I have seen this done. They started with a wooden cone, and attached the seedlings onto the wooden cone with small nails. The nails got covered over as the trunks fused. They also didn’t run all the trunks all the way up. Since the base was bigger around than the top, they let some of the apexes of the seedlings grow out horizontal to become limbs. It still had problems. Since the cone was there, the taper was very uniform. Some seedlings grew faster than others, so there were vertical bulges all around the trunk. Not all the seedlings fused together at the same rate, so it was still very apparent what was happening: artificial looking. And worst of all, trident seedlings are all different genetically, so the leaves coming from each one varied a little from the others. Different sizes, shapes, colors, etc. It looked very much like a “Frankentree”.
So, to have better success at the style I saw, I think it’s good to have an underlying frame, just not a perfect cone. Use rooted cuttings from a donor tree so that the grow rate and leave quality will be consistent. Nailing the trunks to the frame is ok, but some method of binding would help, too. But, the binding needs to be removed and replaced fairly often to prevent scarring. Bending out some apexes to be branches is a good idea, just need to not bind them.
All that said, it’s STILL probably better to do the traditional ”let grow and cut back” method. You’ll get better taper and a more natural looking trunk.
Good luck with your projects.
So, to have better success at the style I saw, I think it’s good to have an underlying frame, just not a perfect cone. Use rooted cuttings from a donor tree so that the grow rate and leave quality will be consistent. Nailing the trunks to the frame is ok, but some method of binding would help, too. But, the binding needs to be removed and replaced fairly often to prevent scarring. Bending out some apexes to be branches is a good idea, just need to not bind them.
All that said, it’s STILL probably better to do the traditional ”let grow and cut back” method. You’ll get better taper and a more natural looking trunk.
Good luck with your projects.