This Chinese Elm came into my care last year. It had been doing well for a few years and then it had a major bad episode and lost all the bottom branches. All that was left was a nice base, a long straight bit then a few branches at the top. I repotted it out of the original poor soil. After a few months it had leafed out again but was never going to make a convincing tree without lower branches. I spoke to the owner and suggested air layering the top off it and then creating a better tree from the base. Fair play to him, he agreed. I left the layering until March this year and a few weeks back I checked the progress.
Signs of decent roots in the layer.