Black Sooty Mold? Black Rot? Other? Apple/Malus Bark

I apologize for having waited until December to photograph one of two apples of (4) total I think I have planted. When I first saw this it was a sooty fungus that appeared to be 1/8"/ 2-3 mm of spongy-looking & sooty-looking and very black in color. Now it looks dusty to me and gray, & definitely non-spongy.

I found this photo and this is precisely what I’m talking about but disagree with the website’s diagnosis, but please set right if this is indeed black rot:

Here’s the `website to that photo.

Thanks for helping me go about fixing this. As far as unaffected tissue beneath this possibly 12" distance of fungal “something” I may have a couple inches before I’m at the graft union.
All the branches above the assumable problem area are perfectly fine. There are many branches.

I don’t know the rootstock.



Love to see a good answer as I see the exact same thing on my Apples and would like to know myself.

I’m anxious to see the answers as well. I’ve got a number of apple trees with this exact issue. I’ve always referred to it as black soot, but have no idea if that’s what it is…and I have no idea how detrimental it is or how to make it go away.

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I had that same issue for the first time last year on just one of my apple trees. Kept thinking fireblight? It worried me but I left the entire branch on the tree. No sign of getting worse, spreading or canker eruption.

Later in the season a friend who grows apples nearby sent me a photo of apple tree in his orchard with same issue. He decided to prune out the branch just in case it would spread.

I finally had to assume it must be black rot as I have been getting more and more summer rot issues the past few years despite spraying Captan every 14 days. Maybe not but that was my conclusion/guess.


Dax, It is a ‘rot’ for sure. Was the area injured, or did the bark spontaneously die in those vertical strips?
The second photo shown is black rot. There is also ‘white rot’ or bot rot which I think can be more virulent, and thats what your 1st pic looks like. It will manifest as exfoliating patches on bark surface, and then next year cambium dieback and callusing of surrounding perimeter. Supposedly a sign of stress…and not much for preventative(irrigation or other stress relief measures?) curative measures besides pruning out and sanitation that Ive found. It seems like theres more weird stuff effecting apple trees lately!


Being rural that tree and a lot of my trees are eaten and mashed into by deer. It’s windy and that tree is leaning from wind - so I expect it was rubbed inside that cage quite aggressively.

Thank you for your answers, Jesse.


I have a red gravenstein that was chopped for shipping, and I didn’t trim it back to the crotch when I should have. It bled like crazy for a couple of years (in the spring I think), and is black, but it hasn’t affected the fruit or any other portion of the tree. This is how it looks today.

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