Thinning spruce branches - Ask Extension
Two of the pictures are showing thinning of a tree trees, one side and lower branches. I believe it’s a spruce tree probably 20 to 30 feet tall. Itâ...
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Thinning spruce branches #925794
Asked March 10, 2026, 4:15 PM EDT
Two of the pictures are showing thinning of a tree trees, one side and lower branches. I believe it’s a spruce tree probably 20 to 30 feet tall. It’s only on one side of the tree. I’ve included those 22 pictures that showed the thinning and then the tree that is right next to it, which is of the same variety looking very healthy. Any ideas on what is causing this issue issue and how to correct it so it doesn’t spread any further on the host tree or the trees located by it. Thank you.
Newaygo County Michigan
Expert Response
Hello,
This is a fungal condition common in spruce here in Michigan, something referred to as "needlecast" due to the symptom of needle loss. It can be caused by several different types of fungus, so if you decide you want to try to treat with fungicides, you will need to get a positive diagnosis of which fungus you need to treat.Â
Before you do go down that road, you may want to decide whether you want to be spending the time and money treating several times per year for multiple years- with sometimes less than terrific results, because the fungicides only prevent further loss.Â
If you are set on protecting the one tree that is not affected, it may be worth consulting an ISA-certified arborist to determine which fungus is affecting your trees. Find one in your area:
 https://www.treesaregood.org/findanarborist Again, this tree would need yearly fungicide treatments to protect the new growth from infestation.
Sometimes removing the most severely affected lower branches can improve the aesthetics of the trees. Choosing alternatives to spruce to plant in the future is also a good strategy.Â
Other practices to keep your spruce healthy:
Read more about the disease and alternatives to spruce:
https://www.canr.msu.edu/news/what_is_spruce_decline_and_what_should_you_do_about_it
This is a fungal condition common in spruce here in Michigan, something referred to as "needlecast" due to the symptom of needle loss. It can be caused by several different types of fungus, so if you decide you want to try to treat with fungicides, you will need to get a positive diagnosis of which fungus you need to treat.Â
Before you do go down that road, you may want to decide whether you want to be spending the time and money treating several times per year for multiple years- with sometimes less than terrific results, because the fungicides only prevent further loss.Â
If you are set on protecting the one tree that is not affected, it may be worth consulting an ISA-certified arborist to determine which fungus is affecting your trees. Find one in your area:
 https://www.treesaregood.org/findanarborist Again, this tree would need yearly fungicide treatments to protect the new growth from infestation.
Sometimes removing the most severely affected lower branches can improve the aesthetics of the trees. Choosing alternatives to spruce to plant in the future is also a good strategy.Â
Other practices to keep your spruce healthy:
- Improve Airflow: Increase spacing between trees to reduce humidity, which prevents fungal development.
- Watering: Avoid overhead irrigation; use soaker hoses at the base to keep needles dry.
- Sanitation: Prune out heavily infected, dead lower branches.
- Cleanup: Remove fallen needles from the ground, as they harbor spores that can re-infect the tree.
Read more about the disease and alternatives to spruce:
https://www.canr.msu.edu/news/what_is_spruce_decline_and_what_should_you_do_about_it
