Root Grafting on JBP

[ianb]

Hi All,

I have a fairly nice shohin JBP that is in need of roots on one side as it was an air layer that didn't really root all the way around. Does anyone have any experience grafting seedling pine roots onto an established pine? Can you share any tips or tricks?

Here's the tree before cut back and wiring yesterday...

 

[Leo in N E Illinois]

Very nice tree. I have no experience with root grafts, sorry.

 

[Bonsai Nut]

I have no experience actually doing a root graft on a JBP. I would assume it would be similar to a standard approach graft(?) My biggest question, based on your tree description, is the health of the cambium on the side of the tree you are wanting to graft the roots to. Is the cambium healthy if there are not any roots on that side of the tree?

 

[AlainK]

I have no experience either in grafting roots on a JBP, but I had plenty of seedlings, and a friend that spent several weeks in a Japanese nursery asked me for one for a graft.

No news so far, he grafted it last summer, I didn't see how it did, and he told me that so far the grafted 3-yr-old seedling "trunk" hasn't been severed yet: I'll let you know when he does, and what the result is.

 

[ysrgrathe]

I've heard from my teacher that it isn't done, but not why.

 

[Dav4]

I've attempted them on an old JBP via approach grafting... all failed, mainly because I pulverized the seedlings attempting to fix them solidly in the wedge cut in the base of the receiving tree. I'll be attempting more on a different tree, a pre-shohin JBP, this spring, and will hopefully have better results.

 

[AlainK]

I've heard from my teacher that it isn't done, but not why.

Can't figure out why either if it can be done.

 

[ianb]

Thanks for the comments, I guess I'll give it a try this coming spring and see how it goes. I've done root approach and thread grafts on maple but have a feeling it won't be as easy...we'll see.

Of course I'll update this thread with the results.

 

[MichaelS]

I have done it a couple of times. You need the right seedling, the correct tool - it must be about 1mm or less in diameter wider than the part of the seedling to be used. It should ''just fit in if pushed a bit. not too loose or not so tight that you end up mangling the bark of the seedling. (This part is the most important of the whole operation), and some grafting wax. (not Japanese sealer)
A bit from a milling machine works well. Something parallel which cuts on it's side. Make the groove so the seedling fits in completely. The work must be very neat or it won't work. As it grows it will have no option but to unite with the tree.
Lightly scrape the bark of the seedling until you see green (this is not essential)
You will need to partly bare root the tree to do this. You need to totally seal every exposed cut surface - from underneath as well as from above. This is vital or the tree may heal itself before there is a union. Even so, the pressure from the expanding seedling should eventually force a union.
If done correctly, the seedling will not move when it is inserted into the groove. If it does, the groove is to wide or the seedling is too thin. Find a new seedling (have a few on standby)
Let the seedling grow without pruning for a couple of years. If it's in the way you can wire it down but don't prune it.
When you are reasonably sure it has united with the trunk, you can progressively start to reduce the seedling foliage until you finally remove it 1 or 2 years later. The seedling should be about pencil thickness.
You can do as many on these grafts as you like at the same time.

 

[Bonsai Nut]

@MichaelS How deep does the groove need to be? Is the groove all the way through the bark and the cambium layer of the parent tree?

 

[MichaelS]

@MichaelS How deep does the groove need to be? Is the groove all the way through the bark and the cambium layer of the parent tree?

Yes the groove goes right into the wood until the seedling fits in like a bolt into a socket. So the points of eventual union - or cambium contact of both seedling and tree - are at the top and the base of the slot. It's kind of like a thread graft without the ''threading''.

 

[ianb]

Hi Michael,

Thanks for this, do you pin the seedling in or just rely on the fit of the seedling?

 

[MichaelS]

Hi Michael,

Thanks for this, do you pin the seedling in or just rely on the fit of the seedling?

Depends on how tight it fits in. If you think it might be moved or knocked out of position then you may have to fix it somehow. Pins or a wedge shaped stone hammered into the slot hard up against the seedling should work. Just remember that it will take a full growing season to get really tight and fixed and another one to start the joining. The longer you leave it there the better the results will be. I did a similar thing to red pine which was too tall but this time I used a branch and approach grafted it to the trunk using the same slot type of arrangement. It has been 2 years and I still have not even looked at it yet. I think you can average these grafts out at about 3 years before things are fixed enough to work on again. (with pines that is)

 

[River's Edge]

I've attempted them on an old JBP via approach grafting... all failed, mainly because I pulverized the seedlings attempting to fix them solidly in the wedge cut in the base of the receiving tree. I'll be attempting more on a different tree, a pre-shohin JBP, this spring, and will hopefully have better results.

Tips that will improve your chances include:
1. Instead of a wedge cut create a channel that is slightly wider at the back then the front. Then when the seedling grows it locks itself in.
2. Pin the seedling using grafting pins that hold the edge of the seedling not through the seedling.
3. Grafting caulk stays flexible longer than wax and keeps the joint air tight. Also less chance it will migrate into areas of the cambium that you wish to join. For that reason do not use liquid sealers.
4. Time the grafts for when the pine is waking up and beginning to actively grow, late winter early spring. this gives a longer growing season to heal and less interference with sap on the channel and cut.
5. After creating the channel take time to cut cambium edges as clean as possible with the sharpest blade you can find.
6. Gently scrape the edge of the seedling to expose some green where it meets the trunk cambium.

 

[garywood]

Ian, some good advice here. I've done quite a few and have seen a few also. What is the age and size of the scions? the reason I ask is the older or larger it is, the more care needs to be taken when judging the depth of the cut. I've used newly sprouted seeds with good success and they blend in rather quickly. The cut needs to be deep enough for the seedling to be at a depth where the outside of the seedling trunk is aligned with the inside of the cambium. Lightly scrape the seedling and secure. The channel needs to be tight but not so tight that you have to force it. I use a short section of chopstick placed on the seedling and staples to secure the chopstick, not too tight, just snug. seal with putty and lightly cover graft area with long fiber sphagnum to keep the area moist.

 

[Drew]

really good thread here @ianb, I was planning on trying the exact.. thanks for all your tips. have any of you got any pictures of successful root grafts?

 

[Divide_by_zero]

Hi All,

I have a fairly nice shohin JBP that is in need of roots on one side as it was an air layer that didn't really root all the way around.

@ianb , please tell me more about the original air layer on the JBP, maybe a different thread.