[red/acer rubrum/swamp-maple] Any tips on pruning a vigorous specimen **to avoid** excessive back-budding?

[SU2]

I have been plagued by this with my few red/swamp maples, the idea was "After collection, let the branches run&grow until thick-enough, then cut to 2 nodes/branch, grow those out and prune them back once thick-enough; repeat til skeleton is achieved, then transition to 'shape/hedge trim' pruning techniques"

This works with almost any (broadleaf deciduous) tree I know of...but with the Maples, I can cut-back a 0.7" thick primary to its lowest single node, and it will still burst several (or a dozen) new buds on that lil remaining stump & on the collar of the stump (usually prunings will also induce trunk-budding, but at minimum all branch collars and branches go into "hyper budding" mode to a degree I simply cannot keep up with and the next thing I know I go out and find 'knuckles' (ie 3+ new vigorous branches growing from the edge of the pruned branch) with half a dozen+ wimpy backbudded shoots on the lower/collar portions of the cut branch..

I can't just let them run & grow forever lol Their "skeletons" are basically achieved, wanna go towards 'refinement' after this next/current intervention here (they are currently *bushes*, badly needing cuts to even fit into their new locations in my "rebuilt nursery", although that's not me doing this early they needed this last fall I just never got to it and it certainly can't wait til this winter as I've got 4'+ branches that are originating from primaries with nearly-90deg bends, good winds will rip them off in the upcoming stormy-season without a doubt so they need pruning, am just loathe to see the 10X backbudding that I can't keep-up with rubbing-off and don't know any tricks (can only imagine how bad it'd be if I tip-pinched, not that it's an option but imagine I'd have over a hundred backbuds if I did that...and I already prune about as aggressively as possible and even that is still an unmanageable amount of backbudding...I have done such prunes both with, and w/o, corresponding root-prunes, I should note this specie handles root-pruning better than almost anything I've seen except ficus.m's!)

Thanks for any advice working these swamp-maples!! Really stoked to start showing-off their gnarly trunks now that the 'skeletons' are about there, but not trying to make topiary/bushes here and that's what I'll get if I do my usual prune and then ignore it like I probably will!(new job/business is taking most of my time and have even lost / killed trees for the 1st time ever I mean not 'i've never lost a tree' but I mean losing bougainvilleas to underwatering, that's never happened til this year!)

 

[Forsoothe!]

That's a pretty good description of why some trees are more adaptable to bonsai than others, and especially why big trees don't make it.

 

[0soyoung]

With any species, anytime you've got buds emerging (in spring or after a cutback/defoliation), simply rub off the ones you don't want.. One can avoid knots/knobs doing this instead of waiting until after the buds have released a new shoot.

Also, don't cut until after leaf drop or just as buds swell. 'Letting them run' during the growing season gives the maximum thickening for the year. You can tune the relative strengths with partial or full defoliation of individual shoots, if need be.

After leaf drop cut back to visible buds as any farther risks loosing the shoot/branch. Come spring one can again cut back to visible buds, wait, and cut back again until you reach your objective (or there are no more buds).


Eventually, though, you're going to reach a point where you must cut back and/or defoliate (partial or total) to maintain your creation. You will either closely admire your creation watching for buds to appear and rubbing off the ones you don't want OR you will have acquired a sense of how long it takes for it to happen and will come back after the passage of that time to rub buds off from where you don't want them (I think it will be at least a couple of weeks, even in your climate @SU2).

 

[Forsoothe!]

We can't forget that bonsai is a process of matching canopy and root capacity. If you have too much root capacity, you will have excess buds, etc. Rubbing out buds is useful, but not a substitute for balance.

 

[Bonsai Nut]

With aggressive maples, watch the water and fertilizer, rub off the buds that you don't want, cut off the buds in bad locations, and pinch buds as they extend. Then defoliate as soon as the spring growth has hardened.

Second push of growth will be much more manageable.

Also... reading @Forsoothe! comment above, it is really important to develop ramification. When you have a tree pushing growth to 200 buds, it will be less aggressive than pushing growth to 50.

 

[SU2]

That's a pretty good description of why some trees are more adaptable to bonsai than others, and especially why big trees don't make it.

"Don't make it"? Would love any elaboration you could give on this, especially since I have a couple dozen dai/omono sized yamma's in my yard For instance it seems that deadwood-features on non-coniferous species (ie broadleafs IE anything whose xylem has vessels) are guaranteed to fail in short-enough time, I spent a while "getting down" preservation but found that w/o constant, artificial preservation, the wood goes quick -- like in nature. So yeah I've got more than 1 yamma that "is a loser", years into working it, because a large part of its base had deadwood I thought I could preserve. At least BC &Podocarpus are technically coniferous & lack Vessels in xylem so are considered "non-porous wood" which surely accounts for the presence/absence of deadwood on natural conifers/broadleafs)

I'd be really curious not only about the implied death rate ("don't make it" -- unless you just mean aesthetically?), but also about any reasons you see causing this IE why a big tree is inherently different than a smaller tree (aside from the obvious scale difference of course), so far as I ever knew there was not but your post certainly implies(says?) the opposite!

With any species, anytime you've got buds emerging (in spring or after a cutback/defoliation), simply rub off the ones you don't want.. One can avoid knots/knobs doing this instead of waiting until after the buds have released a new shoot.

Also, don't cut until after leaf drop or just as buds swell. 'Letting them run' during the growing season gives the maximum thickening for the year. You can tune the relative strengths with partial or full defoliation of individual shoots, if need be.

After leaf drop cut back to visible buds as any farther risks loosing the shoot/branch. Come spring one can again cut back to visible buds, wait, and cut back again until you reach your objective (or there are no more buds).


Eventually, though, you're going to reach a point where you must cut back and/or defoliate (partial or total) to maintain your creation. You will either closely admire your creation watching for buds to appear and rubbing off the ones you don't want OR you will have acquired a sense of how long it takes for it to happen and will come back after the passage of that time to rub buds off from where you don't want them (I think it will be at least a couple of weeks, even in your climate @SU2).

Just...wow...thanks that is so helpful, honestly I've been on auto-pilot Re maintaining my garden the past ~1yr and the worst part is that this year I have so many trees "transitioning from Development to Refinement", hell I'm online right now Cntrl+H'ing for "maple" before I go out back and prune my 2 yamma's, both have 'run' all season and 'settled into' their last flush of growth, if untouched they'll push another flush of growth (buds are actually already extending) I have a serious space-restriction (lost 2/3rds of my backyard area!) so cannot let things run but thankfully I've got their "skeletons" about where I want and they're about ready for 'hedge/silhouette pruning' instead of the dramatic "grow big / cut hard" repeat routine to make the skeletons/structures!

I always 'balance'/tune as you say the relative branches / leaders, or at least have been this past year or so as my trees finally take their forms, so for both of these Maples the idea isn't more girthening it's to start moving to hedge/silhouette prunings.... That said, and with both of them "being done with their last growth-flush", now seems the best time for a prune if doing another this growing season (and letting them run the rest of the season is neither an option nor even desirable, would get reverse taper or if I restricted the tops enough to prevent that I'd just exacerbate the backbudding )
Love your nonchalance about rubbing-off buds, I think the fear of losing branches has always had me a bit more hesitant than I should be, am going to replant both Maples on one of my main benches (after their ~1-2wk recovery) so I can keep-up with their backbudding, removing most & directing what I want to keep (everyone says 'hands-off those young shoots', I see them as the easiest time to intervene & set the branch collars precisely how you want!!)

 

[SU2]

We can't forget that bonsai is a process of matching canopy and root capacity. If you have too much root capacity, you will have excess buds, etc. Rubbing out buds is useful, but not a substitute for balance.

Balance is certainly necessary (though trees' usual "tolerance range" here is quite enormous if one were to quantify it, I would bet!)

Where is this coming from though, the idea of mis-matching size of canopy // roots? Do you think I'm mismatching? (If so, which way? I use larger containers than anybody I see on here....and my average tree is larger as well)

 

[SU2]

With aggressive maples, watch the water and fertilizer, rub off the buds that you don't want, cut off the buds in bad locations, and pinch buds as they extend. Then defoliate as soon as the spring growth has hardened.

Second push of growth will be much more manageable.

Also... reading @Forsoothe! comment above, it is really important to develop ramification. When you have a tree pushing growth to 200 buds, it will be less aggressive than pushing growth to 50.

I reallllly wish I understood your last sentence....

Thanks for a great reply, I have 2 specimen and spring & early/mid summer 2nd flushing is now finished & hardened (they're ready to do another vegetative flush now, meant to handle them like a week ago)

What are your thoughts on defoliation + pruning? I simply cannot leave some of the 4' branches I have, not only are these branches' collars already as fat as I want them but I need to make space desperately (ie cut things even if it's not ideal) so the pruning of most/all long limbs is gonna happen (thinking of leaving 1 untouched, the top/primary/leader branch, leaving that intact on my "more likely to bud" maple, I suspect that leaving an intact top apical tip will help with the backbudding)

Feel stupid saying this but since I consider fertilizer "their food", I've been giving them high nitro even though I really don't want them on high nitro anymore....thanks again for replying am very glad I thought to come online for replies before going to do the deed!!

 

[Bonsai Nut]

I reallllly wish I understood your last sentence....

Think of the seasonal growth of deciduous trees. In the fall, they stock up carbs and go dormant. In the spring they push those stored carbs out to the available buds. If you have pruned hard and cut the buds by 90%, the remaining buds will be turbo-charged. If you pinch that growth early, the tree will go to "plan 2" and push new buds from the branches/trunk as well as secondary buds from the pinched extensions. You might even find yourself (depending on the species and strength of tree) pinching two or three times before you defoliate. The point is - the more buds you have, the weaker each bud will be (generally speaking) and the less it will extend and the smaller the leaves will be. Prune back a strong tree to one bud and what do you get? A monster branch with long internodes, big leaves, and bad for bonsai

 

[0soyoung]

Think of the seasonal growth of deciduous trees. In the fall, they stock up carbs and go dormant. In the spring they push those stored carbs out to the available buds. If you have pruned hard and cut the buds by 90%, the remaining buds will be turbo-charged. If you pinch that growth early, the tree will go to "plan 2" and push new buds from the branches/trunk as well as secondary buds from the pinched extensions. You might even find yourself (depending on the species and strength of tree) pinching two or three times before you defoliate. The point is - the more buds you have, the weaker each bud will be (generally speaking) and the less it will extend and the smaller the leaves will be. Prune back a strong tree to one bud and what do you get? A monster branch with long internodes, big leaves, and bad for bonsai

In addition to disputing some of what you say (inferences, not observations), I hope to open a discussion on a bit more scientific basis to understand what is going on. I think understanding the whole picture would be a quite powerful insight for practicing bonsai and I wish I did understand it already --> hence my rationale to be a pedantic asshole again.

For decades now, scientists have said that carbs are stored locally. That is, the carbs used by a bud are in the bud or in the vacuoles of living cells nearby. So when one prunes off part of a branch it has no effect on the carbs available to any remaining bud.

Internode length has nothing to do with carbohydrates and everything to do with auxin produced by the apical meristem (branch tip). There is a practice of picking out the center shoot of a. palatium as the leaves begin to emerge in spring. This eliminates the major auxin producer and growth extension stops ('dead in it tracks').

The scientists have told us that when new cells are created from the apical (tip) meristem (bud), they are wrapped with cellulose fibers (the cell wall which all plants have, but animal cells do not) that are helically wound around them. This wrapping assures that when young cells' vacuoles are loaded with water, the cells cannot enlarge radially; they can stretch the coil to elongate the cell. There are, little protein hooks that tie one loop of cellulose to the next. These are hooked by little proteins as the auxin level diminishes away from the apical meristem and locks the cellulose loops together so the and the cell length becomes fixed.
Auxin is produced by the apical meristem and is a nitrogenous compound. Hence more nitrogen = more possible auxin production.

Interestingly, auxin production within a leaf is plays a role in determining the leaf size (or so I have read in scholarly papers). That is, more auxin production in the leaf --> bigger leaves. It seem reasonable to assume that bigger leaves implies there was more auxin even though it might not be (I've noted that leaves closer to the roots tend to be smaller, for example).


Since nitrogen is adsorbed though the roots, pruning removes buds/shoots that may have been nitrogen consumers. The roots, on the other hand, presumably are undisturbed and, therefore, would load the same amount of nitrogen and etc. leading to a situation where more nitrogen is available per bud (as a means of accounting) --> more auxin production --> longer internodes and bigger leaves.


Returning to the renowned Japanese maple maintenance technique of pinching out the center shoot (the apical meristem) of released buds, this stops growth (extension) 'dead in its tracks' because the auxin producer that drives extension has been eliminated. Even though this gets us into another entire level of complications, it is my claim that one could do this to the one bud left after radically pruning the tree in late winter and not get a monster branch with long internodes and big leaves.


In my thinking, the time to pinch out the central leader of newly released buds is after having heavily pruned the tree. This would have the immediate benefit of shortening internodes. On a longer term basis, this also reduces the auxin levels going to the roots, reducing their growth (think, why to not pinch junipers) which pushes the tree toward root-shoot balance. So, one should repeat this exercise with the second and maybe even third flushing until the internode lengths are restored to 'normal'.

 

[Forsoothe!]

"...In my thinking, the time to pinch out the central leader of newly released buds is after having heavily pruned the tree. This would have the immediate benefit of shortening internodes. On a longer term basis, this also reduces the auxin levels going to the roots, reducing their growth (think, why to not pinch junipers) which pushes the tree toward root-shoot balance. So, one should repeat this exercise with the second and maybe even third flushing until the internode lengths are restored to 'normal'."

But there is always a response by the tree to pinching which is to activate more secondary and tertiary buds until such time as growth stops for the autumn. Shorter internodes are the effect of subdividing the resources available to expand buds by having more buds expanding at the same time than would "normally" be.

"...So, one should repeat this exercise with the second and maybe even third flushing until the internode lengths are restored to 'normal'."

Not so. Again, normal internode length returns when pinching stops or is not pursued in the new growing season after the period of no growth (winter/dry season). No??

 

[sdavis]

Any photos?