With spring approaching, I have spent quite a bit of time looking at my trees, collecting scion wood, examining blooms, pruning and so on. I seem to have the same issue on several of my cleft grafts and was looking for input. The grafts were made with pencil sized scion onto understock that was just slightly bigger. All took and calloused up last summer but as summer progressed one side of the cleft would dry up and slowly shrink away from the scion. The end result is a understock that is split open, a scion that is weakly attached on one side and the whole thing suffering from drying cold air of winter. I wonder if I am removing the tape too soon? I am tempted to leave it on all summer this time.
Some people leave the tape on all summer but I prefer to remove it around mid summer assuming adequate scion growth has occurred. If I unwrap a scion early I go ahead and wrap it back and wait awhile. After checking and observing grafts for awhile you will get a good feeling as to which ones are okay to remove.
So are you looking at the degree of callouse when determining if it is too early?
My first wrap of a graft is with parafilm, covering all the surface (never graft a large stump). Then, I secure it tightly with either Temflex or green garden tape.
I remove green garden tape by mid summer. I don’t even bother to remove parafilm. It breaks down by itself. I have not had a dry out issue. 99.5% of my grafts are cleft.
I’m surprised that you had the problem with thoroughly calloused grafts. I’d like to consider whether there are other issues at play here, but derned if I can guess what they might be.
Were all the compromised grafts on the same rootstock, or were they all the same variety? Did they all dry out on the same side, i.e., were they all facing a strong sun?
Just seems a little peculiar is all. But in the meantime, by all means leave the tape on longer.
I look at how much it has calloused but I move the scion around gently to see how secure it is attached. If in doubt leave the tape on longer. Most all unions will recover even if left on most of the summer.
Which cultivars were you grafting together?
I have similar issues on some peach to peach if I take the tape off too soon. I guess they are just very slow to heal.
I primarily use electrical tape and prefer to keep the tape on all summer when possible.
I lost Roxbury russet on a seedling rootstock and green gauge plum also on seedling rootstock that looks like it may not make it.
When I do a cleft I like the scion at least as big as the stock and slightly bigger seems better to me than smaller. Maybe one side is shriveling up because the scion was too small and only attached on one side.
Over time, I’ve come to decide that leaving the tape on all summer is best. I use electrician’s tape. I remove in late fall. Less tearing off of bark if I peel the tape then. If I do tear some bark, the wound still has a little time to lignify and harden off before the coldest winter winds arrive.
Do you have pictures of the problematic grafts?
Assumptions: mismatched sticks aligned flush on one side rather than centered, healthy r/s, healthy scions, perfectly sliced/fitted connection, sanitized ‘everything’, quick cutting/inserting/wrapping w/o delay so things don’t dry out, wrapping blocks Sun’s UV/gamma/Xray bombardment of unbarked tissue, mild temps wherein life activity is ramped up rather than dormant, cut pcs. compressed together snuggly and evenly flat-on-flat, chicken sacrificed to graft god 3 days prior to grafting, …well…maybe not…After having unwrapped a pear graft several weeks afterwards, once I saw the beautiful new tissue had grown all around the cut-up area, I left off the wrapping and sadly watched day-by-day as the new tissue w/o any wrapping slowly began to discolor, dry, and die. Never did that again. Since that rookie lesson, the wrapping just stays on for months.
Derby, when you say one side, do you mean one “flap” made when splitting the understock or are you talking about the side of the understock that is not aligned with the scion. If it’s the former, I’ve had that happen a few times when I wasn’t binding the finished graft very tightly or if I removed the wrapping too early. When I initially started, I was relying on parafilm alone to keep things together. This worked a lot of the time but the parafilm isn’t very strong so you cant really bind it tightly. I use parafilm now and then warp it with electrical tape to pull everything tight and get good contact, which results in better takes.
Yes that is what happens it callouses up on the side with the scion but remains open on the other side
Here is green gauge on a seedling , looking at the date stamp, it was July and I had removed the tape a couple weeks before . Sometimes I have a hard time leaving things alone…
Did that one make it? Post your ugliest (successful) graft!
It has so far, I believe I posted it in that thread, lol. Well so far I haven’t strangled a graft by leaving the tape on
I think there’s some mechanical stress there too, and leaving tape or rubbers on longer might solve that. I also suggest that when you cut the wedge you cut “shoulders” at the top of the cut- steep cuts more toward the center of the scion before bending back towards the point. So the profile of the wedge is not straight, but kind of an inverted, softly formed “L”, if you can envision that. That lets you pull the rootstock part of the graft in tighter against the scion. I can imagine a swelling, growing scion actually pushing the rootstock open a little. If that can happen (not sure it really does) then we’d have to keep the graft secured until the interior of the graft had plenty of time to knit- and I’d guess an entire season for that.
Just thoughts- might want to bounce 'em off of others.
I can see that and I agree, I think as the wood dries out it may shrink and increase that stress. The tape probably should have stayed on until fall
My thought would be that you need a lot more pressure on the union when it’s placed. And keep some pressure on it longer. I tie mine up with several layers of large budding rubbers pulled pretty tight. I want as much pressure as possible on the union at least for a few weeks. Then the sun will gradually rot away the rubber or I loosen it.after the graft is growing well. I like to have it shaded from the hot sun the first summer.
Doing it that way none of mine have opened up anywhere near that much. I have had a couple restricted when the rubber bands lasted into the second summer but they all survived.