Hi - about 3 weeks ago I noticed several browning branches on my spruce that has otherwise had new growth (Even this spring) and previously appeared healthy. The branches losing needles and appearing to die has quickly spread up the tree. Also there are several large resin patches. It’s sister tree also has the resin globs but no dying branches yet. I removed one of the resin patches and found a worm boring into the tree. What is happening? Is there anything I can do to save my tree? Will it spread? I have 2 more mature healthy spruce in my front yard, thank you for any info you can offer.
Macomb County Michigan
The globs with oozing sap are cankers. These symptoms are caused by fungi that infect branches or stems on the trees. As the fungus interferes with water and nutrient transport, this would be the cause of the browning branches and decline. Page 3 of this document describes cankers in a bit more detail: https://web.extension.illinois.edu/plantclinic/downloads/Plant%20Clinic%20Report%20Spruce.pdf
From your photo, it appears the upper 1/3 - 2/3 of the tree is in moderate to severe decline. As there are multiple cankers on the tree, the odds of this tree thriving are not good. If you wish to save the tree, I would advise pruning out the affected areas, keeping it well-watered, and fertilizing in the fall.