Should I worry about spruce rust?

Asked November 4, 2015, 2:02 PM EST

I have a blue spruce in my yard that was planted by the previous owner so it's probably 20 years old. The inner needles are turning yellow with black dots and the tree is looking very unhealthy. I've Googled the symptoms and found Spruce Rust on an extension site, so I'm wondering if I need to be concerned that the disease might spread to other trees. I also spoke to a botany professor who told me to looking for signs of a boring beetle, but I did not find any -- there's no "sawdust" on the ground nearby and the tree is still making buds.

Charles County Maryland blue spruce trees

1 Response

Blue spruces do not live very long in Maryland. The weather here makes them susceptible to all sorts of diseases for which sprays are not curative. https://extension.umd.edu/hgic/cytospora-canker-spruce
https://extension.umd.edu/hgic/evergreen-needle-cast-diseases-trees-and-shrubs
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/spruce-tree-diseases/spruce-needle-rust... If your spruce only has spruce rust, you might not want to be too concerned. It is likely however, that it has other problems as discussed in the previous links. The diseases that impact blue spruce will not affect many other types of trees. If you have multiple blue spruces, all will probably eventually be affected, but removal of sick ones will be beneficial to the others if they are not yet affected. vw