I was very surprised to have 2/2 takes with Oscar and 3/3 takes with Silk Hope. As it happens, I had made myself a hot callus pipe for use with persimmons. Even though it seemed unnecessary, I put the mulberries on the pipe as well.
Maybe the extra warmth helped?
This has been my experience as well. Geraldi grafts so easily. Oscar also fairly easy. Silk Hope fails most often and don’t really thrive even when the graft take.
I did 1 bud graft in early July and have a take. First time using buddy tape. I have started doing more bud grafts. Just selections I found on my property.