I read a post that Al had commented on about pruning one side of the slingshot off a tree to help with trunk taper. I received this in the mail in March, it had already started to leaf out. My long term goal is to keep it in a pot indefinitely. If it turns into a bonsai experiment so be it. If it's recommended to let it grow for this year before the trunk work I can do that too.

I think I'm wanting to take the left side off and am looking for people's opinions on that. My main question is which time of year, mid summer or late winter would be the best time to do so?

Thanks for looking !