Turkey Creek
5 year old buck +
I have one like that as well. Not sure there is a definite rule. I plan on leaving mine for awhile yet. I have to admit that gap in the middle is one reason I dont like cleft grafts, though I did use that method this year and have had good success with it so far. Seems like a long term weak spot where the gap is. It would be nice to see a study of tree health and durability of the graft as it relates to the grafting method as a tree matures.