AusBonsai

Nebari is the Japanese word that refers to the base of the trunk and roots that we see heading off into the ground. Old trees have impressive nebari so we try to have similar on our bonsai. Sometimes the tree just hasn't given us all the roots that we would like. One solution is to graft to get roots where they are wanted.
There are several ways to get roots to grow where we want them. This series of pics shows how I approach graft seedlings to the trunk to get roots in place.

Here is the space I think should have another root or 2. Seedlings with a j curve at the base or with 1 or 2 strong roots on one side are ideal for this process. Cut bark from the spot you want to attach the seedling and cut a matching bit from the back of the seedling. Then nail the seedling in place so it will not move. I drill a hole with a tiny drill bit first to stop the seedling splitting but make sure the nail holds it really tight or the callus that forms as the cuts heal will just push the seedling away from the tree.
When the seedling is well grafted to the trunk the top of the seedling is cut off leaving just the roots attached to the tree.
If all goes well the roots will thicken and fill the space giving improved nebari.

great post.

Hi.

Good onya Phil, now i have more to learn.
Now were was i up to,mmmm

Regards.
Irish.

I was talking about this with Grant Bowie tonight, and he mentioned that with Tridents it is possible to use a root from when you root pruned. eg drill a hole slightly bigger than fat end of root into the trunk where you want your extra root, lightly taper the end of the root removing outer layer with a knife or sharp object, and then use a rooting hormone and insert into pre-drilled hole in trunk. Apparently he knows someone who has done this with roots from the year before's root pruning which were kept moist in a plastic bag and misted occasionally.


Sound like it is worth a try

Hey Luke, check out this link...http://bonsaistudygroup.com/advanced-gr ... n-trident/
This shows two techniques...one using a root that is still attached to the tree, and the other removing it totally before reapplying it as you mention Luke. Not sure of the outcome etc, but I found it interesting.
Hope you don't mind me posting the link on your thread shibui?
Cheers, Dario.

Thanks for sharing the link Dario, Ive just read through it and the posts it links to, and I found this one showing Boon root grafting a Ficus http://bonsaistudygroup.com/tropical-bo ... -rootwork/

Yes there are lots of ways of getting new roots on a tree. Roots can graft by themselves just like shoots above ground but, like shoots above ground you need to have reasonable cambium contact for it to graft on. I've grafted roots onto a crabapple by lifting a flap of bark and inserting a root with the top cut into a wedge but not all of them took. Approach grafting takes the guesswork out to a large extent as both bits stay alive until they unite. The downside is the scar that's left after removing the top.

The toothpick method is another way to induce roots.
Here's another way to get roots to grow where you want them.
This trident has a long root with no side roots. It would be better with lots of roots spreading out from it. Remove a strip of bark where you want roots to grow. (the roots will grow from the top of the cut) Pack spagnum moss around the cut area for best results And cover it all with potting mix to maintain moisture This method is like a partial below ground layer and works in most cases with trees that produce roots easily.

Thanks shibui, this is another fantastic and informative thread
Much appreciated:tu2:
Neil up untill now I have been doing partial ground layers to induce roots. But I feel I should extend myself and try these other techniques.
Being that there seem to be many different techniques, how do you decide which technique to use?...does it depend on the roots in question and the desired result, or do you have a favourite method?
You mention that approach grafting roots can leave a slightly unsightly scar...is thread grafting roots possible, or does that also leave a scar once the top is removed?
Cheers, Dario.
EDIT to ask a question rather than posting again.

Hi Dario,
Thread grafting is another way to add roots. The scar is usually smaller than with apoproach grafts buts it can only be used where the trunk or root is thin enough to drill right through. I used thread grafting for a while but many of the trunks I am working with are to thick to thread graft. The trunk on this tree is about 10 cm diameter and I don't have a drill bit that long that is small enough.

A couple of thread grafts I did, the top grafted on nicely and grew well but the root side did not connect and died off so I had a new scar and no new roots to show for it!

It does depend on the individual situation but at the moment I am favouring method 2 - the cut and spagnum. It seems to produce a mass of new roots that look like they will thicken up to produce a mass of good roots but time will tell. I thinlk it is worth knowing all methods so you have a choice.

Thanks shibui, that explains a lot
As I said I have not tried other methods but so far I have had good results with partial ground layers on turkey and cork oaks, ash,and figs.
Now to try the other methods....so much to learn
Cheers, Dario.

Have a few Japanese Maples that need some work. Which of the above techniques is the preferred method to successfully improve nebari on JM's...? Can I work them the same as a trident maple...? ....if not ... how much of the roots can be safely removed & when is best time to re-pot...?

Japanese maples should respond to any of these methods. They are a bit slower to respond but all these will work.
I don't cut JM roots back as hard as tridents but I do cut my trident roots back to just stubs which frightens most growers. Most people will be too frightened to cut JM roots far enough to cause permanent damage but the result may also depend on the health of the tree and the environment it has to endure.
I find it hard to give a meaningful measure because it depends what you find each time. Cut 2/3 off a root bound tree might not be enough. Leave 3cm long roots may be too little if the roots are not well ramified.

Great post, will go for these advice, have a few trees to improve, thanks for posting.