Im in North York. I have a Cherry Tree about 20ft tall in the backyard surrounded by two towering pines. It has flowered nicely, and is producing little green balls, so seems like cherries are coming. The problem is some branches are dead black looking with spore spotting and the trunk has oozing sap and looking darker in colour, the branches farther up to the sky look healthy and even the sick looking branches have produced flowers and what looks like to be cherries this year. what does it have, what do i do?
Thank you for contacting Toronto Master Gardeners with your question.
Although it is difficult to see details of the bark, the disease appears to be either a black knot or a bacterial canker.
Please refer to the links below for more information and references.
Black knot
- https://www.omafra.gov.on.ca/IPM/english/tender/diseases-and-disorders/blackknot.html
- https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/fungal-spots/black-knot.aspx
Bacterial canker