I've always wrapped Aesculus from south facing winter sun when young. It appears to be a serious case of frost crack.

Frost cracks can be vicious, can't they?

There's a shopping plaza not far from me that has a row of some variety of columnar maple in a planting strip at the perimeter of the parking lot. Each has a matching trunk, just like yours, all on the south side. It's enough to make one think that student drivers on cell phones are responsible.

Where I grew up, we always painted the trunks of young, smooth barked deciduous trees, from the ground to the first set of branches. It's a practice that seems to have died with the old timers, but it had a purpose.

I could understand someone else's hesitation....to remove a tree like this....but you are Ken!
I'm shocked....that it's still standing in your yard....are you getting soft on us?

hey!!!

you can see how far it is from the house.. and on the opposite side from the house..

heck.. if i didnt have to mow the lawn.. i would never see the problem ...

ken

here it is in spring..
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What a crack and what a beauty!

Out in the middle of the yard I would keep it. Bet u have a hollow tree but hey, many end up that way. Just this one we know why.

Just to cause trouble: too bad we have no idea what tree neosporen to treat that wound with or else u could have prevented the rot.

Ken, you are full of interesting thoughts lately. Within a couple years it will have healed over completely and the two scabs will have grown together, leaving a small void in the center that will be less and less a factor relative to all the wood surrounding it when it comes to the strength of the tree. However, won't this violate your concerns about included bark? I suggest you create a small time capsule and insert it into the crack while you still can, then fill it with liquid nails so that you will have the tree nailed together in the center.

I'd leave it. The tree will never get big enough to fall on the house or anything it can really hurt. As to the future threat to the Mother-in-Law or others who are standing under the tree in an ice storm, heavy wet snow, tornado, etc., that would just be the Darwin Principle at work and they would be a minor Darwin award winner for not coming in the house under nasty conditions. I think you can beat the premeditated murder wrap that you planted the tree, let it sunscald, left the tree for 20 years to get massive, knowing your Mother-in-Law would stand out under the tree in a tornado. I bet Pinocchio could get you off charges like that!