Oak air layer

[treepirate]

I know we have had a number of threads on this but I wanted to see if we can puzzle this out.
If anyone has any new information or tried any new techniques then please feel free to post.

The oak we generally have in the UK is Quercus robur, the common or english oak.

A tricky creature to collect as yamadori, a fickle creature to repot and a tree that can take a couple of years to die after both events.

I know that the air layer technique with sphagnum will produce roots.
I've seen 5 inch trees be air layered with a good number of roots then just fade out once sepetated.
It often calluses up and needs recut.
The slow callusing and root growth will mean separation in the following year minimum as with some species like the hawthorn.

I'm thinking of a number of different things to try to overcome this.
If any one has tried any please post your results.

1- leaving the airlayer on for 3 years before separation.

2- leaving the airlayer on 2 years then repotting into akadama while still attached and leaving it on possibly another 1 or 2 year before separation.

 

[Shibui]

I'm still batting 100% for collected English oak but maybe I'm not trying hard enough. Most have been younger trees.
Word here is that oaks in general do better with removing less roots at repotting but doing it more often which tallies with my experience of them sulking for a year after heavy root pruning though I have not had any die as a result.

Can't help with the layering as I have not had to do that to any.

 

[Lutonian]

I have had good success with collecting and repotting querus robur when the first flush has extended but not fully hardened off.

 

[treepirate]

Anyone had multiple success collecting any other times of year?

 

[Lutonian]

Anyone had multiple success collecting any other times of year?

No I stick to the timing that works for me

 

[Wires_Guy_wires]

Anyone had multiple success collecting any other times of year?

Summer: 6 out of 6 Q robur died. 2/2 Q ilex died. 1/1 Q suber died.
Spring before bud swelling: 4/4 Q robur survived. 3/3 Q ilex survived.
Small sample pool, but it made clear to me that the general consensus of summer collection isn't right for me.

I too have no experience with air layering oaks. But if they hate summer root work and we separate the layer in summer, I'm thinking 1+1=2.
Leaving it until after winter and cutting it in spring might be a better idea. However, I'm very interested in the long term effects of a cut site standing in bonsai soil after separation. The fatter your air layer, the more open-ended wood will end up on a substrate while it hasn't healed yet, it might even never heal. I believe this can contribute to a failure. And it makes sense too.. All of my oaks with root damage died rather quickly, within a month or two. If it slowly succumbs over the course of years, it might not be the root work, but the wide open wound sitting in a bonsai pot.

 

[treepirate]

I totally agree this summer collection thing that seems to be going around from a UK site didn't work for me.
All mine were 3 inch minimum width but lost 6 of 7 trees and days of hard sweat digging in the heat.

With the sap flow being so slow in oak, waiting till first flush is well out, or just hardened off is a better time as the old diesel engine of the quercus will be plodding away by then.

 

[treepirate]

Big open cut on bottom is definitely a problem too.
We all know waiting for oak wounds to roll in takes years.
So this has to be considered when separating the air layer-possibly the reason the separation fails slowly over the course of time.

 

[treepirate]

I have read some in depth reports from back in the 1960s about layering, seedlings and grafting on oaks and other hardwoods and even under specialists it's a tough thing to produce.
They state that the different sub species of oak make a huge difference.

The big thing is... It can 100% be done...
I believe we can work it out.

I know from his website Ian from Bonsai Eeijit has had success, not sure if he is on here?

 

[RobC]

how about air layer + approach graft? i have no experience on this. i just recently saw this on YouTube.

 

[BrianBay9]

I've tried a couple of air layers and ground layers on coast live oak. Got minimal new roots, but separated anyway and they're still going. But, this is a species that you can collect with virtually no feeder roots. They seem to survive as big cuttings. They may be unique among the Quercus species.

 

[treepirate]

how about air layer + approach graft? i have no experience on this. i just recently saw this on YouTube.

View attachment 354139

I've been considering this possibility for a while...
Maybe get 9 approach grafts to take for a year or two maybe a way forward.
I think it will also difficult to get these to take as of the slow water mobility.
Theoreticaly Im not sure if the tree would push roots out below the ring of root grafts as the veins above each graft will be feeding directly above. Possibly it may push roots out in between the grafts depending on how the oak moves water lateraly.

If anyone with any botanical knowledge can add to this??

 

[Attmos]

Summer: 6 out of 6 Q robur died. 2/2 Q ilex died. 1/1 Q suber died.
Spring before bud swelling: 4/4 Q robur survived. 3/3 Q ilex survived.
Small sample pool, but it made clear to me that the general consensus of summer collection isn't right for me.

I too have no experience with air layering oaks. But if they hate summer root work and we separate the layer in summer, I'm thinking 1+1=2.
Leaving it until after winter and cutting it in spring might be a better idea. However, I'm very interested in the long term effects of a cut site standing in bonsai soil after separation. The fatter your air layer, the more open-ended wood will end up on a substrate while it hasn't healed yet, it might even never heal. I believe this can contribute to a failure. And it makes sense too.. All of my oaks with root damage died rather quickly, within a month or two. If it slowly succumbs over the course of years, it might not be the root work, but the wide open wound sitting in a bonsai pot.

Think it could be possible to support the limb you're air-layering, and then cut the hardwood while it's still attached by the roots to the mother tree?

It would be a lot like doing open heart surgery, lol, and you would have to separate some of the new roots..... Anyway, the cut end could then be left to callus before separating from the mother.