Fungus and blue spruce - Ask Extension
I’ve noticed that our blue spruces are losing lower branches to what I think is fungus on the bottom branches and we actually have some that are pro...
Knowledgebase
Fungus and blue spruce #923341
Asked January 05, 2026, 4:14 PM EST
I’ve noticed that our blue spruces are losing lower branches to what I think is fungus on the bottom branches and we actually have some that are probably 2530 feet tall that are dead all the way up to the top. Noticed that we have a large Norway spruce in a group of Norway spruces that one section is starting to get the fungus on it as well. How do I treat those trees to avoid it from spreading to other trees and to higher branches?
Newaygo County Michigan
Expert Response
Hello
From the photos you have attached, the green/gray objects on the branches are called lichens. These do not harm the tree and are actually an indicator of healthy air, i.e., in polluted areas, lichens will not grow. They are a symbiotic relationship between an algae and a fungus and come in various colors. They will grow on live and dead trees, rocks, roads. You can read more about them here: https://www.canr.msu.edu/news/what_are_lichens_and_what_are_they_doing_on_my_tree
As for a fungus or other disease affecting your Norway spruce, it is too difficult from these photos to determine what is attacking your trees. You can try to take and upload here additional photos of the needles (close up and in focus) and the entire affected tree, so we can see what is happening. There is a needle cast disease that Norway spruce is supposed to be resistant to, but it does show what the infected needles will look like. https://www.canr.msu.edu/resources/rhizosphaera_needlecast
Here is more information about needle cast: https://www.canr.msu.edu/news/rhizosphaera_or_not
Or you can also send in a sample (read directions) to the MSU Plant & Pest Diagnostics Lab: https://www.canr.msu.edu/pestid/ for an exact diagnosis.
Thank you for contacting MSU Extension.
From the photos you have attached, the green/gray objects on the branches are called lichens. These do not harm the tree and are actually an indicator of healthy air, i.e., in polluted areas, lichens will not grow. They are a symbiotic relationship between an algae and a fungus and come in various colors. They will grow on live and dead trees, rocks, roads. You can read more about them here: https://www.canr.msu.edu/news/what_are_lichens_and_what_are_they_doing_on_my_tree
As for a fungus or other disease affecting your Norway spruce, it is too difficult from these photos to determine what is attacking your trees. You can try to take and upload here additional photos of the needles (close up and in focus) and the entire affected tree, so we can see what is happening. There is a needle cast disease that Norway spruce is supposed to be resistant to, but it does show what the infected needles will look like. https://www.canr.msu.edu/resources/rhizosphaera_needlecast
Here is more information about needle cast: https://www.canr.msu.edu/news/rhizosphaera_or_not
Or you can also send in a sample (read directions) to the MSU Plant & Pest Diagnostics Lab: https://www.canr.msu.edu/pestid/ for an exact diagnosis.
Thank you for contacting MSU Extension.
