In my neighborhood, lots of spruces are showing signs of spider mites - or maybe something worse. There are so many trees afflicted that I can't believe there could be that many spider mites doing that much damage! But I don't know a lot about these things. I've pretty much lost one small tree to the mites - tried the blasting with a hose (almost) daily, but they won. I've attached pictures of a tree in my yard where a hose won't reach, and I think it would have to be a firehouse to be effective. Is there any other treatment, like a spray or something to put in the soil that might give this tree a chance? Thanks.
Blue spruce is not native to our area and often has difficulties over time in Maryland.
There are significant disease issues that occur, often in conjunction with stress issues like drought.
Here is a page about the most common disease issue, Cytospora canker: https://extension.umd.edu/hgic/cytospora-canker-spruce
In addition, here is a related article by our plant pathologist.
Unfortunately, there is not much that can be done.