When we had Robert Porch over speaking at the club last year, he was talking about how a lot of the small maples we see from Japan are air layers developed on a parent plant and then layered off. One of the techniques that is used is to ring the tree with wire at the point where you eventually want to layer. Then while you develope the tight branch structure the wire bites in and causes the trunk to swell at this point. Then when you are ready to layer you already have a wider nebari to work with.
I’ve been meaning to do this all year on a maple in my garden but only got around to it a few weeks ago. Late in the season, but maples tend to bulk up in the autumn and I intend to leave the wire on through next year and layer off in 2015. I’ll keep you posted as to how this works for me. In the meantime here are a few of the bits I’m layering off. Some better than others but I want to do as many as possible on the same tree.