Advice needed - English elm with large, deep trunk wound

I am looking for some advice and guidance on what to do with this English elm (Ulmus procera) that I acquired earlier this year. I could use some suggestions on how to handle this tree with a very large wound on the trunk.

My concerns

  • The wound has created a rather unsightly nob fairly low on the trunk. I think this could be addressed by establishing a new front and changing the planting angle. In all likelihood it’ll probably get worse over time.
  • The wound is quite large. You’ll see in the pictures below - not only does this go high up the trunk but I’ve discovered that it is also quite deep. I’m concerned about how deep into the trunk the soft wood goes and how much more I’ll need to dig to get to something firm.

Possible solutions

  • Air layer above the wound. I rather like the current height of the tree - but I’m also concerned that this wound will fester and grow worse over time and jeapordize the health of the tree. I feel that I could air layer above the wound and do it cleanly or I could try near the top - possibly use that to establish some interesting nebari.

  • Clean and fill. You’ll see in the pictures below that I started digging into the wound today to remove the rotting wood inside. It went a lot deeper than I was expecting and I still have futher to go. My plan here would be to completely clean the area and fill with a manmade epoxy. The begin the multi year journey of repeatedly opening the callous to get this to close.

About this tree

  • Purchased this from the owner who said he had grown this from seed about 25 years ago
  • Could have been repotted this season. I always move slowly on newly acquired trees until I understand their current situation - after removing the top soil it seems clear to me this tree is likely rootbound and was in need of a repot.
  • Otherwise this tree is in good health. Good amount of new foliage this spring, no signs of weakness.

What do you think?


Not sure which way previous owner intended the front to be


Opposite side showing the numerous trunk wounds


The wound before I started to dig in


Removing some of the material


Very soft, easily removed, cork-like wood

I love your English elm. Good purchase #1.
I really think the wound gives it character that I like. So I wouldn’t worry as much about that. The problem for me is the reverse tapper on one of the higher branches. Maybe you have already come to a soulution for that.
#2 I think doing a air layer at the wound sight to keep the thickness of the trunk would be really nice. Not sure if that’s possible without major die back. Messing with the water column seems risky, but if you could accomplish it. It would create a interesting design and accomplish a technique that is unique.

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Yes for air layer as it has inverse taper otherwise.
Looking on the second picture and considering the left side branch has few swelling points and is quite thick anyway have you thought of getting rid of it and create a raft? The right side one has many beautiful branches growing same direction. Long term project but it has great trunk shape for that.
Amazing material I have to say!

Hi @JadedEvan
I think the feature gives the tree character and movement. I would probably dig out the rot, put it in a bigger pot for a few years, feed it and let it grow to heal or enhance the feature. If you decide to air lay, elm responds well.

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In one of the videos in the library, Ryan says that with a very large wound like that, the dead area gets too moist and the callus won’t roll over that. He showed how to dig out the rotten wet pithy stuff, and filled it with some kind of hard substrate (epoxy, cement?) and then re-wound the edge, which he said would enable the callus to continue to roll over the area.