Question about a weird fungus I found on my Japanese maple last week

Last week in my Portland backyard, I spotted a bright orange, jelly-like growth on the trunk of my favorite Japanese maple, and after checking my old plant pathology book, I'm pretty sure it's cedar-apple rust, which can spread to other trees if not handled. Has anyone else dealt with this specific fungus and know the best way to remove it without harming the tree?

4 comments

4 Comments

henry_murray2mo ago

I just cut the infected branch off with clean pruners and bagged it for the trash. The tree sealed the wound fine and didn't spread to my apple trees. Keeping things dry with better airflow seemed to help it from coming back.

harris.andrew2mo ago

Keeping things dry" - did you change how you water the tree, or was it just the weather?

jason_stone592mo ago

Honestly, that rust looks worse than it is, my maple had it last year and it's fine now.

ward.anna4d agoTop Commenter

Just a heads up, that bright orange jelly stuff might actually be something called witch's butter (Tremella mesenterica) and not cedar-apple rust at all. It usually pops up after wet weather and feeds on dead wood, so if there's a little rot spot in the bark it's not hurting the tree, just hanging out.