I've got this small tree growing along the ditch line that I'm thinking might work for a Hokidachi bonsai with a little coaxing. I was thinking about chopping all the branches back and air layering the trunk below the branches. I would think, within a couple off months, I would then be able to remove this and pot it where it can be allowed to grow more before starting to train it down the road. Below are a couple of pictures of the tree in question. Does this look like a Broom style candidate to anyone else besides me?