Hi, Just noticed this growth on our Dolgo crabapple. It’s about head high, and 3-4” long and wide. Fungus? Just something cool? Or sign of disease we should address? The Dolgo is generally very healthy and happy for the last 40 years. It has, of course, been an absurdly wet year. Thanks!
Forty years is pretty old for an ornamental fruit tree.
This is a fungus. It looks like it may be what is called a 'tooth fungi", which is not mature yet. They are cool, but it is a type of wood decay fungus- meaning it grows on decaying/wet wood.
We can't see, but it may be growing on an area where a branch was removed previously and the tree wasn't able to heal over and compartmentalize the wound.
It also looks like there is some sloughing bark and borer holes, which is not a good sign.
There is not any treatment we'd suggest, other than supplemental water when we enter periods of drought. It could take years for serious decline, which would likely happen slowly. Enjoy your beautiful tree as long as you can.
Thanks! Good to know re: the tooth fungi.
Holes are actually woodpecker (hard to tell from the photo). And I would protest - Dolgos go beyond ornamental...one of the few crabapples that make great pie, jam, and jelly! ;)