hi there – I live in Toronto (mid town), and planted a purple beech tree about 3 years back (early Spring).

Last year the bark started to crack at the base and I thought that was the tree trunk growing.

In the last two weeks, I noticed a section of leaves start to prune, and I’m now concerned the tree has a disease… I was hoping you could evaluate the images (will only allow me to upload one) and share if I have reason to be concerned? The tree has grown new branches and leaves each year thus far.

(Answer)

Thank you for contacting Toronto Master Gardeners about your Dawyck Purple Beech (Fagus sylvatica ‘Dawyck Purple’) and for adding a photo with your question.

When bark splits, this can be a result of a physical injury from something like a lawn mower, or even due to fluctuating temperatures in winter, creating a problem called winter sunscald. This article from the Government of Manitoba does a thorough job of describing this problem, and describes ways to prevent similar damage in future winters. It also describes a problem called frost cracking, but this seems to occur more frequently with older trees, and your tree is still young. Cracks in bark are not in themselves a big problem. The real issue is what enters the cracks, possibly in the form of a pest or pathogen.

The Invasive Species Centre describes both Beech Bark Disease and Beech Leaf Disease that can infect beech trees in Ontario. In addition, beech trees can be impacted by a variety of insects, for example woolly beech aphids as described in this answer posted on the Toronto Master Gardeners’ website.

We suggest you do a careful examination of the tree. Can you see any insects or insect damage? Is there any discolouration on the trunk, branches or leaves which could be a sign of disease? Is there any further damage, aside from the cracked bark and the dead leaves? Based on this information, it will help you narrow down the source of the problem. It will also help you match your tree’s symptoms to one of the diseases described above. or in a follow-up question to the TMG. We would also recommend you contact a licenced arborist, who could assist you with identifying the problem, and work with you to solve it.

You have a lovely young tree, and we hope you can have many more years of enjoyment from it.