Restarting a failed airlayer in mid summer for fall separation

[pandacular]

I have a layer of sphagnum on top, and am watering it when it dries. Similar to my trees, but perhaps keeping it a little more wet.

 

[Wood]

I'm not a whiz at air layering or the science behind root development, but it seems like that's probably fine. You don't want to keep a pot sopping wet because oxygen won't get to a root, it'll die, and then it'll start to rot and cause issues. If there's no roots yet, you don't really need to worry about the root rot issue. I can't really imagine a standing layer of water inside the suspended pot either, so watering frequently probably isn't that much of an issue?

 

[leatherback]

Take the ring of bark out, then use knob pruners to bite away at the cambium around the top in a complete ring.

This is a tricky operation though. By doing this, you are actually breaking part of the upwards sapflow. For thinner younger branches this can cause problems.

 

[pandacular]

upwards sapflow

upwards ~= xylem?

For thinner younger branches this can cause problems.

how thin? would you say it's a matter of percentage of the mass under the cambium that is removed?

 

[RJG2]

upwards ~= xylem?


how thin? would you say it's a matter of percentage of the mass under the cambium that is removed?

Right, you don't want to remove all the sapwood, or you essentially have a large cutting.

I definitely just scrape thoroughly.

 

[Wood]

This is a tricky operation though. By doing this, you are actually breaking part of the upwards sapflow. For thinner younger branches this can cause problems.

That's why I added this second sentence to my original post:

Doesn't need to be deep -- especially with yours, i'd only go maybe 1/8" or a smidge less

Apologies for not providing enough context

 

[leatherback]

That's why I added this second sentence to my original post:



Apologies for not providing enough context

I am still not convinced it is a great technique..
I would not recommend someone go out with knob-cutters to reduce the sapwood. It is not needed, and it risks the top.

 

[Maiden69]

I am definitely against cutting any of the sapwood/xylem, as that is what brings nutrients to the top part you are trying to air layer. What I have done in the past is add a few coils of aluminum wire right against the cambium on the air layer, which will force the callous outwards. And recently adapted a method I saw on BonsaiQ (video below) and other Japanese videos, where they use a thick mylar (7.5mil or thicker), cut a groove in the cambium with a bonsai saw and cut a circle smaller than the branch you are air layering and push the mylar inside the groove. Kinda like what @sorce did with the CD's, but inducing the cut instead of "choking" the branch. I will probably post a thread once I get to separating the branches.

There is another video (not sure if they do on the one below) where they recommend also pruning radially the roots developed on the air layer late summer and then separating in spring (or maybe it was pruning early summer and separating in fall, both make sense to me) which ends in a lot more roots than by leaving them alone while also maintaining the foliage through the xylem from the parent tree roots.

 

[pandacular]

A small update on this project: I haven't seen any signs of roots in the pot, but I do see a significant acceleration of growth in the "new apex", just below the layer. There's probably 6 vigorous, new shoots near this point, which to me would indicate that the girdle was affective.

 

[Orion_metalhead]

I am definitely against cutting any of the sapwood/xylem, as that is what brings nutrients to the top part you are trying to air layer. What I have done in the past is add a few coils of aluminum wire right against the cambium on the air layer, which will force the callous outwards. And recently adapted a method I saw on BonsaiQ (video below) and other Japanese videos, where they use a thick mylar (7.5mil or thicker), cut a groove in the cambium with a bonsai saw and cut a circle smaller than the branch you are air layering and push the mylar inside the groove. Kinda like what @sorce did with the CD's, but inducing the cut instead of "choking" the branch. I will probably post a thread once I get to separating the branches.

There is another video (not sure if they do on the one below) where they recommend also pruning radially the roots developed on the air layer late summer and then separating in spring (or maybe it was pruning early summer and separating in fall, both make sense to me) which ends in a lot more roots than by leaving them alone while also maintaining the foliage through the xylem from the parent tree roots.

Next time I layer a vigorous tree such as trident, Im girdling more than is necessary and using a zip tie after scraping low on the girdle. That should stop bridging far enough down the girdle that its east to remove/cut off during air layer separation.

 

[Maiden69]

Next time I layer a vigorous tree such as trident, Im girdling more than is necessary and using a zip tie after scraping low on the girdle. That should stop bridging far enough down the girdle that its east to remove/cut off during air layer separation.

One thing I have been considering, and will probably test soon is to use aluminum tape on the cut below the air layer, that will prevent any callous from above to ever reaching the bottom and bridging. As far as using a zip-tie, I would rather use a thick 6mm or larger aluminum wire right against the cut edge on the air layer. This will help girdle and produce the swelling better than a plastic tie would. There is more material present to prevent the callous from rolling over.