hole in the base the Chinese elm

[Gaston]

Hello friends, I want to know if it is possible to close the hole in a way. Thank you

 

[Gaston]

Up

 

[bonsaidave]

I don't think that split will ever look right/good.
GroundLayer that sucker just above the split.
That's my vote.

 

[JosephCooper]

Bury it below the hole.

 

[MrFancyPlants]

I think air-layer up, even higher, near the branches and make a sweet shohin out of it.

 

[Cadillactaste]

You won't be able to fill it. An air layer above it would be an option if it bothers you. That would be the only option I could see.