It could be that the answer to this question is either hotly debated or, conversely, ridiculously obvious but I am planning for the winter and pondering my options. I did a bunch of cleft grafts last year and many of them did quite well. I am debating how to prune them.
The first is a dual cleft graft, with Dapple Dandy dominating wildly over Black Ruby on Mariana 2624. The Dapple Dandy side is a whip over 5 foot tall, and the Black Ruby side is closer to 3. I was thinking about heading the DD side to roughly a foot from the graft scar, and the BR side to a foot taller than that, leaving me with a 3 foot tall Y with the North and less dominant side high. I am also considering letting the Black Ruby have a different tree and cutting it out completely, and heading the DD to just above the union to try to straighten up the spreading between the Y I did this year. I live on a suburban postage stamp but I have tiny trees wedged in all over in preparation for a glorious future.
I have some first year apple whips growing in the front yard, which I was considering running up to about 7 foot (on emla 111) staked if necessary, that I was thinking about letting branch naturally after reaching the right height, with spreaders for form. I know that I have lost strawberries to neighborhood children so I don’t mind getting branches above 4 foot asap. I know I will have losses from the front yard but I hope to keep pilfering from the back down with an “honor” tree in the front.
As a small scale home hobbyist, I was also wondering about branch height. Squirrels are going to get to my tree, and rabbits are common but not ravenous in my environment. I was thinking of putting scaffolds closer to 18 inches, and wondered if there’s a really good reason not to besides mowing under and rodents?
Many people prefer not to let two grafts grow on an individual cleft graft. Often times people will insert two sticks of the same scionwood into the cleft and keep the one that is growing the best while pruning the other out. As for the apple whips, make a cut about 16 inches above where you want your bottom scaffolds to be. It will force side shoots which you can then train into scaffolds. The shoots near the cut will want to grow straight up and you can choose one of them to be your new central leader. The lower shoots will want to grow with more open angles and that is a great time to use a cloths pin to train them with open crotch angles.
The usual reason for two sticks of wood into a cleft is assurance of at least one take. However, if you expect that you may want to eliminate one of the varieties after evaluating them you can leave them for now, but if you try to subdue the more vigorous graft you will postpone its usefulness as you will be taking from Peter to serve Paul. I would prune for earliest crop (as little as possible) and hope the runt survives while assessing Dapper Dandy. If Dapper sucks you can remove it and let Black Ruby show its stuff if it hasn’t yet. In the end you probably should choose one or the other. One will need to dominate to sustain a strong union anyway.
That makes total sense. My logic was similar, if draconian, as I had two scion sticks and the second rootstock was dead in the middle when I split it to graft. I was left with one prime location rootstock and two different kinds of scion wood. I was curious if they would simply grow into each other. They do seem to have done that a little bit. I have a St Julians rootstock I can try to put the Black Ruby on later and just make sure that the Dapple Dandy performs. It’s an accidental root cutting from a transplant that took off in a raised bed, so now I need to figure out how to get it out of there without uprooting all my garlic.
Grafts that give you at least 12" of growth the first season usually survive, so by the second season you can remove the competing growth once both are in vigorous growth.
A) cut flush to the knuckle, leaving a collar from scion 2
B) physically break it out of the union, exposing the callous for the other graft potentially
C) Cut back to the union trying to cut into the joint itself so there’s as little as possible left in the joint