How do I heal these chops?

[Scrogdor]

Wondering how/if I can fix this area to heal over and become part of the base? It’s a Korean Hornbeam.

I didn’t want to cut the area out because there are roots growing from the tips.

 

[Bonsai Nut]

You heal those scars by thickening the trunk. You thicken the trunk by creating more vascular demand by the tree. In other words, let the top of the tree grow, and it will trigger root and trunk development. It is almost impossible to get trunk scars to heal without letting the tree thicken.

 

[Shibui]

More growth above heals cuts.
I not you've left a shoot growing beside one of the cuts. Common misconception that an adjacent shoot will help heal a cut. My experience is that the branch will close the cut quicker but after you remove it what have you got?
Another cut to heal and usually it's almost the same size as the one you've just healed so you are then back to square 1 with the extra complication of adjacent scar tissue.
Using adjacent shoots to heal cuts appears to be another bonsai myth so I don't use it now.

 

[misfit11]

You can take a sharp knife (like a grafting knife) and gently re-injure the sides of the wound. Just scrape the very edges and expose the cambium underneath the bark. Then seal it with cut paste. This will stimulate the tree to callous over the wound.

 

[Scrogdor]

You heal those scars by thickening the trunk. You thicken the trunk by creating more vascular demand by the tree. In other words, let the top of the tree grow, and it will trigger root and trunk development. It is almost impossible to get trunk scars to heal without letting the tree thicken.

These were all nubs when I got the tree, used a knob cutter to get them flush with the base. This is a long project so should be no problem letting them bark over then. Still have 2-3 sections of trunk to grow out . Thanks

 

[rockm]

FWIW, allowing the tree above the wound to grow uninterrupted is the faster way to close pruning wounds. Also FWIW, Korean hornbeam is notorious for healing big chops very s-l-o-w-l-y.