Mt desire is to air layer the Hanoki Cypress pictured below just below the trunk division. The tree is now in an energy positive state. However, understanding from the live streams that if the process is going to take more than 90 days there must be a branch below the air layer to support continual root growth.
As there will be no branch below the air layer is this Hanoki a suitable candidate?
I would also like to know if hinoki need a lower branch to air layer. While I have rooted several cuttings with great success, my gut tells me a hinoki will need a lower branch.
I take it you are concerned with the inverse taper at the junction. If you cannot air layer this tree you could consider jining the smaller trunk and spreading the foliage of the larger trunk out a bit.
If in doubt, you could try girdleing the trunk with thick wire and bringing the soil level up. As the trunk thickens, the theory is that it will throw roots above the girdle