graft post-mortem questions
I started whip and tongue grafting pear trees (mostly onto well established wild callery seedlings in the field) this year on March 7, and I've had enough time now to see some failures and to see some different patterns in the failed grafts. I'm hoping some of you on this list can help me understand what happened and maybe how to avoid repeat problems in the future.
Almost all of my grafts began to grow this year with the main exception of one batch of scionwood. The cambium layer definitely looked green still when I grafted, but none of the 3 grafts I attempted ever grew at all. It seems like the problem probably had something to do with the scionwood before I ever grafted it.
The other problem I had was buds that began to elongate and in some cases even open up into unfurled leaves (just like the grafts that still look good) before pretty rapidly wilting and dying. I've never had grafts fail in that way before. When I unwrapped the rubber bands to look at the graft union the area under the rubber band has mostly been black (compared to mostly normal brownish-gray bark on the rootstock and more young-greenish color on the exposed part of the scion.) I've wondered if I could be wrapping my grafts too tightly or if I should have removed the rubber bands when the buds opened up? Mostly the failed scions appear to have knit together with the stocks neatly, but I haven't pulled them apart yet to see better.