I'd clean up the wound, being careful not to cut back past any live bark. If the tree is growing vigorously and the damage does not go much beyond what we see, it'll probably cover over the wound quick enough to recover.

Crabapples are non life threatening so no long term danger in seeing how she does. If the tree underperforms this summer I might revisit the idea of yanking it.

The total length goes about 18" long. Not sure how wide as I stopped remove bark.

How would you go about cleaning it up without cutting into live bark?

whaas,
With a wound that big on a fairly young plant I would probable ditch it. Too many crabapples around that can be had for a good price IMHO. Or maybe you decide you would like to go with something else.

Arktrees

I agree with Ark. I have a similar situation with a Harvest Gold crabapple that heals a wound then that callus dies and it heals again and then the callus dies again. As it stands, what started out as a small wound now takes up about half of the trunk circumference.

I recently scored a fairly good sized Merlot redbud for cheap as a replacement and planted it nearby the HG. I'm going to let the HG have one more year of flowering and fruiting then it's off to the burn pile. You might do the same if your tree is set to have a gangbusters flower year. Otherwise, chuck it!

I'm pissed that I didn't put a damn spiral wrap on this as I know Malus is susceptible to frost crack. This past winter has really tested my patience with gardening.

Need to figure out what to put in there for a short stout spreading tree. From a design perspective I need that shape.

Might just put the same thing in and protect it for as long as the spiral wrap will fit.

oh crikey ...

i would leave it alone for a year to see where it starts the healing process.. and then i would probably forget about it for another few years... and then i would trim it up ...

i would also keep it.. to learn from the process.. rather than yanking it out due to some predisposition to having everything perfect in my yard ... even visitors like to learn.. and you can point at such.. and explain the process .. [presuming of course.. you have real gardeners visit]

i can not imagine.. what made you do that to that tree .. other than.. as you note.. you were pissed ... maybe you should get rid of it ... its never going to stop pissing you off ... so be done with it ...

ken

First laugh of the day. I'd say what Ken said, but it wouldn't have been as funny.

If you are going to keep it, no harm in peeling off the dead bark (which is what my OCD self would do) . If and when it actually leafs out and starts adding caliper, it will be obvious where the live ends and the dead begins as well. Your yard is always so perfect, I'd recommend doing that replacement swap and maybe gifting this to a friend or moving it to the back yard.