Brown sap leaking from a dead branch stub on the Elm tree

[proninyaroslav]

In autumn, after pruning trees, I usually leave small stubs and remove them in summer. Today, at the very top of the Elm tree, I noticed this strange thing.
Some brown sap leakes from the ends of two dead stubs, and this sap stains the hands, it has no smell.
I immediately removed these two stubs (the other stubs look fine), cut them down to living tissue, and dusted them with a copper-containing fungicide powder.
Living tissues looks normal, the tree looks healthy overall. What is this? How dangerous is this and what to do next?

 

[Tieball]

I’ve not see that sap yet, especially from dead branch stubs, however, all of my elms are American Elms. Different. So I don’t have good advice. Your overall leaves look healthy though. Someone will step in soon though with some experience.

 

[TomB]

I find elms often leak sap after pruning. If it rains, you’ll find it becomes a thicker gel.

 

[proninyaroslav]

I find elms often leak sap after pruning. If it rains, you’ll find it becomes a thicker gel.

Well, I've seen this on root cuts, but these stubs were cut off last fall and dried up a long time ago. Unless such can be?

 

[rockm]

Looks like you may have applied some kind of sealant on one end? Can't really tell.

Could be anything, but probably nothing of any consequence.

 

[proninyaroslav]

Looks like you may have applied some kind of sealant on one end?

No, I did not apply sealant, it wintered with these stubs as is. And just today I treated them with fungicide after I saw this strange thing.

 

[Gabler]

No, I did not apply sealant, it wintered with these stubs as is. And just today I treated them with fungicide after I saw this strange thing.

Well, cut off the stubs, sterilize your tools between cuts, and seal off the wounds. That’s what I would do.

 

[rockm]

No, I did not apply sealant, it wintered with these stubs as is. And just today I treated them with fungicide after I saw this strange thing.

Still, could be anything. --my bet is bark tannins. Tissue around the edges of the piece look green and healthy...

 

[GGB]

If it's a chinese elm that's just what they do, especially after it rains. They exude a thick jelly. No need to seal the wounds

 

[proninyaroslav]

Tissue around the edges of the piece look green and healthy...

Yes, I cut a little below the dead part down to the live tissue to make sure nothing was left there.

If it's a chinese elm that's just what they do, especially after it rains

No, it's a common Elm. And this cut was made in the fall, and these stubs have a few millimeters diedback over winter.

 

[GGB]

ahh never worked with them, only know chinese (parvifolia)

 

[Tieball]

The leaves and growth remind me a lot of Zelkova which is in the elm family.

 

[proninyaroslav]

The leaves and growth remind me a lot of Zelkova which is in the elm family.

In the spring it has such leaves, but they become normal, as Elm should be. As far as I know we don't have Zelkova. Its spring buds look like Chinese Elm (Parvifolia) buds, while in Zelkova they have a pointed shape.