Is my tree dying or just diseased?

Asked April 10, 2018, 2:08 PM EDT

We recently bought a home in the Woodmoor neighborhood of Silver Spring. I've been told by the neighbors that they believe our tree in question is a plum tree. The tree is laden with a black wrap around type of fungus and it also has several places where an amber-colored sticky substance is oozing from the tree. I've been told the tree is dying and beyond help, but I'm trying to determine if there is something that can be done to save it, or if it truly is at the end of the life cycle.

Montgomery County Maryland

3 Responses

You did not mention if the plum tree is an ornamental or fruit tree.
Gummosis - . The presence of gum or sap on cherry trees can be a natural response to defend wounds on the tree caused by things like bark cracks, insect feeding, old pruning wounds, cankers, or drought. This is the tree's natural response to a source of stress. There is not much you can do other than prevent additional stress. Prune out any dead branches, rake fallen leaves to prevent any overwintering fungal spores, and water the tree during dry periods to maintain vigor. Make sure mulch is no thicker than two inches and keep away from the base of the trunk.

Black galls - Based on your photo this looks like black knot, a fungal disease. You may see this on plants in the genus Prunus such as plums, cherries, etc. See our website for photos and more information.
All you can do is prune at least 4 inches below the gall/growths during dry weather. Discard in the trash.
If there is a wild cherry growing nearby, and you are able to, you can remove and destroy it. This tree (and others that will be further away) serve as a host for the pathogen. If the tree is badly infected, you may want to consider removal.


Thank you for the response. I am not certain if the tree is ornamental or bears fruit, but I believe it to be a very mature tree either way.

I looked at your link for black knot and yes, that is exactly what is on our tree. I am in the process of pruning as much as I can and will hope for the best. Unfortunately, though, I cannot reach the top of the tree. So, I suspect in a year or two we will have to take it down.

Thank you again, this has been very helpful.