[Bougainvillea Pruning] Hoping for advice on how to approach

[Iheartbougs]

[to be clear I'm in the US and it's mid-summer right now, our daily temp is breaking 80deg and the rainy season is starting ie daily showers ]

I've got scores of propagated bougies (all hardwood propagates, ~2" thick minimums, they root so successfully here it's insane ), anyways I'm not even 2yrs into bonsai and only really started to 'get' things last year, am afraid I may still be messing-up in how I'm approaching my 'initial branch-development prunings' ('hard-prunings', technically - at least that's the lingo I'd use on bonsainut or Reddit)...

I've got a bougie that, after things were waking up for me a few months ago in spring, I hard-pruned back to the bottom 2 nodes on all branches; it subsequently grew-out again and is now ready to start flowering (have removed a couple actually, this one isn't so bad about trying to flower - I hate flowering, beautiful but waste of resources on in-development trees!), I'm looking at this and *think* it needs pruning, I guess I'd be approaching it the same IE I'd be clipping-back ('hard-pruning') each branch back to 2 nodes apiece - is that the right move right now? Or should I let these primaries stay as-is, remove the flowers as they form, and wait for more girth before doing another pruning?

Here's a picture of the guy I just took now:



, and here's https://imgur.com/a/PPruUKo a chronological, curated album of this guy - am on the fence about what to do right now, some people would put wires on every branch now wouldn't they? Or is this the type of thing where I should just keep growing, pinch flowers off as they form, and wait til there's more girth before hard-pruning back to 2 nodes to get my next level of ramification? (further, how many 'rough' levels of ramification do people tend to do this way when developing stock? I know at some point you're really just tending your already-made pads on top of your branch structure, but guess I'm unsure whether a typical trunk-chopped specimen (ie all primaries are being re-grown) needs 3-4 rounds of grow&hard-prune before wiring and 'clip&grow' techniques (ie starting first-level refinement), or 10 rounds - any & all thoughts on this are hugely appreciated, have so many specimen where I'm stuck at this point and unsure what to do, whether I should be pruning to push another flush or trying to coax growth out of the branches as they are (ie by removing flowers, keeping in sun & keeping from getting too dry & high nitro / low phos)


(I guess my confusion stems from the fact that I don't know at what point I should be moving from "heavy grow-out & subsequent hard-prune" to just leaving my primaries, keeping them and wiring them out and no longer doing *any* hard-prunes, only clip&grow-type manipulations from that point)

[edit- should add that the slight chlorosis - hard to see in that last pic but it's there - is likely due to a problem I had, didn't realize how much water it was retaining and suspect that's the cause - it gets plenty of fe/mg+ at <5pH water so no way it's iron/magnesium deficiencies I'd imagine, have remedied the water issue (was insufficient drainage]

[Starfox]

If you are stuck and have quite a lot of them all in a similar state then I would say it's a good opportunity to do a number of different things and take notes. See how they respond to cutting back to two nodes or just tip prune and see where they back bud. Set aside some that you want to thicken up and do nothing for a year or two type of thing. If you want to thicken a branch I would leave it alone to grow too, try wiring but beware you may lose the branch as they are very brittle and you should do it on as early growth as you can get away with.

Let the trees speak to you in the sense of how they want to be developed, some may be great us an upright or a cascade. Look for the shape you want it to be and start along getting it there. And if you can't see the end vision yet then let them grow but be selective. Keep buds and shoots that alternate, cut out doubles, y sections and bar branches and let the rest grow.
If it was me, maybe I would just prune 50 percent of each shoot and see what back buds. Put wire on if you can for movement on shoots you want to keep and then reevaluate in late July. Personally too I leave the flowers alone, they grow regardless of them and it's doing it's natural thing but if you have lots of them to play with try leaving some flowers on certain plants and clip the others off and see the comparison.

[Iheartbougs]

If you are stuck and have quite a lot of them all in a similar state then I would say it's a good opportunity to do a number of different things and take notes. See how they respond to cutting back to two nodes or just tip prune and see where they back bud. Set aside some that you want to thicken up and do nothing for a year or two type of thing. If you want to thicken a branch I would leave it alone to grow too, try wiring but beware you may lose the branch as they are very brittle and you should do it on as early growth as you can get away with.

Let the trees speak to you in the sense of how they want to be developed, some may be great us an upright or a cascade. Look for the shape you want it to be and start along getting it there. And if you can't see the end vision yet then let them grow but be selective. Keep buds and shoots that alternate, cut out doubles, y sections and bar branches and let the rest grow.
If it was me, maybe I would just prune 50 percent of each shoot and see what back buds. Put wire on if you can for movement on shoots you want to keep and then reevaluate in late July. Personally too I leave the flowers alone, they grow regardless of them and it's doing it's natural thing but if you have lots of them to play with try leaving some flowers on certain plants and clip the others off and see the comparison.

I failed the comparison-testing, didn't setup enough control-branches and lost the growing-tips on 3 of them (mold and caterpillar issues, finally "under control" at the current moment, we're in our rainiest part of the year though so it's a constant battle!), but I just can't fathom that leaving the flowers on = faster **long-term** growth than taking them off! I emphasized *long-term* for a reason, I'd been thinking about this and no matter how you slice it, flower-growth is a net-loss because the leaf-like bracts & flowers don't photosynthesize, so my thinking is that if you DO let it flower, you probably get MORE growth/girth during that time-period while it's pushing the flowers(and some vegetative) growth, however no matter what the flowers' development requires energy the tree would have otherwise used or stored towards other purposes than reproduction, depriving it of putting out non-photosynthetic growth has just got to equal better vegetative growth over seasons-long time periods (I suspect that, if I only tested a 2mo period, that the ones that I let flower would actually get thicker branches - but they'd be weaker specimen at the end of that period in comparison to the trees that didn't have to fully develop such abundant masses of bracts/flowers!

I've started to think that clipping the flowers may actually be speeding growth *because* it wants to flower- when it's deprived, it tries to grow longer so it can have new nodes w/ flowers - I could just be delaying an inevitable but fixed-amount of flowering, will have to wait the next pruning to see! I'm fine with them flowering in the winter, though for now I'm hoping to do 1 more moderately-hard-pruning to most of them as they are all giant bushes right now and I'm barely past the halfway point of my growing-season (have already done 1 hard-prune to everything, some crapes have gotten 2 hard-prunes already!)