This is a dwarf Acer Palmatum with very small leaves that is suitable for training in a broom style. However it is a grafted tree and has a nasty inverted taper at the graft union. It has survived untouched in a pot for years. I have never tried any form of air layering so I thought I would have a go as I have nothing to lose.
The ugly inverted taper
Bark removed and rooting hormone applied
Inverted plastic pot cut to fit around the trunk and packed with spagnum moss. Its wait and see.
It’s a pathetic looking specimen but I have only done this to see if I can.