Looks like the trunk split issue common with a lot of Freeman maples, which Armstrong actually is (red x silver hybrid).

Sometimes they recover, sometimes they don't. If there is a warranty/guarantee on that tree, I'd take advantage of it if I could.

its a function of a very large transplant.. along with winter sunscald... and perhaps improper deep watering...

excersize your warranty ... as per above ...

how about a pic of the whole.. info on how planted.. by whom... and watering protocol afterwards...

ken

ps: is the damage on the south side.. perhaps SW>??

Bet it's planted too deep. Could be the other problems listed above, but when you said "installed", 80%+ of them have no real clue as to what they are doing. Usually some minimum wage person, that was told (go plant that tree). That or a "monkey with a shovel" that claims to be a "professional landscaper" and knows basically nothing, except to charge you for every little thing, and how to blame someone else.

All the above is JMHO.

How about a picture or two of the base of the tree.

Arktrees

Thanks. This was planted by a local nursery. I don't remember the exact watering instructions but I don't remember any long lengths.

The nursery saw the pic and said it was damaged by something and no disease could have done that. Warranty doesn't cover damage.

The nursery recommended getting a tree wrap and wrapping it loosely until August to keep insects out. They said it should start healing.

The damaged area faces north.

hmm, i have same thing on a weeping cherry, its doing decent but te tree is old and has fungus growing on it too, an apple of mine has similar but 100x smalle wounds, only 1 inch wide and long, facing southish, so far no problems from either tree, but they arent maples , and your damage is worse

This is sunscald damage which is not uncommon among young, thin barked trees, particularly maples. I would replace this tree. Young trees with major sunscald damage generally do not reach a mature height before breaking off. Wrap is effective after first planting, but will not serve any purpose now.

If the nursery says this is "mechanical damage," choose a different nursery for your next tree purchase and installation.