The primary branches on this tree were made by thread-grafting, and the tree itself was made from an air-layer of nursery stock I bought in 2008. So this tree is pretty artificially developed. However, to keep growth dense and movement present with trees, sometimes this is the only way to go. So long as the result is convincing, the means don’t matter.
The trouble with this tree is that the left trunk has a long span with no branches on the right side. In time, the right trunk sill fill in the lower part of the space, but the left trunk does need a branch somewhere along this span:
Ideally it will be between two left branches, creating an alternating branch pattern…somewhere around the blue circle, on the outside of a bend:
I spent a couple years growing out a long branch to use for a thread graft. The right time to perform this work is just before buds swell in late winter.
First, I verified the shoot would make the bend into the spot I planned to thread graft. Check.
Drill the hole in the opposite direction the graft will be threaded. The exit side tends to be messy, while the starting point tends to be cleaner; and it is important to have intact cambium close to the graft.
Thread the shoot through the hole, careful to not knock off buds going through, and orienting the buds so they emerge close to the trunk. This will allow options and keep bifurcation close to the trunk, rather than starting a branch on a long internode.
Here, 3 buds (circled) and a 4th internode (squared) were threaded through. Notice how close the first bud is to the trunk?
Next, cut a small branch to use as a wedge to secure the graft tightly to the edge of the hole, and seal up both sides with cut paste.