AusBonsai

Jamie wrote:...but surely the transport of nutrients from the bottom of the layer to the top is minute. but the if that was the case why do we botther with layers if basically we were just doing one big cutting?

Gday Jamie & Gerard!

Good question you pose here, Jamie, and it is one which leads me to explain to the best of my ability the theory behind layering techniques...

The short answer to your question is this: cuttings (generally thin cross-sections) transport water and nutrients to the foliage only by means of capillary action, in which the leaves transpire (lose moisture) which causes water to be drawn upwards. Assuming that conditions are right, this capillary action will be maintained until such time as the cutting will begin to form roots. In the case of layering, it is the intact xylem (sapwood) that actively supports the layer above (ie: the roots of the parent tree are 'pumping' water and nutrients to the layer as if the tree was intact and un-injured).

At this point, a diagram or two might be useful to illustrate the vascular workings of (most) woody tree species: Now, it appears that I've spent too long on that diagram, so I don't have the time to fully explain the theory. However, I can refer you to a number of articles which explain in relatively simple terms the inner workings of a tree, as well as the way in which layering works:

Layers Of A Tree (This is a great resource for understanding the function of each layer of tissue in a living tree.)

What Is Air Layering?

Layering Techniques For Bonsai

I think the best explanation comes from Andy Walsh (evergreengardenworks.com):

evergreengardenworks.com wrote:The removal of the bark, cambium, and phloem, but not the xylem, prevents carbohydrates and photosynthates from flowing down the trunk past the girdling site but still allows water and mineral nutrients to flow upward to the leaves. This keeps the leafy portions of the shoot from drying out and maintains them with an adequate supply of nutrients. The removal of the actively growing cambium layer prevents the regeneration of phloem and healing over of the wound. Because of this the carbohydrates and photosynthates flowing down the trunk collect at the girdling site. The presence of these excesses of carbohydrates and photosynthates (esp. auxin) at the girdling site, plus the presence of the water in the sphagnum moss, causes dormant adventitious buds in the area to grow into roots. When there are enough roots to sustain the shoot independently the shoot is cut off of the tree and then planted or potted.

I hope this all makes sense, and will try to answer any further questions regarding the air layering process.

Thanks.

Fly.

Hi Fly,
I have only just seen this sequence and find it very interesting, the use of the tiling things(exactly what are they), i thought they were like little vs . Have you tried this mehod just to make new roots on a tree thats is lacking in nabri.
Lynette

thanks fly

to be honest that i think has jjust confirmed the theory that a skirt around the xylem part of the layer would help prevent the tissue from trying to callous over, as the nutrients could still flow from the lower part of the tree to the top of the tree and then when the sugars and the likes are trasported back down can form new roots, i think this may have to be something to try on my next layer. i will photograph it and take progressions of it aswell as to see how it all goes!

one thing that has cleared something up for me which may have been a problem with my layering attempts in the past is the fact i may have gone to far on removal and taking the xylem aswell which would stop the flow of nutrients up!

jamie

Lynette wrote:the use of the tiling things(exactly what are they), i thought they were like little vs . Have you tried this mehod just to make new roots on a tree thats is lacking in nabri.

Gday Lynette!

The 'tiling things' are simply called tiling wedges - readily available at most hardware retailers. I have indeed used this method (minus the tiling wedges) to repair inverse taper and a lack of good surface roots: check this link. The result is still not a great tree, but it is getting better...

Jamie wrote:to be honest that i think has jjust confirmed the theory that a skirt around the xylem part of the layer would help prevent the tissue from trying to callous over, as the nutrients could still flow from the lower part of the tree to the top of the tree and then when the sugars and the likes are trasported back down can form new roots, i think this may have to be something to try on my next layer. i will photograph it and take progressions of it aswell as to see how it all goes!

Gday Jamie!

Good thinking here, I think... I understand where you're coming from, but I expect that the added effort you intend to make might be just added effort. Unless you were to try this on a tree has proved to be particularly reluctant to layer, you might be better off spending a little more time making sure that you are layering properly.

In the case of my 'failed' layer above (2 weeks later, and not even a sign of wilting), I have stated many times that it was my care that was lacking, as opposed to any procedural issues.

Nevertheless, I am very interested in seeing how you go: your inquisitiveness is the thing that innovations are made of!

Thanks, good luck and keep us posted.

Fly.

i see where ya coming from there mate, i think sometimes the biggest problems with air layers is how much is removed or if the layers are rather thin or thick like olive. you would think olive would layer quite well considering there ability to be flat cut and strike again but i did one a while back that was readily caloussing over, this could over come this prob, a willow leaf did the same thing aswell, it has taken me three goes to get it to have enough roots to remove the layer.

i will definatly keep ya posted though as soon as i have something worth while to layer, if anyone has any species that they think would be a good candidate let me know via pm

fantastic thread guys loved reading this one

WOOHOOO

Fly thanks heaps for this thread, it gives me inspiration to have a go with a few eucy's myself...never done any layering with them but have a few that could be used.

Matt

I am also turned on by this thread and i am layering Eucs and developing River Reds.

Any updates on these plants?

Jan