tree spread

I was previously growing mahogany trees north of the maple and oak trees here, and a seed managed to grow here, where I can't cut down the tree. When it was growing, I just thought it was some kind of visual bug and ignored it. I'm mostly just annoyed because I can't get to the tree to chop it down.

tl;dr It takes a lot of repetitive work to keep the trees from growing out of control on my farm. I don't want to build three wide floors around them for two reasons; it doesn't match the rest of the farm and it blocks grass from growing. If the Gold Clock made it so trees only drop seeds one...