Very interesting experiments!! How did you hold the blade when making a cut to rootstock? I have struggled whit this question too and i believe that very narrow cut all through the tissue is needed. If there is green in the middle of cut, Rootstock often tries to heal wound leaving the scion out.. I´ll post drawing of what i mean.

Here is drawing of what i mean with blade positioning.

Hi Jarpe

I used a diposable craft knife that had a straight blade, held as in the 'wrong' part of your diagaram. The width of the cut it made was not a problem as I even had to make the cut wider sometimes. The big problem was that there seemed to be so little tissue under the bark before hitting the pith, very very thin.

The way you show of cutting straight into the face is very interesting. But how do you get a flat surface if the blade is acting like a chisel making a groove in wood? That must be very tricky. Is it better for wider caliper rootstock? I always try and graft on a outward curve of the RS and a face that will make an easy cut. But you are grafting a lot more than me and older plants so I can certainly understand your need to maximise the effectiveness of the union.

Have you ever heard of lino cutting tools Jarpe? They are like gouges used in printing from flat lino blocks. I've linked a picture of the cuts they make. They are for sale at art or craft shops. Maybe if there was a big enough one and you sharpened it well it would make the perfect size face cut.

Here is a link that might be useful: {{gwi:2123699}}

Ok, then there is no problem in your method. In this kind of cases when scion is very small diameter, and cut is made this way, also scion´s contactsurfase is shaped similar way but opposite(not flat). I normally don´t use this method because i prefer that scion and rootstock are similar in diameter, then cutting surfaces are normal and flat.
Very interesting tools, something like that could probably be effectively used in grafting.

Nice work Severnside. Do you have any photos of the parent plant of 'Knaphill'? I don't remember seeing you post anything about it here previously. Must've missed it.

This is an interesting conversation. It is indeed tricky working with thin caliper material. On making a very thin cut in the rootstock, I find the resulting flap is very hard to work with and has a strong tendency to rip off at the base. One must be very gentle indeed! But remember you only really need to match up the cambium on one side, so if your cut is too wide you can still have a successful graft.

Alex

Ah, I get you better now Jarpe. So when the scion is thinner than the rootstock you like to make a grooved surface so that the scion sits in deeper?

Alex, thanks!

Here's the motherplant in it's old temporary site. Bought several years ago from the specialist Evergreen Conifer Center UK, now closed down. It was labeled P.menz 'Knapill' - 'A compact tree'

{{gwi:2123705}}

It was severely potbound and has not increased it's trunck diameter since, needing permanent staking. It lost it's leader bud a couple of years ago to birds so I promoted a new leader that then weeped to one side during the season, just folded. So it is a strongly weeping variety with intense blue colour. If I can get one of these grafts to take I'd like to send one to Edwin to compare with other Weeping Dougs and see if it is notably dissimilar.

And I hear exactly what you're saying about the thin flaps in small caliper grafts Alex. I lost a few that simply detached in my hand. I fully applaud all those who have succesfully grafted the tiniest scions. But it's interesting that you say only one side of the cambium needs to marry. I'll remember that.

In terms of the difficulty in getting grafts to take I would say they forgive a lot of errors in actual grafting (nature finds a way) but will not forgive poor aftercare. I'm lucky in that the southern UK climate is about as benign as anywhere for grafts so if people mimicked it around the world they'd be fairly safe.

You're a big time grafter, what are the biggest hurdles you face?

Thank you for the compliment though it's undeserved - I am a hobbyist and an amateur with but a few years' experience grafting. I'm doing about 200 grafts a year now which is small change.

When everything works right there are no big hurdles, it's more that every little thing has got to come off, one weak link will throw your success rate off. The parent plant needs to be in good condition, healthy and not too shaded for a good take rate. The understock need to be prepared properly. You've got to control moisture levels in the roots and humidity in the air. Temperature. Light level. Maybe for some reason the scion starts to push to soon. Or things get too hot in the chamber. As you point out, before care and after care are the most critical parts, the grafting is easy. So many little details to control, and any one of which gets too far off and it's a no go.

Like many skills, the more you practice the better you get, and this goes for all these other aspects too, as well as the grafting itself.

Jeah, Severn, that´s exactly it! Your experiments are thrilling. Please keep us informed!

What I've also learned Alex is that each graft is a story unto itself. Despite the best intentions it's how the knife travels, the scion sits and the wrapping that are the way the dice roll each time. I simply excuse myself as having used best practise and no big foul ups. I don't have a source for proper rootsock so I use one year saplings from Ebay that this time came from the highlands of Scotland. My absolutely critical grafts were done last year (the ones I would have no second access to the motherplants) so from now on there's more luxury to prepare the rootstock - I'll pay it more mind.

Jarpe,

That's a very important lesson you've taught me, there will be times I have mismatched RS to Scion sizes and I can see a notch would be better than flat faces.

Also; My Pinus mugo 'Jarpe's Last Chance' is doing very well and is just past the six month time off the motherplant. Fingers crossed it will push in a little over eight weeks time. It's been a long wait but remembering how green and sticky the tissues were I think it's a perfect time to graft (Last two weeks of July). Thanks again!

I´m happy to hear that, Severn! :)

Another thing that might work well with small diameter scions is grafting them onto sidebranches of rootstock. Then flat faces will do fine.

Here is earlier taken picture with graftingknife to show scale

Ah yes Jarpe, I have done this once. It's better though with grafts onto larger plants than single smaller 'starter' grafts. In fact now I am very conscious of making grafts look good as well as healthy. It seems the natural progression for a 'graftsman'. But it does add pressure to the operation. I wonder at the perfection of some of my bought plants, the grafts are almost impossible to see on some. I'm still to see how a graft grows and becomes part of the rootstock over the years, that'll be part of the enjoyment as much as seeing the plant grow tall.

I know the feeling when you see such perfect union. I know one very skillful grafter from Lappeenranta, Finland. His grafts are amazing. He uses relatively long cut, up to 8 centimeter.
I have also noticed that grafted scotchpine looks different than normal as a large, matured tree. There is no dark brown, barky few meter part in treetrunk but that orange/red part starts from ground level. i wonder why that is.