Brown needles on interior of mature blue spruce

Question: 2 of my many mature blue spruces have very recently developed needles turning brown on some of the short mid height branches. They are not yet falling off with touch. They actually seem firmly connected. the trees are 20 years old and these 2 are about 20 ft apart. They are in a mulched area. Branches are not touching. There is a mature honey locust within 20’ also. This area of my lot is not exposed to wind or intense sun. I am in a subdivision next to the first foothill. I have about 20 blue spruces on my lot and they have all thrived. One time I had some needle rust on low branches of a different tree. I recall maybe treating it with a spray. It recovered well. please advise. shall I just remove the branches or should I spray with something? thank you

responder: Alison O'Connor, PhD  Replied November 08, 2024, 4:02 PM EST
response: Hello,  Thanks for your question. Would you be able to send me some additional photos? Specifically, one of the entire area below the tree and one where the trunk meets the ground, so I can look at planting depth.  What is below the tree? Mulch? Rock? Landscape fabric?  Does the other side of the tree have branches that look similar?  Thanks so much!

responder: The Question Asker Replied November 09, 2024, 6:04 PM EST
response: Thank you. Attached are some more photos. Yes there has been landscape fabric under the tree with a couple inches of mulch and certainly some needles have accumulated. The  fabric is 20 years ago and it has likely decomposed. There is some of the problem on the other side. But since most of it is interior it is not as noticeable. One of the trees is less dense and expansive with branches so it is much more noticeable (4th pic). Sent from Yahoo Mail for iPhoneOn Friday, November 8, 2024, 2:02 PM, Ask Extension wrote:

responder: Alison O'Connor, PhD  Replied November 12, 2024, 10:38 AM EST
response: Hi again,  I admit that I'm a bit stumped. My first thought is that it's a root issue because the damaged branches look a bit like they are spiraling. I also have concerns with the landscape fabric being placed below the tree when it was planted. It's likely that it's changed shapes, but I doubt that it's decomposed since it's made from fabric/fibers.   I do like that there is a slight root flare at the base of the tree, though it should be a little more pronounced, so I wonder if it was planted a little deep. Or if the root flare is now covered by soil/mulch. You could try to remove some of it to see if the root flare can be exposed a little more. In doing this, you might also look for any circling/girdling roots at the base of the tree. Circling roots often are below the soil surface but can compress against the trunk and cause various issues. They often show up years after planting and can be linked to compromised roots during the growing process.  If those branches are truly dead (no green tissue on the stems), then you can remove them. Otherwise consider leaving them until the spring to see if they push any growth.   You might also consider hiring a certified arborist to assess the tree(s) and see if they can detect anything that I'm missing from photos (very likely). You can find a certified arborist at http://www.treesaregood.com. If you're in Fort Collins, you can reference the list of arborists approved to do work in city limits: https://www.fcgov.com/forestry/arborists