The science of air-layering

[Forsoothe!]

If I remove the cambium on the trunk of a tree to air layer, then presumably I would be stopping further root growth below that point right? I did an air layer on a bloodgood a couple of weeks ago and I've noticed the tips of the leaves drying out lately. I believe this started not long after the air layer. I worked the roots a bit sometime in February. So I am thinking may be the roots aren't keeping up with the foliage growth?

One major insult per 12 months. Oops!

 

[namnhi]

Quick question on JM airlyering. I have done plenty with success but I have always try the upper cut at around the node. Will they root if the upper cut is between the nodes? Where will the root form? At the node above the upper cut?
Thanks,
Cheers
NN

 

[leatherback]

Quick question on JM airlyering. I have done plenty with success but I have always try the upper cut at around the node. Will they root if the upper cut is between the nodes? Where will the root form? At the node above the upper cut?
Thanks,
Cheers
NN

The roots grow from the cambium and will push through the bark, as far as I can tell. Thisis also why a slanted cut works to create a slanted nebari.

 

[0soyoung]

Quick question on JM airlyering. I have done plenty with success but I have always try the upper cut at around the node. Will they root if the upper cut is between the nodes? Where will the root form? At the node above the upper cut?
Thanks,
Cheers
NN

Adventitious roots can be grown anywhere (above ground, I say redundantly just for emphasis). It is just a matter of getting the cellular auxin level high enough to cause cambium cells to upregulate to producing even more auxin (just like a root tip does). There are auxin producers in a node (i.e., buds/bud-initials), hence, it is a bit easier to get adventitious rooting at a node compared to an internode.

So, IMHO, if one is air-layering, it doesn't matter where the girdle is cut with regard to the node(s). But, for cuttings, it is advantageous to have a node near the bottom of the cutting.

 

[Mikecheck123]

Adventitious roots can be grown anywhere (above ground, I say redundantly just for emphasis). It is just a matter of getting the cellular auxin level high enough to cause cambium cells to upregulate to producing even more auxin (just like a root tip does). There are auxin producers in a node (i.e., buds/bud-initials), hence, it is a bit easier to get adventitious rooting at a node compared to an internode.

So, IMHO, if one is air-layering, it doesn't matter where the girdle is cut with regard to the node(s). But, for cuttings, it is advantageous to have a node near the bottom of the cutting.

 

[cbroad]

But, for cuttings, it is advantageous to have a node near the bottom of the cutting.

Would you say cut through the node or below the node for the most benefit?

If one is air-layering, it doesn't matter where the girdle is cut with regard to the node(s)

If it's the same mechanism for both air layers and cuttings, shouldn't both have equal chances? Maybe because a cutting is more of a ticking time bomb, so a near the node cut would be more advantageous for success?

 

[Mikecheck123]

Would you say cut through the node or below the node for the most benefit?



If it's the same mechanism for both air layers and cuttings, shouldn't both have equal chances? Maybe because a cutting is more of a ticking time bomb, so a near the node cut would be more advantageous for success?

There's one huge difference: the water supply is disrupted with a cutting, but not with an air layer.

 

[0soyoung]

Would you say cut through the node or below the node for the most benefit?



If it's the same mechanism for both air layers and cuttings, shouldn't both have equal chances? Maybe because a cutting is more of a ticking time bomb, so a near the node cut would be more advantageous for success?

Immediately below - keep the node, itself, intact.

Of course the same is true for a layer. But. with a cutting, it is a race against desiccation (so time is of the essence) whereas there is no such urgency with a layer (it is supplied water via the intact xylem/wood). So, one might say that there is greater freedom in choosing where the first node is with respect to 'the ground' by layering.

BTW, I've noticed (having done it unintentionally/unthinkingly) that Japanese maples can be rooted by simply keeping a (leafless) node damp (i.e., no girdle required). Also, some collectors layer their rare cultivar off the root stock in the same way. It is remarkable to me that this too works, but when it doesn't nothing is lost (as opposed to girdling as one would normally do to ground layer a cultivar off a root stock). Yet, girdling allows one to choose exactly where the adventitious roots may be made to appear.

 

[cbroad]

Immediately below - keep the node, itself, intact

This is how I've been doing it all along, but until recently I thought maybe it either didn't matter or was actually more advantageous to cut above the node.

that Japanese maples can be rooted by simply keeping a (leafless) node damp (i.e., no girdle required)

That sounds like how "banding" works to root very tough species. I haven't ever tried it yet, but thought that could be a viable way to propagate if layering or cuttings won't work.

Thanks for the answers!

 

[Javaman4373]

Question: if you air layer a flowering tree or shrub, should you remove the blossums on the distal part during the air layer?

 

[BrazilianMoistWood]

I have a question in regards to energy balancing with an air layer attached on a brt. Normally you want say one leaf on top, then two on the second branch then three on the third etc etc. (Not actually but figuratively) so you partial defoliate or prune branches to balance or direct energy to one part of the tree. With the air layer, would the tree still recognize the leaves past the severed cambium and send more energy there and potentially “forget” about the rest of the tree if it has 10x the leaf mass?

 

[Forsoothe!]

Great Work!View attachment 139487

Thanks, I needed that.

 

[Ngidm]

Wow. So much info here. Thanks for all the posts. I can't wait to try it this Spring!

--N

 

[hinmo24t]

Prob missed it, but the layer has to be attempted under foliage or branch end? On old droopy maple for instance? Has to be upward above the layer?

 

[leatherback]

Prob missed it, but the layer has to be attempted under foliage or branch end? On old droopy maple for instance? Has to be upward above the layer?

The layer (peeled bark) has to be between the roots and foliage . Whether that foliage is fysically lower than the layer is not that important (Although that branch will be weaker than more vertical branches, thus might be slower in rooting)

 

[hinmo24t]

The layer (peeled bark) has to be between the roots and foliage . Whether that foliage is fysically lower than the layer is not that important (Although that branch will be weaker than more vertical branches, thus might be slower in rooting)

Thanks. I thought roots won't grow if it done inverted and the layer is above the end of branch. Like on a weeping maple if you tried to do a branch layering

I hope you're right becauae my parents old red Acer is so big all the branching are weighed down...so layers would be above end of branches most likely when trying to make roots

Maybe I saw somewhere its only on the bottom of layer it'll drop roots and it's more of a gravity type of thing and not impossible regardless

Thanks again, I'll be going for it on weeping and a big mature tree in spring, on smaller branching

 

[Bonsai Nut]

Thanks. I thought roots won't grow if it done inverted and the layer is above the end of branch. Like on a weeping maple if you tried to do a branch layering

No. This is a weird wives' tale and I have no idea where it originated. Certainly trees can grow roots even if ALL their foliage is below the root level. Think of cascading trees on a cliff, for example.

 

[hinmo24t]

No. This is a weird wives' tale and I have no idea where it originated. Certainly trees can grow roots even if ALL their foliage is below the root level. Think of cascading trees on a cliff, for example.

thank you and awesome because i was thinking id be rejected or on a damn ladder on my parents landscape tree. its a good 30' tall and overgrown, and i want smaller airlayers...

 

[Vali]

Thanks. I thought roots won't grow if it done inverted and the layer is above the end of branch. Like on a weeping maple if you tried to do a branch layering

I had a succesfull layer on prunus cerasifera branch that grew downwards. It had no problem rooting

 

[hinmo24t]

I had a succesfull layer on prunus cerasifera branch that grew downwards. It had no problem rooting

thats good to hear, thanks! !