I really have to be patient with some of my grafts! Some of them required more than a year to push out! I can’t explain it but for as long as the wood is green underneath the outer bark, even if they’re dormant, I know they’re still alive so I didn’t nip them off and let them be until forgotten. Now I’ve noticed growth from my grafts that I thought were long dead, they’re showing signs of life more than a year later.
That is good to know, I have 3 grafts that I though were dead but just didn’t get around to removing them. They could still be dead, but I am going to wait till spring hits and then decide rather than clearing them away early.
On stonefruit I noticed that if a graft is dead and left on the tree for a long time (months), a dark area in the heartwood would develop near the graft union and spread to the rest of the branch where the graft is located. I don’t know what is the nature of this heartwood darkening but it doesn’t look good, so I try to remove dead grafts sooner rather than later.
On my citruses, I have observed sometimes, the bud would take and remained green but won’t sprout until after about 18 months!
I have grafted plums with scions when trimming excessive growth in August. The graft frequently heals but the scion’s buds don’t grow till next spring. Similar principle to a late summer chip bud.