Since fir trees are rarely grown in Maryland (save for a few Christmas tree farms), we have limited information on the various pests or diseases that may be responsible for dieback, but it would help to have photos. You should be able to use the "choose them" link in the question submission platform to select image files from a computer or phone. Or, you can try pasting the images directly into the body of your reply. Another option is to upload the images to a shared photo site (like Google Photos, Flickr, etc., if you have an account with any of them) and send us a link to view them.

While fir trees can be susceptible to various fungal needle cast diseases, whole-branch dieback or browning sounds like something else, possibly even just damage due to the ongoing drought unless you've been periodically watering them. Botryosphaeria canker, as one example, is an opportunistic fungus that infects branches on shrubs and trees stressed by environmental conditions like high heat and drought. (Deer browsing damage would be missing foliage, not browning needles or dead branches unless antler rubbing stripped the bark from the lower trunk.)

Miri





Thank you! I am very familiar with Swiss needle cast in Douglas firs

and that's not what's going on here. Please see the pictures.

On Apr 17, 2026, at 12:43 PM, Ask Extension wrote:



Thank you for the photos, they are very helpful.

The damage pictured looks just like "buck rub," which would have been from deer antler rubbing killing the cambium tissue under the bark, but if some of those instances are too high on the tree, then perhaps it's squirrel damage, as they will remove bark to add to nests (or perhaps to eat the nutrient-enriched tissues in the cambium). Porcupines favor eating the inner bark of conifers and some other trees in much the same way, but we think they would probably be less likely to be a problem in a suburban setting. (They've been observed in Carroll County but not Baltimore County, though it's always possible they're around and unseen.)

It's hard to see the bark injury clearly, but it doesn't look like cicada damage, nor would that be a typical symptom of cicada egg-laying injury. Periodical cicada damage was done five years ago and would not be causing dieback this long afterwards, and annual cicadas tend not to cause such noticeable damage or dieback (if they even use fir trees at all as an egg-laying site). Fungal canker diseases can cause cracking and bark splitting, but not in the way that looks shredded as it was removed as some of the pictures suggest.

For now, the cause (since we agree it doesn't look like needle cast disease) may not matter since there's no remedy other than to prune off the affected branches since they can't recover. If you haven't already been doing so, alleviate drought stress on the trees with occasional watering, since much of the state has been in drought status for most of the past two years and it's stressing many plants, either directly causing dieback or predisposing them to secondary pest and disease issues that opportunistically take advantage of stressed plants.

Miri



We can't tell from the added photos what the cause of dieback is, but all you can do is prune off any all-brown or bare branches since they won't regrow foliage.

You're welcome.