What's the Deal with A.P. 'Shin deshojo' Layers? Brainstorming Needed.

[0soyoung]

I’m looking for help to figure out why my a.p. Shin deshojo is so difficult to propagate by air layering.


Over the last 7 years or so, I’ve attempted something like 20, give or take, air layers of my a.p. Shin deshojo landscape specimen. Except for a couple of occasions that the girdle was bridged, I’ve always gotten harvestable layers in one season. I’ve always left the sphagnum in place and potted the layer in Turface with the stem secured to a bamboo support pole or two screwed to the wall of the pot so that there would be no movement to damage the roots. The layers have always thrived through the end of the season. The following spring they leaf out and then, around the point of hardening. collapse, regardless of whether left in situ or repotted ‘as buds swell’.


That is, except for one from three years ago (layered/harvested in 2015) that is still going strong and another from the year before last (layered/harvested in 2016) that made it through this past winter and is limping along now after nearly dying last season.


Just yesterday I did a little autopsy of two 2017 layers that just died. This year I’ve noted necrosis (i.e., ‘black’ bark) of the trunk (which just appeared in the last week), just above the root collar or soil line - the bark is still green above. You should see this necrosis in the following pix. The first pair of pix are of the root ‘ball’ popped from the pot and the necrosis on one of the two. The other pair are of the root 'ball' after washing and combing the roots of the other 2017 layer. In both instances I found a (very) few white, growing root tips.

• Lots of roots.
• Thrives.
• Then dies the following spring
  • necrosis at the base of the trunk.

I need ideas of why this is happening.

 

[Shima]

I’ve noted necrosis (i.e., ‘black’ bark) of the trunk

This happened to all layers I did on a large one in the ground. Even though I was very careful about sterilizing tools. After 2 years I gave up.

 

[Alain BERTRAND]

I have verticillium wilt in my backyard. One year after I put dozens of Japanese maples in the ground most of them were affected but did not die, and then the symptoms disappeared. Thus after two or three years, I transplanted some to do root work. Symptoms reappeared. So I guess that when the tree is strong it can fight the disease but after it has weaken, it can't. Could explain your troubles. Could you show transverse cuts of the trunk ?

 

[0soyoung]

Sequence of three pruning cross-sections progressing downward, right to left (left = closest to roots).



Transverse section of the left (closest to roots) piece.

 

[Alain BERTRAND]

At least, this is not verticillium wilt. Sorry for not being able to help more.

 

[just.wing.it]

Maybe a dumb question, but are you using any type of wire around the gridle, a tourniquet??

 

[KiwiPlantGuy]

Sequence of three pruning cross-sections progressing downward, right to left (left = closest to roots).

View attachment 190644

Transverse section of the left (closest to roots) piece.
View attachment 190645

Hi 0soyoung,
I too have had a few airlayer failures on Shindeshojo JM. But mine don’t even grow roots, just go brown around the girdle area and top of that branch collapses. I amwondering if my technique is wrong and the girdle area is too wet, but with yours getting roots and then failing in the following spring is weird. I am thinking along same lines as others suggesting that the health of the airlayered tree has been compromised sometime)
Can you either treat tree with Hydrogen Peroxide (drench) or spray in the previous Autumn with a systemic fungicide (Cleary’s stuff?? - Thiophanate Methyl - Topsin in my country) to kill off Xylem/Phloem based pathogens.
I am just pondering as I don’t really know the answer.
Charles

 

[M. Frary]

It almost sounds like a soil problem.
Is the turface holding so much moisture the tender new roots don't want to go out in the world and explore? Harden up in time for winter?
Maybe a little dryer mix so the really need to search and get big the first growing season.
I've only layered elms so my guess is that,just a guess. They will grow new roots so easy.

 

[0soyoung]

Hi 0soyoung,
I too have had a few airlayer failures on Shindeshojo JM. But mine don’t even grow roots, just go brown around the girdle area and top of that branch collapses. I amwondering if my technique is wrong and the girdle area is too wet, but with yours getting roots and then failing in the following spring is weird. I am thinking along same lines as others suggesting that the health of the airlayered tree has been compromised sometime)

I have a similar problem with layering a.p. "Higasayama". The cambium just below the bottom of the girdle dies and causes the xylem to get clogged (CODIT reaction). I then get to watch the leaves of the attached layer turn brown from the bottom of the stem to the top over the course of 2 to 4 days. I understand this as a limited capacity for the phloem of the variety to carry auxin upward to the bottom edge of the girdle.

My shin deshojo problem corresponds to what was the top of the girdle. Are you saying your shin deshojo is like my 'Higasama' or that your shin deshojo layer cambium, immediately above the girdle, dies while on the tree?

Can you either treat tree with Hydrogen Peroxide (drench) or spray in the previous Autumn with a systemic fungicide (Cleary’s stuff?? - Thiophanate Methyl - Topsin in my country) to kill off Xylem/Phloem based pathogens.
I am just pondering as I don’t really know the answer.
Charles

Good ideas. Thanks.
I really don't know the answer either (and it is pissing me off )

If it is pathogen caused, it doesn't seem to be communicable:
The 2015 layer was repotted with two smaller 2015 layers in the spring of 2016. The two smaller ones died fairly soon afterward. Meanwhile I made another 9 layers from the mother landscape specimen in 2016. They were harvested and overwintered in my standard fashion. I arranged 7 of them and the 2015 survivor as a forest planting in a large tray. The 7 died and the 2015 survivor (seemingly?) continues to thrive. The extra 2 small layers were not repotted. It is one of these that is limping, but still the alive this season; the other also died.

 

[0soyoung]

It almost sounds like a soil problem.
Is the turface holding so much moisture the tender new roots don't want to go out in the world and explore? Harden up in time for winter?
Maybe a little dryer mix so the really need to search and get big the first growing season.
I've only layered elms so my guess is that,just a guess. They will grow new roots so easy.

Oops, I didn't provide any sense of scale for the root photos. Those root 'balls' are the bottom half of 5 gallon pots. The combed out roots spread over more than 12 inches. So they did go out into the world and did explore after the layer was harvested.

But you do raise a good point about winter moisture. Ever since I broke all the roots off a newly harvested air layer trying to get rid of the sphagnum, it has been my habit to leave the sphagnum in place for the first winter. It doesn't cause any problems with other varieties and species, but maybe it keeps things too wet for shin deshojo.
Thanks.

 

[River's Edge]

I’m looking for help to figure out why my a.p. Shin deshojo is so difficult to propagate by air layering.


Over the last 7 years or so, I’ve attempted something like 20, give or take, air layers of my a.p. Shin deshojo landscape specimen. Except for a couple of occasions that the girdle was bridged, I’ve always gotten harvestable layers in one season. I’ve always left the sphagnum in place and potted the layer in Turface with the stem secured to a bamboo support pole or two screwed to the wall of the pot so that there would be no movement to damage the roots. The layers have always thrived through the end of the season. The following spring they leaf out and then, around the point of hardening. collapse, regardless of whether left in situ or repotted ‘as buds swell’.


That is, except for one from three years ago (layered/harvested in 2015) that is still going strong and another from the year before last (layered/harvested in 2016) that made it through this past winter and is limping along now after nearly dying last season.


Just yesterday I did a little autopsy of two 2017 layers that just died. This year I’ve noted necrosis (i.e., ‘black’ bark) of the trunk (which just appeared in the last week), just above the root collar or soil line - the bark is still green above. You should see this necrosis in the following pix. The first pair of pix are of the root ‘ball’ popped from the pot and the necrosis on one of the two. The other pair are of the root 'ball' after washing and combing the roots of the other 2017 layer. In both instances I found a (very) few white, growing root tips.

View attachment 190638View attachment 190639View attachment 190640View attachment 190641

• Lots of roots.
• Thrives.
• Then dies the following spring
  • necrosis at the base of the trunk.

I need ideas of why this is happening.

I am sure that you are pretty careful with each aspect based on your posts and descriptions. Therefore i would look for a simpler solution. The sphagnum left on through the winter would retain a lot more moisture in close. Our Pacific North West winters can be very damp as well. Maples are notorious for winter issues if too much water is retained around the roots even in light freeze conditions with roots bursting.
Try everything the same except for teasing out the sphagnum when transferring the air layer to the first repot. One other suggestion would be to change particle size of components to slightly larger allowing more aeration and drainage, just in case excess moisture retention is contributing. I had a similar problem with a coral bark maple and i felt that leaving the finely chopped sphagnum and fine pumice around after separation contributed to the problem. The next time I was successful when i removed as much as possible with a gentle rinse and worked in larger particles.
Not sure if this is the answer but it might help.

 

[0soyoung]

Maybe a dumb question, but are you using any type of wire around the gridle, a tourniquet??

No, no tourniquet.

BTW, there are no 'dumb questions'.

 

[KiwiPlantGuy]

I have a similar problem with layering a.p. "Higasayama". The cambium just below the bottom of the girdle dies and causes the xylem to get clogged (CODIT reaction). I then get to watch the leaves of the attached layer turn brown from the bottom of the stem to the top over the course of 2 to 4 days. I understand this as a limited capacity for the phloem of the variety to carry auxin upward to the bottom edge of the girdle.

My shin deshojo problem corresponds to what was the top of the girdle. Are you saying your shin deshojo is like my 'Higasama' or that your shin deshojo layer cambium, immediately above the girdle, dies while on the tree?

Good ideas. Thanks.
I really don't know the answer either (and it is pissing me off )

If it is pathogen caused, it doesn't seem to be communicable:
The 2015 layer was repotted with two smaller 2015 layers in the spring of 2016. The two smaller ones died fairly soon afterward. Meanwhile I made another 9 layers from the mother landscape specimen in 2016. They were harvested and overwintered in my standard fashion. I arranged 7 of them and the 2015 survivor as a forest planting in a large tray. The 7 died and the 2015 survivor (seemingly?) continues to thrive. The extra 2 small layers were not repotted. It is one of these that is limping, but still the alive this season; the other also died.

Hi 0soyoung,

I think the cambium at the bottom of the girdle goes brown (and I watched the slow dying days to collapse ). Opposite of your Shindeshojo layers that root fine.
My other pondering is that - have you tried “bonsai soil” as your media for the layers? I used 2 split 3 litre pots and string to hold together(one split on one side and other side for other pot). This avoids the spagnum moss difficulties that others (@Riversedgebonsai ) have highlighted. And nothing wrong with adding spagnum on top of your inorganic soil to slow the evaporation etc.
I guess you know this and have been successful (re forest), doing cuttings. My minor success recently has a 3/25 rooting success using 1% IBA. I am going to try a load of cuttings next season at 2% IBA to get better percentages. Longer wait time for trunk size, and no difference in trunk girths this way.
Very happy to follow on this thread as I am pondering buying another Shindeshojo to try more air-layers, and I hope you find some answers to the thorny issue.
Charles

 

[ajm55555]

Maples are notorious for winter issues if too much water is retained around the roots even in light freeze conditions with roots bursting.

I'm pretty sure that's what happened to my Deshojo.
I saw these signs that something was not good with the roots this spring:

• many dead branches
• most of the buds looked dry and would not swell
• darker spots on the main trunk better visible when the drunk was wet

When I repotted it, trying to save it, I found a lot of dead roots. We didn't have a particularly cold winter (last year's was much colder) but I think the combination of too much moisture and cold eventually killed it.

 

[R3x]

Just my $0,002 from Ryan Neil's Bonsai Mirai stream on airlayering: he says to separate deciduous air layers next season in the spring before the buds open (when they swell). Also said he has never had any frost damage on new roots on air layers - there was some explanation to that. So maybe try to wait till spring next time.

 

[River's Edge]

Hi 0soyoung,

I think the cambium at the bottom of the girdle goes brown (and I watched the slow dying days to collapse ). Opposite of your Shindeshojo layers that root fine.
My other pondering is that - have you tried “bonsai soil” as your media for the layers? I used 2 split 3 litre pots and string to hold together(one split on one side and other side for other pot). This avoids the spagnum moss difficulties that others (@Riversedgebonsai ) have highlighted. And nothing wrong with adding spagnum on top of your inorganic soil to slow the evaporation etc.
I guess you know this and have been successful (re forest), doing cuttings. My minor success recently has a 3/25 rooting success using 1% IBA. I am going to try a load of cuttings next season at 2% IBA to get better percentages. Longer wait time for trunk size, and no difference in trunk girths this way.
Very happy to follow on this thread as I am pondering buying another Shindeshojo to try more air-layers, and I hope you find some answers to the thorny issue.
Charles

If i could add several thoughts for consideration.
1. I avoided mentioning particular soil components simply because it causes a distraction. The key is to promote aerobic conditions rather than anaerobic conditions around the new roots when transplanted ( i do favour inorganic). So if particle size, structure,hardness and shape is considered many components can work well. The sphagnum remaining after several months will have lost its efficacy in anti-bacterial properties and will be decomposing. I think that is a key contributing factor down the road.
For air layer process itself key aspects from my point of view.
- I prefer the gel and i find it more effective to let it sit on the fresh cut for a few moments before packing. I think this allows the fresh cut cells to absorb small amounts before it is diluted or pushed off by the moist medium packed around the cut. Also because it is a gel, it does not dry out the cut while i wait for a few moments.
-When an air layer has been removed and freshly transplanted, they do better when the roots are initially planted deeper than normal, with a good cover above. 1 1/2 inches to 2 inches below the soil surface with shredded sphagnum on the surface temporarily.
-Osoyoung mentioned the importance of anchoring the transplant securely and that is very important, leaving the longer stub below the ring of roots until the first repot is of great assistance in this as well.
- extra winter protection the first year after separation.

 

[thumblessprimate1]

Maybe there is something already in the mother plant, but because the mother plant is strong it keeps going. The air layer stays weak and dies.

 

[0soyoung]

- have you tried “bonsai soil” as your media for the layers? I used 2 split 3 litre pots and string to hold together(one split on one side and other side for other pot).

Indeed I have. It is my preferred way, but I've never figured out a way to affect it on a horizontal branch. My layers are of horizontal-ish branches, so ...

I guess you know this and have been successful (re forest), doing cuttings. My minor success recently has a 3/25 rooting success using 1% IBA. I am going to try a load of cuttings next season at 2% IBA to get better percentages. Longer wait time for trunk size, and no difference in trunk girths this way.

I've tried several times without success, but I doubt I've struck 25 shin deshojo cuttings. I only used 0.3% IBA. This is interesting enough to motivate me to try again. Leaves are small enough to make entertaining minis if nothing else.

 

[0soyoung]

Maybe there is something already in the mother plant, but because the mother plant is strong it keeps going. The air layer stays weak and dies.

You mean something like a 'weak on its own roots' gene?

It is a reasonable thought that you have. In my early attempts, 6 or 7 years ago, I attributed it to the weather as all the shin deshojos in the garden nurseries looked sickly that same year. I recall trying again the following year but with the same results. I gave up on shin deshojo and moved on to focus on layering a.p. 'Higasayama', stewartia, JBP, katsura (cercidiphyllum), red maple, and (I forget what else). 'Higasayama' has always failed to layer. Otherwise I am a genius! Oh, and shin deshojo

 

[thumblessprimate1]

No

You mean something like a 'weak on its own roots' gene?

It is a reasonable thought that you have. In my early attempts, 6 or 7 years ago, I attributed it to the weather as all the shin deshojos in the garden nurseries looked sickly that same year. I recall trying again the following year but with the same results. I gave up on shin deshojo and moved on to focus on layering a.p. 'Higasayama', stewartia, JBP, katsura (cercidiphyllum), red maple, and (I forget what else). 'Higasayama' has always failed to layer. Otherwise I am a genius! Oh, and shin deshojo

No. I think perhaps the mother tree lived with the disease. Sort of like a relatively healthy person living with the bacteria that causes tuberculosis. But when weakened, the bacteria prevails. So an airlayer might eventually die from losing its fight. I have a few shin Deshojo airlayers. One I still have, while the others sold. It is not strong so I ledft it to grow freely. This year is looking better.