Spruce (I think) Canker diagnosis?

Asked March 27, 2016, 1:15 PM EDT

Hello! Five years ago my family moved into our home in Otter Tail County. In the front yard was a gorgeous and huge evergreen (I believe it is a Colorado Spruce). I do not have a green thumb. I seriously kill plants on accident all the time. Now I'm afraid that is extending into my yard! I am fearful that the tree might be suffering from Cytospora Canker. I made the mistake of cutting some lower branches off but didn't follow what I now understand is protocol (dry season, washed blade for each branch, etc). I was wondering if my pictures might confirm a canker diagnosis and if there is a best course of action to follow. I understand canker isn't treatable, but am wondering how many years I have before I need to remove this tree. :( I realize an answer may not be possible because of too many factors but I'm trying to determine when and if I should remove it (sooner or later). Thanks! Sheri

Otter Tail County Minnesota cytospora canker

1 Response

I have had this problem for many years also in Ottertail County (NYM), control of Cytospora canker requires that all diseased branches be cut back to the nearest living laterals or to the trunk of affected trees. The bark should not be injured unnecessarily, since the fungus may enter through wounds resulting from injuries. When the branches or trunks of affected trees are wet; spores exude from cankers onto the surface of the bark. Pruning at this time should be avoided, since pruning tools may spread spores. Because of this, only prune during dry periods. Since weakened trees are susceptible to this disease, fertilizing to stimulate vigorous growth may help to combat Cytospora canker. Fertilizing may also stimulate new growth that may fill in small vacant areas in the trees but large dead areas seldom fill back in. Both too much and too little water are stresses that can weaken spruces. Make sure there is adequate drainage and water the trees during droughts. There are no fungicides that effectively control this disease.