missing a basic grafting concept, apparently...a little help?

[Zafra]

Just watched this video "Veneer Grafting with Walter Zill". https://www.youtube.com/watch?v=fp_QOOLRTcI Great stuff, but now I'm confused. My understanding was that the cambium layer is the green line you see just under the bark, and that the goal was to line up the green line on the root stock with the green line on the scion. That would mean that lining up the edges would be key to success, and it's usually emphasized in the tutorials on grafting I've seen. But Mr. Zill centers his scion in a cut that's significantly bigger than the cut on the scion. How does that work? Can someone help me with what must be some basic concepts that I'm missing? Thanks!

[behlgarden]

his video shows scion to much bigger rootstock, it is not claft. In Cleft when your wood is same as rootstock, obviously green bark will align to green bark.

however, what grafting means to have cambium contact, cambium layer is beneath bark.

[Zafra]

Right but I thought doing a veneer graft you still have to align the edges of the cut, because that's where the cambium layer is. I thought that was necessary with any graft.

[BajaJohn]

It's a bit of geometry. With a veneer graft you are slicing a bigger rootstock along the perimeter of the circular layers of bark, phloem, cambium etc. so the cut is at an angle rather than straight through the layers which makes them appear thicker. A thinner scion is cut more along the centerline so the layers are thinner and all the layers won't line up exactly with the rootstock. The cambium layers are the important ones to line up. The bark and phloem layers on the outside of the cambium won't be as thick on the scion as they are on the rootstock so it is likely that some veneer grafts won't line up exactly.

[Zarafet]

On my veneers I match one side of the cambiums and they take

[John Travis]

On my veneers I match one side of the cambiums and they take

It does seem like even with cleft grafts that matching only one side of the cambium is enough to get grafts to take. 

In fairness I watched the video and thought that the cuts on the rootstock were a little wide, but when the rootstock is that bug I imagine it gets harder to make smaller cuts.

[CA Hockey]

I don't think they have to line up perfectly all along the edges. I have read on this forum that some members recommend the scion actually be a touch larger than the recipient wood/cut. I suspect that the more the cambium layers match, then the better the chances of success. so long as there is a connection between layers (i.e., the two cross and intersect at one or 2 points) and the rootstock is pushing sap, then you've got a chance at success.

Best of luck
K

[Zafra]

Thanks for all the responses, guys. But I encourage you to watch the video again, specifically the second graft he does where you see clearly that the edges are not lined up at all, and in fact he's checking to be sure that the scion is centered in the cut on the rootstock, so it doesn't touch either edge. I still don't understand how that's going to work, even though clearly it does.
I almost always have larger root stock than scions, so this should be the right technique for me and I really want to understand it.

[fyliu]

Thanks for all the responses, guys. But I encourage you to watch the video again, specifically the second graft he does where you see clearly that the edges are not lined up at all, and in fact he's checking to be sure that the scion is centered in the cut on the rootstock, so it doesn't touch either edge. I still don't understand how that's going to work, even though clearly it does.
I almost always have larger root stock than scions, so this should be the right technique for me and I really want to understand it.

What time are you referring to specifically? I looked at the graft at 7:30 and it looks fine. But I'm not sure if that's what you're talking about so it's better if you told us where.

Anyway, his technique is to remove only the bark, so anything exposed in the center is the cambium layer. Anywhere he attaches the scion is fine as long as it's in the middle and not on the sides.

[TREESNMORE]

Zafra
 This is Walter Zill he is showing how to top work old trees. He is a expert  at grafting trees. I am like you I try to match up the rootstock and budwood as close as I can. 

[Zafra]

Look around 13:28 and onward. That shoot he's grafting on isn't much larger than a rootstock might be, so it doesn't seem to be an issue of top-working vs grafting a seedling.

[fyliu]

Yes, he has to center it on the rootstock cut as much as possible. That's where the cambium layer is. The whole center is the cambium. The sides are the bark.

Usually, people cut it so that there's wood, cambium, and bark. Zills cut it so that there's only cambium and bark exposed, so anywhere that's not bark is cambium.

[Zafra]

But isn't the cambium green? The cut looks white to me...

[Chandramohan]

All the Jackfruit budding in India is done this way. The opening on the root stock is much bigger than the bud patch. And when it is done by an expert, the take is more than 99%.

[fyliu]

But isn't the cambium green? The cut looks white to me...

I think people say it's green to make it easier to find. It's a single layer of cells that differentiates into bark and wood cells and it's hard to tell what color it is. The layer or bark next to the cambium layer is probably green for most plants.

[behlgarden]

Cambium layer is the first layer beneath bark. so on green wood and rootstock, lining up of bark lines up the cambium layers. However if you do veneer or cleft on more matured brown rootstock, you have to pay attention as you have to get scion onto white cambium of rootstock.

[00christian00]

But isn't the cambium green? The cut looks white to me...

I watched the video and was puzzled too, but I think I understand what's the catch you are missing.
You are watching the exposed wood in the video, but what he is trying to match is the cambium in the unexposed part where the scion is inserted.
He basically made a cut just as deep as the bark, meaning the scion is in direct contact with the cambium.
Basically what he did is the same as this, with the exception that he didn't cut the whole branch:


The confusing part is that he made that huge cut but I guess that is just for convenience to make the scion move less.

[Zafra]

I think that must be the case, but in the second graft he's cutting on green wood, and for there to only be cambium exposed there the cut would have to be way shallower and therefore way narrower. Unless the cambium goes a lot deeper than I understand it to go. Maybe that's my problem. When I've cut for a veneer graft I always look for that green line around the edge of the cut and try to line up with that, and getting the cut to be the right size when the rootstock is bigger than the scion is a total PITA. To have only cambium exposed, it seems like you'd have to just scrape the bark away - any flat cut will go past the cambium in the center and leave only the outline cambium around the edges. That's what I've always thought, but apparently I've been wrong, which could partially account for my miserable failure as a mango grafter! I've had success with avocado and citrus, but nada with mango. Since I have to bring the scions a long distance, I know scion viability is probably about 80%+ of my problem. So with the remaining 20% that might have a chance of making it, I want to understand the technique I'm using and do it well. Like I said, since my scions are almost always smaller than my rootstock, veneer seems the way to go.

[kh0110]

I'm as bewildered as Zafra. Not sure why people keep saying that there is cambium left in Zill's cut. There is none as he really cut into the rootstock, not just removing the bark as in t-budding or top working a tree.
This technique must works because Walter Zill is using it, so no doubt there, but it goes against what we're taught about cambium matching.

[behlgarden]

I'm as bewildered as Zafra. Not sure why people keep saying that there is cambium left in Zill's cut. There is none as he really cut into the rootstock, not just removing the bark as in t-budding or top working a tree.
This technique must works because Walter Zill is using it, so no doubt there, but it goes against what we're taught about cambium matching.

Thera,

I do veneer all the time and always cut at an angle from outside to 50% into the wood at say 30 degree angle. I get very high success rates, plus the take looks like a branch and not vertical veneer.

[kh0110]

Thera,

I do veneer all the time and always cut at an angle from outside to 50% into the wood at say 30 degree angle. I get very high success rates, plus the take looks like a branch and not vertical veneer.

I'm questioning the success of such graft, Behl, we know it works and Walter Zill proves it in the video. I'm just pointing out that apparently cambium matching in a graft is not all there is to it as there is no cambium matching in Zill's grafts in the video.

[fyliu]

Between 11:40 and 12:00, he cuts into the rootstock, only cutting off the flexible bark. You can see the round wood core underneath. All around that core is the cambium, as you know.

[sapote]

6:00 minutes, after trying a second cut he said "that's better. The wood is below this damp, juice layer..."

Apparently his first cut was not deep enough (even it look white or wood to most of us). So He wanted to cut right at the cambium layer and it is located at the center of his cut, then the smaller scion with two strips of cambium will touch the root-stock wider cambium center. Make senses.

[Zafra]

I'm as bewildered as Zafra. Not sure why people keep saying that there is cambium left in Zill's cut. There is none as he really cut into the rootstock, not just removing the bark as in t-budding or top working a tree.
This technique must works because Walter Zill is using it, so no doubt there, but it goes against what we're taught about cambium matching.

Thank goodness it's not just me!

[sapote]

But isn't the cambium green? The cut looks white to me...

I watched the video and was puzzled too, but I think I understand what's the catch you are missing.
You are watching the exposed wood in the video, but what he is trying to match is the cambium in the unexposed part where the scion is inserted.
He basically made a cut just as deep as the bark, meaning the scion is in direct contact with the cambium.
Basically what he did is the same as this, with the exception that he didn't cut the whole branch:


The confusing part is that he made that huge cut but I guess that is just for convenience to make the scion move less.

In this drawing of the T-budding graft, I am wondering....
With the bark removed, the cambium on the rootstock is exposed, but the surface is a curve around the trunk and not a flat as a cut. So with a flat cut on the scion, its cambium exposed on the flat cut is only available as a inverted U shape. So only a tiny bit of cambium at the top of the inverted U is touching the rootstock's cambium, and the scion's two long cambium strips are up in the air not touching the rootstock curved cambium. This leads to much less cambium contact.

So why not use Zill's verneer grafting instead of the traditional T-budding for top working?