Asked July 03, 2015, 10:59 AM EDT
We have a row of about 15 spruce trees (Black Hills spruce and Colorado blue spruce) that are placed for shelter. I have attached 3 photos that show some damage to a couple of trees and what the full row of trees looks like. We are wondering if there is a disease, fungus, or insect damage. If so what might be done about it? We have contacted a local arborist, but he cannot look at the trees for 6 weeks.
Minnehaha County South Dakota
My suspicion is cytospora canker, a very common disease of blue spruce trees. If you examine the dead or dying branches, closer to the trunk, you should see whitish pitch that has been exuded from the branches. It is caused by a fungus that usually spreads up from the bottom of the tree. About all you can do is to prune out the affected branches, back to the main trunk during dry weather. Make sure that irrigation sprinklers are not spraying onto the trees since this can spread the disease.
Here is a link to some additional information.
Thanks for the reply,
Do we need to spray and fungicide?
There really isn't any fungicide that will do any good. Unfortunately, blue spruce are way over-planted and they are often growing under fairly stressful conditions. Most survive for about 30 years or so then finally really start having stress related problems like this disease.