Is it possible for this wound to completely heal?

[The Warm Canuck]

I just cut back a buckthorn that I collected last year, I had to go real low to find live cambium on both sides. I'm planning on putting this back in the ground. Is it even possible for a wound like this to heal? Or should I be thinking of cutting a split trunk into it.?

 

[Gabler]

I'd let it go, and either it will heal or it will split on its own as it decomposes.

 

[Shibui]

It is possible for a wound that large to heal. The question is how long will it take?
More growth above the wound = quicker cambium growth and therefore quicker closure. The problem is we are usually moving into branch development and building ramification at this stage which usually requires containing growth somewhat with a smaller container and regular pruning so healing wounds takes longer.
Bark can only grow over sound wood. If the wood begins to rot before the bark grows over, it becomes more difficult. I've been treating the exposed wood with lime sulphur to extend the time it will remain sound. It is also possible to carve out rotted wood and fill with something like epoxy. New wood will happily grow over an artificial surface.

The other option is to allow the wood to rot and carve out a hollow to form the split trunk you mention.

I don't think either is better or worse. Just 2 different possible future trees.

 

[Animron]

Maples, elms, oaks, beeches and even some pines would heal such a wound in a few years if you let their tops grow freely (and preferably let them grow in larger containers or in the ground). But for trees (shrubs) like buckthorn and hawthorn I'm not entirely sure that this can be achieved in the short term.