Port Orford Cedar has white fungus looking growth climbing up the bottom of trunk

Asked January 4, 2020, 9:07 PM EST

I’ve seen a post from 2017 on this but no answer was given. The poster had paid $250 to an arborist who did t know what it was. The tree looks healthy but I’m worried about it. It’s also on the ground at the base of the tree. I included a photo of that too.

Washington County Oregon forestry trees and shrubs

6 Responses

The fungus on and around your tree is similar-looking to the one from a post in 2017. If you follow that thread to the final answer, the suggestion is to wait and see how the tree health is. Here is the post, "Port Oroford slime?" https://ask.extension.org/questions/436962
The forestry expert didn't think this was a root rot, but possibly a surface fungal issue. Information for the OSU Plant Clinic is offered for identification: https://bpp.oregonstate.edu/plant-clinic I don't know if the prior poster followed up on this.
As I did in 2017, I will forward your question to our forestry extension agent. Perhaps another expert recognizes the issue and can offer additional advice.

It is likely the fungus in the photo is not a "tree killer" pathogen, but rather a saprophytic fungus growing on dead material. I say this because you said the tree crown appears to be healthy and also the fungus is growing on surface material and forest floor litter. However, a definitive identification of the fungus would be needed to confirm this. The OSU Plant Clinic should be able to do this with samples of the fungal material and plant parts it is growing on. https://bpp.oregonstate.edu/plant-clinic

Also, I will send photos to some forest pathologists to see if they recognize this fungus and report back if I find any new information.

Thank you for the two responses. I had read the prior question and response which I referenced in my question. A wait and see how it affects the health of the tree, in my view, was not an answer since avoiding dealing with a sick and dying tree was the reason for the question in the first place. It is a very large tree and i did not want to be forced to have it taken down. I had an Ash tree taken down last year - it had some sort of root or heart disease/rot. Not that large of a tree and it cost $900. I also have another Port orford tree right next to the one with fungus and don't want two large diseased trees.

I was also thinking the fungus was not tree specific, as in a pathogen that attacked a specific living tree species, because the fungus was also on the ground. However, my concern was that it could be nonspecific and had spread from the ground up the tree. I don't know anything about fungus so I wasn't sure if that was possible.

Thank you both for your helpful responses. I have a next step which is helpful and I also hope you get responses from your additional inquiries.

I looked up the meaning of saprophytic fungus and it seems to go on dead material. Is tree bark considered dead material? Thank you.

Saprophyte: Saprophytes feed with decaying organic matter from dead organisms.

Read more: Difference Between Parasite and Saprophyte | Difference Between http://www.differencebetween.net/science/difference-between-parasite-and-saprophyte/#ixzz6BQSq4ofC

I sent the photos to our State Forest Pathologist and she said it was a fungus or perhaps a slime mold, and that she would would "describe it as a non-pathogen and not to worry about the tree’s health". So, the fungus/slime mold on your tree growing on forest floor litter and on dead bark outside of the tree is unlikely to be a problem.

The outer bark of the tree is dead material. The distinction between a saprophytic vs pathogenic is key. Many fungi only colonize dead material and are not pathogens - they don't make the tree sick. (Though a wood rot fungus can grow in the dead heartwood and cause structural failure of the main tree trunk resulting in tree death). Some fungi are both saprophytic and pathogenic, in which case you would find the fungus actually growing (infecting) the living cells of the tree.

The "wait and see approach was advised" because the tree appears healthy and there is does not seem to be a pathogen involved. As stated earlier, a definitive identification of the fungus/slime-mold would be required for 100% confidence.

Perfect! I am relieved. Thank you very much for going to such lengths to provide such a detailed answer.