Asked June 18, 2015, 4:23 PM EDT
Hennepin County Minnesota
It's hard to tell for certain what is going on with your tree. It is normal for inner spruce needles to turn brown and drop in the fall when they have reached the end of their life cycle. Spruce needles can live up to 10 years. From your question, it sounds like the brown needles are still on your tree and the tree doesn't seem as vigorous as in other years so you need to look carefully and gather more information to solve this. There are two common diseases that can infect spruce: rhizosphaerea needle cast and cytospora canker of spruce. You can read about them here: Common Diseases of Blue Spruce
For more information on Missing or Chewed Needles on spruce, refer to the University of Minnesota's self-diagnostic site called "What's Wrong with My Plant?"
After reading the information on these sites and evaluating your tree closely, you may be able to diagnose whether you have a problem or not. If you have more questions, try submitting some good photos of the problem and your observations.
Thank you for contacting Extension.