Industry News: Bark and Trunk Concerns

Q: Is this a fungus? (Photos)

Thursday, September 22, 2016  

Q: Our large, very old oak tree has what I think is a fungus on its bark that looks a bit like melted chocolate. We live in southwest lower Michigan. The tree has leafminers and twig girdlers as well. Might this have something to do with them? Please see photos below:


A: Since the type of oak, or any other conditions such as the texture or smell of the growth aren't provided, a certain diagnosis can't be given. But, if the “black mass” is hard, it may be heartwood decay. If it is "fluid and weeping,” it may be a sapwood infection.

The affect of a severe leaf miner/twig girdler infestation may lower the vitality in this oak and provide a gateway for other organisms to “invade.” Tree vitality is the first line of defense; the insect issue is easily controlled.

Contact your local Consulting Arborist using the ASCA Find A Consulting Arborist.


Responder: Jeffrey Ling, RCA, #337, Fort Wayne, IN