AusBonsai

Has anyone got any tips on how to stop bark die back on my Chinese elm? It been happening on only one of the trunks for at least a few years. Not sure what to do.
I'm thinking I should repot and root prune into a more open mix and keep in full sun. Not sure if I should treat for fungus and with what.
Thanks!

It is difficult to tell without a photo of the whole tree, but from what I can see it looks like the "die back" has ceased. It might be time for a redesign?

I also think it looks like the edges are healed up so dieback has well and truly ceased. Often the dead area is hidden under the old bark and though the dead section is not getting bigger the bark slowly peels back to show the real extent of the injury so it appears to be getting worse but only showing the full extent of the original damage.
Fungus is unlikely to be the cause and it does not look like it goes right to the ground so root problem is not likely either. We can't see the top but this sort of damage is often the result of damage to a larger branch, sunburn or physical damage to the trunk.
If you are in any doubt about the quality of the potting mix or how root bound the tree may be I would always repot. At least then you know when it was last repotted, the state of the roots and of the potting mix it is in. Repotting does not hurt trees. It usually gives them a boost.

Thanks so much for the advice Watto and Shibui.
The strip of brown bark between the dead and green bark seems like it's a bit soft. I was thinking that this was the area that is progressively dieing and continues down the trunk. I've also noticed alot of random branch and sub-branch dieback.

Having said that, today I repotted and it was very root bound. So perhaps that has been the cause. I pruned the roots and hosed out all the old soil and potted into a wider pot with more open mix. I forgot to get a pic of finished product. Will add a pic tomorrow.

Root bound pic
[image]https://drive.google.com/file/d/1bgsR3u ... p=drivesdk[/image]