Thread grafting

[Bougy Fan]

Hi Everyone
I have a bougy that I want to try threadgarfting some branches in places that I want. I have some lower branches that I can thread through higher where I want them. I have looked at Harry Harrington's site and I have one question. After drilling the hole through the trunk and before threading the scion through does it need the cambrium scraped back on the scion where it will be in the trunk ? Or will it graft with no special treatment ? Does anyone have any experience ?


Tony

[shibui]

I haven't threadgrafted a bougy but have used it with other trees.
If the bark is not scraped from the scion it will usually still graft after the scion thickens and fills the hole but will take longer.
When cambium is exposed and matched up well it will graft quite quickly.
I suppose bougie should still work the same way.
Good luck

[Jamie]

being a boug it wont take long at all, just make sure your hole is big enough not to damage the buds but not to big it will take ages to make contact with the hole.

once it thickens enough it will graft and eventually be fed via the trunk. leave it on until you can see that the branch has swelled sufficiently to the trunk and is being fed by it. only then when you are positive that it is being fed by the trunk cut the branch of that was feeding it while thickening.

[Bretts]

The most important thing is to get the branch through the hole without scrapping to much cambium or buds off as this will weaken or kill the branch. Depending on the bud size of the species you need to make the hole big enough. A little trick is to place a wedge in the hole after pushing the threaded branch against the side of the hole.
This is left in the hole and just trimmed off at a later date.

[Bougy Fan]

So what about sealing where the scion enters and exits ? Harry recommends cut paste - would it be more to secure the scion so it doesn't move ?

[Bretts]

Ah yes sorry. It won't hurt to use a sealant. I never used to but I do these days as it doesn't hurt. It is to seal though not to stop movement.

[Taffy]

I was going through this section looking for something else, but when I noticed Thread Grafting, it drew my attention. I've done quite a bit of thread grafting, and so far I've only had one failure - and that was because my dog walked past it and broke the growing tip off!

There is one very easy way to protect the growing tip while threading it through. Get a straw and split it down one side. Open it up and put it round the donor branch. Make sure the growing tip is inside the straw (not protruding at all) and slide the straw through the hole. Once the growing tip is out the other side of the tree/branch. Hold the donor branch in place behind the straw (and behind the entry point) and pull the straw all the way through. Voila! the growing tip is completely intact.

Quite often the straw is too large a diameter for the branch you're threading through. No problem, with it split up one side it can be rolled up like rolling your own cigarettes until it it tight against the branch.

I do scrape the donor branch back to green but only on the underside and only where it comes in contact with the edge of the drilled hole. I believe it enables the branch to fuse faster as both cambiums are in contact with each other right away.

I don't seal the holes at all because I think that if any sealer gets in between the branch and the tree it could hinder or stop them fusing. What I do is wrap grafting tape in around the entry and exit points in figure of eights from exit to entry, and then to ensure the whole thing stays in place I wire it in position - a few turns round the branch before the entry point, around the trunk to the exit point and then a few turns round the exit part of the branch - not in a circle around the trunk, only directly around from entry to exit. I've never had one move doing it that way. Oh and yes, and I also I wedge it in place at the entry point with a bit of twig from the same tree

Hope this has added a bit more to the advice already given.