Trident Grafting for Improved Nebari...?

[Bonsaiforest]

Hello I have a few tridents that are in serious need of more advanced and evenly spread root system/nebari. Just wondering what the advantages of thread grafting & approach grafting would be. Which technique would leave less scarring , & which of these grafts would take to tree more easily. Is there a higher success rate with one or the other or is it just pot luck. I have previously seen specific posts on this topic related to improving trident nebari, but I'm yet to find it again. I'm sure that there are those that have had great success so your thoughts would be a bonus and a great learning experience for all of us here on AB. If any of you have any advice or can point me to a related post it would be greatly appreciated.

Cheers

[shibui]

I've used a number of techniques for adding roots to tridents. You will probably find you'll need to use several different techniques depending on the size of the tree and position you want the roots.

1. thread graft: Tends to leave less scar but in a number of cases the top end grafted and grew well but the roots end failed - probably my technique. Can only be used where you have a drill bit long enough to drill through the trunk so can be difficult on thicker trunks - You'll be surprised how long the drill bit needs to be to go right through a medium sized trunk. You don't always need to go straight through the trunk - look for places and direction where the hole will be shorter.
2. approach graft: Donor seedling needs to be held very firmly against the trunk to work. If it can move the healing trunks will push each other away and graft fails. That usually means drilling through the donor trunk and pi/nail/screw the smaller trunk to your bonsai. Therefore donor seedling needs to be large enough to drill and fasten. After healing for a year or 2 the donor seedling will be 1-2 cm diam and leaves a decent sized scar when the top is cut off. Can take several more years to heal over. Some approach grafted seedlings just don't seem to grow very well - probably root competition from the larger bonsai? and can take 2-3 years to grow enough to graft onto your bonsai.
3. Ground layering: You can induce new roots by wounding the trunk where roots are required. I find this particularly useful where a few new roots are needed in one area. You can just do one section, no need to go all the way around the trunk. 'toothpick method' achieves similar results.

Here's a thread showing approach grafts and the part layering methods on some of my tridents viewtopic.php?f=7&t=15938&hilit=+trident+roots+strip

[kcpoole]

About the only method I I have used is a tread grafting to get new roots on a trident about 4 inches in diameter.
About 2 years ago, put in 5 thru the base of the trunk and all but 1 has taken and the tops have been cut off.

i will probably have to add a few more this year maybe and As shibui metnioned, the drill length can be an issue ans you need to drill diagonally down thru the trunk . Long series bits may need to be purchased specifically for the job

Ken

[Jow]

Have a look at my blog. I cover a number of techniques in detail.

That said, the more a do the more I prefer approach grafts if filling large gaps.
Often after a thread graft takes it stops thickening and so doesn't fill in areas very well on advanced trees.
Approach grafts can be grown out to thicken the root sections prior to cutting off the top growth.

After a few years both methods produce very little scaring if good technique is applied.

To get good results either way you also want the tree to be growing strongly an not in a ramification maintenance cycle.

Joe.

[Bonsaiforest]

Thanks Neil, Really appreciate your detailed information, pros/cons of each type of grafting. Perfect post & what a cracker of a tree...!!!Gives me the confidence to move forward. Toothpick seems the safest and from what I understand it will leave the least scarring. I do have a couple of trees that I can work on. I'll use thread grafting on 1 & approach on the other...It will be good practice for me & hopefully will achieve good results. For my third trident (that's more advanced) I'll go with toothpick method as it will be chopped again in mid summer + branching cut back & don't think it will have enough vigour to hold onto thread or approach grafts.

Thanks Ken, I was also thinking of adding approximately 5 thread grafts to one of my trees. Do you have to seal both entry and exit holes when thread grafting for nebari...? Was thinking that it may not be necessary for paste to be applied at base (entry point) of trunk if you have a really tight fit...Or would that just risk of infection an rot occurring...?
Also how long did you leave the thread grafts on before removal...? & can you pick up long series drill bits from bunnings or would it have to be a specialty supplier...?

Thanks Jow, Just found your blog & post"using map pins" Will get onto to reading tonight & then catch up on your other related posts...Cheers

Would it be ok work on these techniques mid winter or would it be best to wait until just before spring...?

[shibui]

Any time before the buds start to swell for thread grafting. You'll be surprised how big the hole needs to be just to get the dormant buds through. Once they start to swell you'll need an even bigger hole so it will take longer for the seedling to fill the hole and start to join up.
You'll have to bare root both the tree and the donor seedlings for either thread or approach grafts so whatever time of year you're comfortable with. I do mine any time from mid winter through to bud burst.

I have showed that sealing cuts does make a big difference to how quickly they heal up so I think that sealing both entry and exit holes would pay with quicker takes, even if it is a tight fit.
You should be able to get longer bits at any hardware shop including the green shed.
Thread grafts are left on until you can see swelling around the graft area. That usually shows that it has joined up. If in doubt leave for a bit longer to be sure. Note that in this case you need to wait until the root side has healed up and is growing strong. If you cut the top off and the root side has not yet joined up it will probably die off.
It may take just a few months if your trees are growing well but could be a couple of years if growth is very slow.

[Bonsaiforest]

Thanks Neil ...much clearer now... Cheers

[kcpoole]

Like Neil I also use cut paste on all my cuts over 6mm and on all grafts as well

Ken