I have a cherry tree in my front yard that's not doing too hot lately. A general location would be Southern Ontario, Canada (zone 6a). I'm a bit worried that it has gotten cytospora cankers but after looking up the photos online, I'm not 100% certain. From what I've read, cytospora leads to amber sap oozing out (which my tree does have) and leads to sunken bark.
Currently my tree has a few wounds?? of which 2 is oozing a small amount of amber sap. It appears to be ruptures of some sort between where the tree trunk and larger branches meet. The bark in those areas are somewhat swollen (and split?) and has turned a dark brown. No other parts are affected (i.e. aside from where the branches meet the trunk, no other parts of the trunk is affected) and all leaves appear to be fine at the moment.
At first I was quite worried when I first saw it, but after a week or so it seemed to have gotten a bit better. (It's been much rainier and humid this summer, so I thought that the weather might have been causing the tree some stress.) It seems to have gotten a bit worse from last week though after a week of heavy rainfall. Should I be worried? And if so what could this be/what can I do to help it?