Disease id

I found this on a couple of branches of a small 2" diameter trunk tree growing in a corner of our backyard. I suspect it could be a decorative cherry/plum seedling but uncertain. Any idea what it could be and what % certain you are about it?

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Black knot


Thanks. My question was a bit vague…, can you say what % sure you think it’s black knot?


Not an expert on black knot but i do agree that looks very likely to be it.

I have had a couple spots of black knot show up on one of my eu plums… i found both at season end after leaves dropped. Did not notice it at all during the summer or fall… but once leaves were off it was obvious.

I removed an entire limb this time… hoping to be rid of it.

Good luck.

Ps there are lots of black knot images online and common issue is the branch affected swells like yours is…

Black knot

you can try on “garden professor blog” on FB, for professional opinion. Remove 6 to 8inch below knot. And check in your area if you see a lot of tree infected with black knot. A good pruning can help. Disinfected your blade after pruning.

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