Structural Pruning of Japanese Maples

[leatherback]

Please know that I didn't mean to point out the wording thing.

I know. There is however no worse advice than advice using the wrong words and with that, being misunderstood. Using the right words is sometimes quite crucial

 

[Ayxowpat]

There is, of course, some expenditure of energy in each bud.
It isn't until the leaves are 'hardened' that they contribute energy (carbohydrates) to the tree; prior they are energy (carbohydrate) consumers.

Firstly, thanks for all the valuable information you all provided.

When does a leaf produce the whole energy it consumed for growing? I know it depends on many factors, however what I am trying to understand is: does a growing little tiny green sprout of leaf start photosynthesis as it gets the green color or does it wait until hardening?

Another question, in terms of light pruning, what would be the exact timing to prune a branch considering it produced as much as it consumed? I am trying to figure out 'wasted energy is regained' situation.

 

[leatherback]

does a growing little tiny green sprout of leaf start photosynthesis as it gets the green color or does it wait until hardening?

Green = chlorophyll = photosynthesis machines. As soon as you can see green, the green can capture sun's energy and start helping with sugar production.

 

[0soyoung]

When does a leaf produce the whole energy it consumed for growing? I know it depends on many factors, however what I am trying to understand is: does a growing little tiny green sprout of leaf start photosynthesis as it gets the green color or does it wait until hardening?

The photocenters that power photosynthesis have to be built in the emerging leaf, in presence of light. The green coloration gets darker as more photocenters are created and the net rate of photosynthesis must correspondingly ramp up, but I cannot say exactly when a leaf crosses the line to being a net energy producer. I'm just sure that it is in this state (of being a net energy producer) when the leaf is flat or 'hardened'.

The red color of red leafed varieties comes from anthocyanins that are in a layer of leaf tissue above the photocenters. Their function is to shade the photocenters from sunlight. If you have the leaves emerge in shade, say, the photosynthetic apparatus will be 'shade adapted'. If you then move the tree into full sun, the leaves will get a darker muddy red coloration because anthocyanins are produced to keep the intense sunlight damage. Many red leafed varieties have a similar dark red coloration normally, but it tends to fade if the leaf is shaded - the anthocyanins get removed to uncover the underlying chlorophyll green. My point is only that seeing a dark green leaf color generally works, but color alone isn't a reliable criterion. The concept is basically correct, but it is the presentation of flat, mature leaf is more reliable criterion.

Another question, in terms of light pruning, what would be the exact timing to prune a branch considering it produced as much as it consumed? I am trying to figure out 'wasted energy is regained' situation.

Trees are made of the same stuff that produces and uses as 'energy' - elementary sugars. In scientific studies, the dry weight of trees is used as the energy metric. This kind of measurement is literally a dead end. In bonsai practice, though, we are wanting stem thickening when we fret about 'energy', I think. Maximal energy utilization, in this sense, occurs if one simply lets it grow'. Specifically, letting a branch run all season will thicken the branch most rapidly. It is simply a matter of maximal leaf area and auxin production, as well as exposure to sunlight (energy input).

You could do a bit of scientific study yourself by choosing to lop off all of a season's growth, measuring the dry weight of what you lop off and also measuring the thickness change of the base branch. I think you will find that letting the branch grow all season produces the most dry weight in what is pruned off (versus say the total dry weight of multiple prunings during the season) as well as the most gain in the caliper of the base branch.

Thickening is driven by the flow of carbohydrate and auxin down the stem. When the new growth is extending, auxin is being consumed locally to affect elongation of the new cells. As the branch gets longer, a progressively lower fraction of the auxin is consumed locally and so more goes down the stem stimulating cambium cell division and consumption of sugars supplied via the phloem = making the stem thicken. Every time you prune, you reset this process and so, 'waste energy'.

An extreme version is pinching or removing the tip when it is soft. This removes the dominant auxin producer. Hence growth tends to just stop until a remnant bud at the base of a leaf is released (which can be as long as a sizable fraction of the growing season). People use this as a maintenance technique because they don't want their maple canopy to get larger and they don't want their branches to thicken. Energy isn't being wasted, per se, because little is being produced. However the vitality of a tree kept in this state can decline markedly over the span of a few seasons (there is not quite enough auxin to affect root growth which, in turn, means lower levels of cytokinins are produced to release buds, etc.).

yadda yadda yadda

 

[sorce]

I am trying to figure out 'wasted energy is regained' situation.

Don't forget to account for the additional energy needed on the back end. Energy to heal pruning cuts. Lost future energy. Energy to grow anew.

This is why I just chose to prune as close to right before growth begins as possible.

Before Spring growth, before Summer growth, and right before the subtle moon cycles with species that grow continuously.

That will ensure you utilized everything possible.

Sorce

 

[hinmo24t]

this thread was a lot to digest.


i have a deshosho i believe that is an air layer...the one on the ground
watch a youtuber from washington that did some structure pruning in fall
mine still actually has most its leafs unlike some other maples i have that have very few now

i was going to move this maple to cold garage soon, in a week or two,
and was wondering it you think itd be advised to do some branch pruning (no hard cuts of the trunk) just branch selection?


thoughts? i could wait until spring too

was even tihnking of repotting and taking it down to 5 or 6" and restarting there
but rethinking that now and might be able to find something in branch selection now, root work and repot in spring. it doesnt have super low branching...some lower buds i do see on it popping pink noses out of trunk

@thatbonsaiguydb


while at it, okay time of year to do a little wiring on the trident? lower left



thanks,
Tom

 

[hinmo24t]

Here it is now...think I can promote soma taper w rootwork repot

 

[clem]

hi, i think it is ok to trim (if you let some buds on the branches to attact sapp and avoid sapp withdraw in winter) but not the good time to repot. It is better/safer to repot in spring (the best moment IMO) or in the end of Augsut/beginning of september. As Ryan says : "As a pro, i want to have a 100% success technic, so, if the spring repotting is a 100% success period, why should i take risks and repot at another season ?"

The best time to wire is autumn as Ryan says, because the tree developps its vascular tissues and drops its leaves.
I like very much to wire during spring or summer when a maple developps new shoots because the new shoots are still very flexible (you can make some irregular curves) and the position is hold in 2 weeks. If you wire when the tree is growing, it is very important to watch out the branch recently wired in a daily basis and remove the wire early enough to avoid "wire scars"..

 

[hinmo24t]

hi, i think it is ok to trim (if you let some buds on the branches to attact sapp and avoid sapp withdraw in winter) but not the good time to repot. It is better/safer to repot in spring (the best moment IMO) or in the end of Augsut/beginning of september. As Ryan says : "As a pro, i want to have a 100% success technic, so, if the spring repotting is a 100% success period, why should i take risks and repot at another season ?"

The best time to wire is autumn as Ryan says, because the tree developps its vascular tissues and drops its leaves.
I like very much to wire during spring or summer when a maple developps new shoots because the new shoots are still very flexible (you can make some irregular curves) and the position is hold in 2 weeks. If you wire when the tree is growing, it is very important to watch out the branch recently wired in a daily basis and remove the wire early enough to avoid "wire scars"..

Thanks @clem
I wrote confusing - I won't repot w rootwork until spring. Good to know you suggest I could select some branches soon, keeping in mind buds. As for wiring, thanks for info, I won't mind clip and grow for the maples either so I'll keep it in mind because I don't want to overlook something and deal w scarring on them or even snapping them...well see and thanks again

You like the size of the tree or idea of brining it down to 5" and start from there? I almost like it now its growing on my. Maybe just focus on taper w good root work and soil/repotting

 

[clem]

ok, fine you'll repot in spring

Your tree could become an "hokidachi" later (broom style). here is a good inspiratrion pic from Hideki Fuse ->


In spring, when you repot, you can choose the best front (with the best nebari and a straight trunk without any scar if possible) and eventually decide to reduce its height. It's up to you to decide if you prefer to reduce its height or not but you need, before to take any decision, to choose the front first.. When you know what is the best front, you can decide if it is better to cut a useless branch on the front for example, or to reduce its height (etc.). You can developp its tapper later with sacrifice branches if you have some on the back (or the side) of the trunk, IMO.

If the nebari isn't good, you can decide to air layer the trunk too !

 

[hinmo24t]

ok, fine you'll repot in spring

Your tree could become an "hokidachi" later (broom style). here is a good inspiratrion pic from Hideki Fuse ->
View attachment 408644

In spring, when you repot, you can choose the best front (with the best nebari and a straight trunk without any scar if possible) and eventually decide to reduce its height. It's up to you to decide if you prefer to reduce its height or not but you need, before to take any decision, to choose the front first.. When you know what is the best front, you can decide if it is better to cut a useless branch on the front for example, or to reduce its height (etc.). You can developp its tapper later with sacrifice branches if you have some on the back (or the side) of the trunk, IMO.

If the nebari isn't good, you can decide to air layer the trunk too !

Good point on layering it...hmm layering an air layer haha. It does have a scar down low

Thanks for the info @clem appreciate it and your trees are awesome

 

[hinmo24t]

@clem you might have inspired me to try a ground layer on this thang! thanks again, at work and got to absorb your post more. there is a significant scar on the bottom of it...i wonder if its a problem to make layer right where a scar is. looks like enough room in pot pictured to build up soil around a layer (with addition of a yogurt cup or something, i might just go for it, ill leave all the foliage on it to support the layer

 

[clem]

Do you know how to make an air layer ? if yes, i think it would be the best to air layer here (on this virtual) to make a shorter tree with better tapper, a "sokan" ->


If you are not at all into air layering, if the nebari of your tree is nice, you can keep it and, for example build a formal upright style. On this project, the weak point is the lack of tapper of the trunk and the lack of branches, but you can make 1 (or more) thread graft (i did some this spring and it isn't difficult) with a branche of your tree (virtual on the right) that you let grow next year (thread graft in spring in 2 years) ->


Show us pics of your tree next spring, after repotting, with the nebari and trunk line clearly visible and we'll give you some advises

 

[hinmo24t]

Do you know how to make an air layer ? if yes, i think it would be the best to air layer here (on this virtual) to make a shorter tree with better tapper, a "sokan" ->
View attachment 408806

If you are not at all into air layering, if the nebari of your tree is nice, you can keep it and, for example build a formal upright style. On this project, the weak point is the lack of tapper of the trunk and the lack of branches, but you can make 1 (or more) thread graft (i did some this spring and it isn't difficult) with a branche of your tree (virtual on the right) that you let grow next year (thread graft in spring in 2 years) ->
View attachment 408807

Show us pics of your tree next spring, after repotting, with the nebari and trunk line clearly visible and we'll give you some advises

Thats interesting and thanks for your time with response. I do air layers and will try your advice and make it above the scar close to where your horizontal layer mark is. In fact I ordered nice sphagnum moss yesterday for a bunch of airlayers in early spring, now including this one.. Thanks again @clem - tom

 

[Kokosunica]

gracias por este hilo.
Me encanta que haya diferentes pensamientos, eso es síntoma de lo que piensas.
Me animaron a hacer una poda radical con poda de raíz hace 1 semana y no ha sangrado nada. Está resguardado en el invernadero
, solo necesita brotar en primavera, pero no lo dudo.
Lo siento por mi ingles. es de un traductor

 

[Brian Van Fleet]

gracias por este hilo.
Me encanta que haya diferentes pensamientos, eso es síntoma de lo que piensas.
Me animaron a hacer una poda radical con poda de raíz hace 1 semana y no ha sangrado nada. Está resguardado en el invernadero
, solo necesita brotar en primavera, pero no lo dudo.
Lo siento por mi ingles. es de un traductor
View attachment 411370
View attachment 411371

I’d say you have effectively pruned away all the structure. I’m not sure why you chose to leave the swollen area. Since you cut so short anyway, it may have been better to cut below the swollen area.

Big chops are best done in the summer when the tree is actively growing.

If it lives, it will be best to select one shoot to be the new leader in the spring, and then leave it alone for a couple years.

 

[Kokosunica]

I’d say you have effectively pruned away all the structure. I’m not sure why you chose to leave the swollen area. Since you cut so short anyway, it may have been better to cut below the swollen area.

Big chops are best done in the summer when the tree is actively growing.

If it lives, it will be best to select one shoot to be the new leader in the spring, and then leave it alone for a couple years.

I decided to cut there because I saw sprouts underneath
I was afraid not to leave sprouts

 

[SeanS]

I’d say you have effectively pruned away all the structure. I’m not sure why you chose to leave the swollen area. Since you cut so short anyway, it may have been better to cut below the swollen area.

Big chops are best done in the summer when the tree is actively growing.

If it lives, it will be best to select one shoot to be the new leader in the spring, and then leave it alone for a couple years.

If you look at the first photo the woollen area is a graft. He’s pruned away all of the cultivar

 

[Brian Van Fleet]

If you look at the first photo the woollen area is a graft. He’s pruned away all of the cultivar

Yeah, I saw that too. Just didn’t want to complicate a message to be potentially lost in translation.

 

[Kokosunica]

parece un injerto. ¡pero no es!
my dog ate the graft years ago and left the maple at ground level.