pine trees dying-cytospora canker?

Asked February 18, 2019, 2:48 PM EST

Greetings, We have about 8-10 pine trees that seem to be quickly dying. From my research online it seems they may have a fungus disease like cytospora canker? Five of the trees are blue spruce. They seem to be dying from the bottom up. All the branches are thinning out. Is there anything we can do to save them? My guess from their height they are at least 15 years old. My second question is we have an Ash tree that we had treated to prevent the Emerald Ash borer beetle. Do you believe this treatment can prevent the insect from killing the tree? It was recommended we treat the tree every year which is around $350 for a yearly injection. Thank you in advance, Jessica

Baltimore County Maryland

1 Response

Blue spruce is not native to our area and often has difficulties over time in Maryland.
There are significant disease issues that occur, often in conjunction with stress issues like drought.

Here is a page about the most common disease issue, Cytospora canker.

Rhizosphaeria needle cast is another common problem in these trees.

Here is a related article by our plant pathologist.

Unfortunately, there is nothing curative that can be done to reverse the symptoms in these trees and eventually they should be taken out.

Ash trees need to be treated every 2 years to control emerald ash borer. Emamectin benzoate is the best treatment available currently. If more than 1/3 of the tree canopy has died, however, it is too late to treat and you should have the tree taken down. Ash trees become brittle quickly when they die and they can be hazardous. There is more information here on our website: