My vote is for it was wounded during transport or from some pruning cuts and its just showing up now. Assuming these are like our native Sycamores....these grow fast around here. How are you watering it? I'm not sure they're the easiest trees to over water.... I think you have two choices, neither of them are great unfortunately. 1. cut out the rot and see if the tree encapsulates it, I'm not excited about this if anything is near by in a potential 100 foot tall tree in my area anyways. 2. train up a sucker from below the wound and let it become the new tree.

It sounds like canker, and cherry trees are very succeptible. If it's in the trunk , there is no cure. On an outer branch, you can cut it off and hope. UC Davis says prevention is your only choice, by choosing resistant rootstocks and avoiding bark injury when it's cold and wet. Carla in Sac

dont worry about it ... do you mean you moved house??? ... do you plan on planting it in mother earth??? think about it this way ... when its 5 or 10 years old ... that whole part of the trunk.. would probably be bare ... so no need to worry about it now ... [though it will be hard to grow it in a pot that long] ... and i note.. the terminal bud survived ... so onwards and upwards from here ... dont love it to death ... imo.. it will take care of itself ... ken ps: i dont get the string or what not.. in the first pic

Hi there, Stax. Thanks so much for assuming I didn’t have a conversation with my own child. What a dumb comment to make. Last time I checked this wasn’t a parenting app? The point of the post was this: I know nothing about trees, especially River birch trees, some kids thought it would be fun to peel lots of bark off...does it look okay, in your experience, or should I maybe take action (I.e, wrap the tree, have someone come out and look at it). The only thing I know about tree bark it functions like somewhat like “skin” and is what provides nutrients to the tree and that a tree can be girdled or die from de barking. Simple as that. As far as I’m concerned how I handle the situation is my business only. I only explained what happened so that anyone who reads this post had context as to how the damage occurred. As for parenting, at the of the day all children should be taught by their guardians to respect other people’s property 🤷🏼‍♀️