Acer fungus??

Pisa3456

Hello all,

This fungus is growing on my Acer. Any suggestions as how to kill it off?  It is a very old tree and have had to cut a third of dead wood off over the years.  Will be sad to have to finally let it go.  

Thanks,
Anthony

BobTheGardener

Fungus generally only grows on already dead wood so it is appearing because the tree already has dead sections and is not what is causing the tree to die.  You have 3 choices really:

• cut out all dead wood to a point where the wood looks healthy; risky because acers hate pruning.
  
• leave it as it is - it may yet continue living for several years.
• remove and replace.

If it were mine, I'd go with the 2nd choice but would tidy up those savage looking cuts.  If removing a whole branch, you need to cut it off close to the trunk and not leave a stub as those will nearly always die and are then prone to disease.  This may have been what enabled to fungus to take hold.

The good news is that the fungus is only growing in the dead heartwood of the tree and the living part of the tree (which is just beneath the bark and known as the cambium) is of no interest to the fungus so it will carry on growing until so much heartwood has rotted that the tree falls.  Even that could be decades away as every year the cambium lays a new layer of heartwood (xylem) underneath itself so you could end up with a completely hollow but living tree.  I'm sure you've seen ancient oak trees like that?

Pisa3456

Hello Bob, 

Many thanks for the in-depth feedback.  I’m not familiar with gardening so every suggestion helps.  I’ll endeavour to trim those stumps.  Should I also cover the open cuts with something like thick paint or varnish?

Thanks,
Anthony

BobTheGardener

Hi Anthony, the RHS now recommend leaving cut surfaces alone as it seems to promote faster healing.  Use a sharp saw to try and make all cuts smooth with no jagged edges.  If you need to remove large branches, follow the tree pruning advice here:
http://statebystategardening.com/state.php/wi/newsletter-stories/make_the_right_cut_when_pruning_trees/
I hope it makes it - looks like a lovely old tree apart from the damage.

Skandi

And I'm pretty sure that's the fungus you find in those mixed bags of frozen stirfry. renamed to "Wood ear" recently It likes elder best but I have it on elm here as well. I've only ever found it on dead and generally long dead wood so I agree that it's probably not doing your tree any harm at all.

Pisa3456

Many thanks to you both for the feedback.  Greatly appreciated!