mushrooms growing on silver maple

Question: I had a good size mushroom like growth on a previously cut stump on my mature silver maple. I scraped off the growth but noticed there is a hole into the limb under it. I doused with vinegar and water. I am concerned that there has been damage to the limb that might spread to the rest of the tree. Suggestions? Do you have someone you recommend that could look at it?

responder: An Ask Extension Expert Replied June 14, 2024, 10:00 AM EDT
response: Thanks so much for reaching out! Can you send a couple pictures of the entire tree? I cannot help with the mushroom identification (you can reach out to Denver Botanic Gardens) It looks like some decay is happening within the tree - if you send me a picture of the whole tree that will help me determine whether it has spread or not! Thanks so much, Rachel Durkan

responder: The Question Asker Replied June 14, 2024, 1:53 PM EDT
response: Thank you for your help. I really want to address this before it destroys the tree.  On Jun 14, 2024, at 8:00 AM, Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied June 14, 2024, 2:53 PM EDT
response: WAY higher than I though! Can you tell how deep into the tree the decay goes? Trees have this amazing way of healing themselves called CODIT - compartmentalization of decay in trees. When a tree has a would or a limb cut off it will stop sending nutrients to the limb and block it off so the rest of the tree doesn't get sick. I always compare it to a ship with a water leak - there are different doors the ship puts down to prevent the water from getting into the rest of the ship. Same idea for trees! Here is more information to read about it if interested. It is very cool! Why that is important is because if the tree has quarantined that part of the tree off where the mushrooms are growing then it should not affect the rest of the tree. The mushrooms are probably just breaking down that stump that is leftover from the cut on the tree. If you look in there and see that it is going deeper into the tree and into the live part of that branch than that may be an issue - but the tree will work to save the limb.  Hopefully that is helpful! Rachel

responder: The Question Asker Replied June 17, 2024, 2:32 PM EDT
response: We put a dowel down into the cavity. You can see from the attached photos the direction of the hole. At its deepest point, it went in about 13" (7" appears to be wet). The decay/hole appears to go straight down, and does not appear to extend in any other direction. The opening appears to be about 3" in diameter. The hole is too small to get a photo inside. The limb (at that point) is about 14" in diameter.  What are your thoughts on the next steps (if any) that I should take? Thanks for your help. Chris Marranzino  On Jun 14, 2024, at 12:53 PM, Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied June 19, 2024, 4:17 PM EDT
response: I would have a certified arborist come take a look at it to see whether they recommend removing it or not. Because of where that limb is on the tree and how large it is I would be extra cautious with getting it looked at. Silver maples are known for having weaker wood so always better to be safe and get it checked out! If you do not have a tree company that you already use you can use https://www.treesaregood.org/findanarborist to find an ISA certified arborist in your area.  Thanks for reaching out!Rachel

responder: The Question Asker Replied July 22, 2024, 7:20 PM EDT
response: Thank you for your help.   I have consulted 4 arborists. Several have recommended the use of a product called Cambistat to slow growth of the maple tree and help as a fungicide. I don’t find any information about this product on your website. Do you have any information or recommendations regarding Cambistat?   Thanks, Chris Marranzino   From: ask=<personal data hidden> <ask=<personal data hidden>> On Behalf Of Ask ExtensionSent: Wednesday, June 19, 2024 2:17 PMTo: Chris Marranzino <<personal data hidden>>Subject: Re: mushrooms growing on silver maple (#0142228)

responder: An Ask Extension Expert Replied July 25, 2024, 10:58 AM EDT
response: Good morning! I have not heard of that used before but I reached out to my colleagues and found some information for you! It has been shown to increase a trees resistance to fungal infection or bacterial decay. It can also decrease shoot growth which could lower risk of failure for a tree with decay issues. It can slow the growth of a fungi and cause thicker cell walls in new growth in the tree which could be harder for some fungi to penetrate.  Here is an article that reviews the product a little bit - Growth Retardants: A Promising toll for Managing Urban Trees  I have also attached another review of the product from 2021 that was shared with me.  Thanks!Rachel