Possible disease of Deborah Norway Maple
I have two DNMs, each 2 yrs. old, trunk diameter 12". They were planted the spring before cicadas hit and the next summer we had a drought. Poor things! They both have long, narrow slits mainly on the branches. The trunks seem to be okay for now, although one shows bark starting to loosen and two openings are visible. I don't want to lose these trees. Is this something to be concerned about and what can I do? Thank you.
Here is a few links with more information.