Failed air layer ?

[Kingpoutine]

I did 3 air layers on a crabapple in my yard today I opened one because it’s more then 2 months and no roots were visable….. opened it and I donno wtf is happening here…..

 

[Bonsai & Bourbon]

I tried several air layerings this spring and my cherries had the exact look. I'm pretty sure that is better than just having nothing going on at all. I'm going to try again next year.

 

[MrWunderful]

What medium did you use?

 

[Bonsai & Bourbon]

two parts sphagnum moss and one part vermiculite. We had a cold spell after a warm initial spring. I think that was the problem.

 

[NaoTK]

It clearly bridged, that's all. Just re-cut the lower side of the gap and make the gap to the upper side wider, there's still plenty of time this year. The rule of thumb is 3-5x the diameter.

 

[0soyoung]

That is growth known as callus. It always happens in this circumstance (layering) and generally precedes root formation. On the other hand, the formation of adventitious roots is not a sure thing. Some species simply won't do it. Also it frequently happens that trees that have achieved flowering/fruiting competence will no longer root.

In your pic, it appears that the callus on top may be connected with the callus below. If so, this 'bridging' of the girdle is a path for the auxin to continue down the tree. Since the accumulation of auxin is key to forming root tips, bridging is often the cause of ruin.

I suggest you cut off the callus below and remove any callus on the bare wood. Leave the upper callus alone as part of the de-differentiation of cells that is a precursor for roots has already been done (removing it and you start the whole process over again from ground zero).

 

[Kingpoutine]

I used sphagnum moss. I only opened one but I’m guessing that my other ones have the same look on the inside.

it has been 2 months is there any reason to leave it longer in hopes of it rooting or just I just open it and clean it up and try again ?

 

[NaoTK]

It will absolutely not root out once it has bridged

 

[Shibui]

A layer can still root after the callus has bridged but there is now a connection to the roots so not the same incentive to root and many just concentrate on healing the gap rather than making new roots so lots just don't root after this. Many species don't even need the girdle to root as a layer.
It is possible the original cut was not cleaned well enough. Remnants of cambium on the girdled wood help callus growth to bridge the gap.
You can still clean out the bridge, extend the girdle down a bit further so it won't bridge again and replace the sphagnum and wrapping. Rooting should be quicker now that the tree already has good callus.
A loop of copper wire tied tight under the top cut can help prevent bridging.

Not sure what effect your cool winters will have on layers left on over winter or on layers transplanted just before winter. Has anyone had direct experience with layers through winter up there?

 

[Kingpoutine]

A layer can still root after the callus has bridged but there is now a connection to the roots so not the same incentive to root and many just concentrate on healing the gap rather than making new roots so lots just don't root after this. Many species don't even need the girdle to root as a layer.
It is possible the original cut was not cleaned well enough. Remnants of cambium on the girdled wood help callus growth to bridge the gap.
You can still clean out the bridge, extend the girdle down a bit further so it won't bridge again and replace the sphagnum and wrapping. Rooting should be quicker now that the tree already has good callus.
A loop of copper wire tied tight under the top cut can help prevent bridging.

Not sure what effect your cool winters will have on layers left on over winter or on layers transplanted just before winter. Has anyone had direct experience with layers through winter up there?

I store most of my trees in a heated garage at 3*c over the winter. But I have seen local people air layer apples and store them unheated in the ground or in unheated buildings.

 

[WNC Bonsai]

My Chinese elm callused over but did not bridge so yesterday I scraped the bare wood again, dusted the callus with hormone and wrapped it back up. I was surprised since my slippery elm has made tons of roots in just over a month. But the foliage is growing like crazy so it should still root.