Bottle brush

[Joshua]

Hi,

After killing two bottle brushes last year (the ones on this post), and after spotting this in a nursery, I decided to try again.

bottlebrush-2021-02-side2.jpg

bottlebrush-2021-03-roots2.jpg

bottlebrush-2021-02-base.jpg

What would be the best time of year to give it a heavy prune, bare-root, and start reducing size? Would end of summer or even during summer be okay, after it flowers? (Now it's just about the start of spring over here).

I was planning to leave it alone for now apart from a minimum of pruning where it seems most obvious. The idea is let it go to flower this year before trying to reduce its size. Just don't like the look of those roots. Perhaps a little too close to being root bound?

bottlebrush-2021-02-trunk.jpg

Tried to frame this picture to show roughly the final size I might take it down to. Not sure if I'll keep the double trunk, but that'll be a decision for much later on I guess.


Cheers,
Josh

[Watto]

From my experience around April would be the ideal time for repotting in your area. I wouldn't bare root it but gradually introduce a bonsai mix to it over a couple of re pots, that is over a few years.

[Phil Rabl]

I am close to finishing a summary of AusBonsai post on Callistemon. I hope to post it in a week or so. The information below comes from this summary.

There is a strong consensus in AusBonsai posts that it is best to re-pot Callistemon in the warmer months. Almost every experienced grower recommends re-potting from late spring to late summer. Some disagree with late summer and early autumn re-potting, but others report good results with re-potting at these times. One post, from a grower in Sydney, says you can re-pot Callistemon throughout the year because they never stop growing in the Sydney climate. Other posts indicate that Callistemon are more likely to survive a winter re-pot than other Australian natives. But, the overwhelming advice is to re-pot in spring and summer when the tree is actively growing. There is advice to avoid re-potting in a heatwave.

I don't recall anyone saying they bare root Callistemon.

Hope this helps.

[Joshua]

Thanks Watto and Phil,

A day or two ago I found this [Species guide] post, and this one, at the top of the Callistemon page in the "Australian Native Species" section.

The first mentions that potting and digging (so I assume also root work) can be done at the start of spring just as the buds are swelling.
Both also mention they require heavy pruning after flowering.

I was thinking of starting to pot it down next year (and hopefully I'll have a source of bonsai mix by then).
So for now I'll just trim the roots back a little and repot into potting soil in the same pot, just to prevent it getting rootbound before next year.
Then toward the end of summer (after flowering if it decides to flower) cut the top back fairly hard.

Thanks for the work on the summary that'll be good to see I'll keep an eye out for it.

[greg27]

I'm not sure of the species but I've bare-rooted a callistemon (viewtopic.php?t=28997) and it didn't care.

Aussie Bonsai Bloke has a few videos on cutting back a callistemon after flowering. Plus his videos are always good fun.

[dansai]

Ive gone pretty hard on Callistemon roots, and they only grew back stronger. I usually go pretty hard on all nursery stock trees as I find the roots can be pretty messy and best to get it done as soon as possible. No use spending a few years working on a tree only to find roots are totally crap and you end up losing it when you try and reduce them. I used to lose a few trees to this but not too many any more, unless all the roots come from the one root that formed on the original cutting and twists and turns before branching. I also try not to over pot them. Any new root growth, which is what feeds and waters the tree not the old roots, will mean good strong top growth. So regular root pruning will usually produce better growth and better roots than planting straight into large containers in my experience.

[Joshua]

Hey all,

Finally did the repot today.

I was hesitant about it because it's going to flower soon and madame let me have it on the condition that we don't torture it too much at least this year - she wants lots of flowers. But the pot seemed to me too small for its size, and I didn't want to just slip pot it up: as you guys mentioned, best to start getting them sorted as soon as possible.

So the objective today was to dig down to see where the base of the trunk is, or at least see what kind of nebari there might be, and to give it a light root prune with not too much damage.

I was planning to do it earlier but we kept getting unusual cold snaps this spring (I hear a lot of fruit growers are having trouble this year around here), and preferred to wait until it warmed up a bit. Everyone seems to mention it's safest when it's warmer and it's actively growing. (Although in Pup's thread on bottle brush pruning (viewtopic.php?f=55&t=2641) he mentions that repotting should be done at bud break, so perhaps I was a little too late?)

I might have gone a bit too hard on it. It started having a big sulk not long after and when it went back in the sun. A bit nervous about how well it will bounce back, but we'll see.

full_size_before.jpeg

^ Here it is before starting

full_of_flower_buds.jpeg

^ Full of flower buds, feels like they're due to open any day now.

current_pot.jpeg

^ Just to show the previous and new pot and the size.

future_pot.jpeg

^ Started by preparing the next pot. Wider than the previous one. I put an small inverted pot in the bottom and some clay balls around that to reduce the depth a little. I left a gap in the clay balls though so some of the soil could go right down to the holes at the bottom, thinking that it will be possible to let it soak if ever necessary and the soil will be able to wick up the water.
For now also just using potting soil and not a bonsai substrate.

roots_at_base1.jpeg

^ After scratching away at the soil mostly from the top, managed to dig down to some of the first thick roots. I don't get the impression the trunk goes much further down below these but hard to say.

roots_at_base2.jpeg

^ Another of the future potential nebari.

rootball1.jpeg

^ Root ball before potting it up. I had to remove a bit from the bottom so that in the new pot it wouldn't sit too high on top of that inverted pot.

rootball2.jpeg

^ Again root ball

almost_done.jpeg

^ Sitting in the new pot, topping up with soil.

sulk1.jpeg

^ And just after...

sulk2.jpeg

^ It was sulking pretty bad. I left it soaking in the tray under the pot though and gave it a good misting. Also moved it out of the direct sun and against the wall where it should get a bit less wind.

A few hours later now and it's perked up quite a bit already.

[melbrackstone]

I'm sure it'll be fine as long as you can keep it warm and out of the wind for the next few weeks. It may sacrifice some of those soft tips itself, but the tree itself should be ok.

[Joshua]

After the repot/root prune we had a good couple of weeks of overcast humid weather with basically no wind so perfect for the recovery.

Just last weekend I gave it a hard prune on top since it was just about finished flowering. There were just a few left that looked like they would have lasted a few more days perhaps a week so not sure if it was too soon or not.

Before and after the prune:

callistemon before haircut 2021-06-01.jpeg

callistemon after haircut 2021-06-01.jpeg

callistemon after haircut 2 2021-06-01.jpeg

It'll probably be my first tree to put in a small pot and I think I'm starting to over-think it.
Any advice for how to proceed over the next year or two?

[shibui]

For what it is worth I would have trimmed much harder than you appear to have done. Most new shoots will grow from the leaves closer to the ends so those long branches will still be quite bare and straight with just a few new shoots near the tips. One good thing about callistemon is that you can still prune harder in a few years and get good budding.

There will be a range of possible ways to proceed from here. Some will depend on what you expect from your tree.
Many beginners are in a hurry to get a tree in a bonsai pot so they are happy to put a skinny trunk in a pot and call it bonsai. That is OK provided you accept that will slow any future thickening and branch development. Having an exotic like callistemon and getting flowers may be worth the trade off in growth for you.

A thicker, more impressive trunk with mature bark will develop quicker if the tree is allowed to grow quicker in a larger container. Minimal pruning should increase thickening and is OK because these bud so well on older wood. I would try to maintain some smaller side branches that can be used to cut back for taper and change of trunk line when the time comes.

The 2 thicker trunks don't do much for me so I would remove the straighter one at some stage but it is currently very useful as a sacrifice branch to help thicken the lower part of the trunk.
Dead wood is common on callistemon in the wild here so I have used excess branches as jins on some callistemon bonsai. Callistemon dead wood is not durable and rots relatively quickly unless treated regularly.

Whatever you decide this should produce an attractive talking point on any French bonsai bench.

[Phil Rabl]

I mentioned in an earlier post in this discussion that I was close to finishing a summary of AusBonsai posts on Callistemon. It is now finished. Here is a link to it: viewtopic.php?f=55&t=29478. (I’m a little surprised by the small number of views – I thought Callistemon was more popular than it appears to be.) Hope you find it useful.

[Joshua]

I mentioned in an earlier post in this discussion that I was close to finishing a summary of AusBonsai posts on Callistemon. It is now finished. Here is a link to it: viewtopic.php?f=55&t=29478. (I’m a little surprised by the small number of views – I thought Callistemon was more popular than it appears to be.) Hope you find it useful.

Cheers Phil. I had actually seen it and I've been reading through it. Really good stuff.
I think my main problem is choosing what direction to take it in, as Shibui mentioned there are a lot of options.

[Joshua]

Thanks for the response Shibui!

For what it is worth I would have trimmed much harder than you appear to have done. ...you can still prune harder in a few years and get good budding.

Would it be too late to go and cut it back further straight away, or is it better to let it recover a while first?

I wasn't sure how much to cut off. I guess I was thinking of cutting it back gradually over a couple years, and leaving a bit more growth on it for now while still working on the roots. Also thinking that leaving some more on it would improve development in the meantime.

Would a better idea be to cut it back much harder to encourage more lower backbudding, then let it grow out big again over a couple of years? (and eventually a number of cycles like this?)

Many beginners are in a hurry to get a tree in a bonsai pot so they are happy to put a skinny trunk in a pot and call it bonsai. That is OK provided you accept that will slow any future thickening and branch development.

The trunk at the base is max 3.5 cm, so (looking at the 'rules') I figured that's thick enough to have a final size of around 30-35cm. The bifurc' is about 10cm up from the base.

I was pretty keen to start working it toward a smaller pot and into bonsai soil, since it would be a first and it would be kind of an experiment for me. I also thought that that would be the next step once the trunk and roots are at where I wanted and that branch development could come later. But happy to leave it in it's current pot for a while longer, which is fairly large but not huge, and start trying to develop some branches. Not necessarily in a rush to get it in a bonsai pot.

I guess my question is to know, assuming I'd be happy with that size and trunk thickness (although a bit bigger would be better), what would be the next phase and how to go about it.

The 2 thicker trunks don't do much for me so I would remove the straighter one at some stage but it is currently very useful as a sacrifice branch to help thicken the lower part of the trunk.

Exactly one of the points I was wondering about. The straighter one is a bit thinner and the more interesting one is fairly thick so not doing much for taper.
Maybe then I should cut back the latter hard to stunt its growth, say to its lowest branch, and leave the straighter one as it is for the time being?


Edit: another option could be a more drastic trunk chop...

[shibui]

I would cut Callistemon any time of year. Even soon after a previous prune will not worry it so if you do want to reduce the trunk or longer branches feel free to do so. Hard to stop a Callistemon by pruning.
Leaving more on now will improve trunk thickening so there is not just one way forward unfortunately.
Both ways will give a bonsai just different paths to the same destination.

Given you are happy with the trunk thickness it is now time to start working towards getting better branching and reducing roots. I'd be happy to do all that in one operation. If it was here I would reduce roots by up to 80% and reduce top to force better shoots all in one go but that may be too traumatic for you. It is also possible to do that in stages if that suits you better - just 2 different paths to the same or similar outcome.

Lack of taper can be remedied by chopping. There is a convenient small branch on the thicker trunk - probably about 20 cm up (twice height of main fork) that looks like it is growing more upright than a normal branch. That would be a good spot to reduce the main trunk then shorten that long branch. Given that it is healthy and growing well You could chop there and leave the other trunk alone but sometimes a higher trunk will suppress new growth on shorter branches so I would be inclined to chop both at the same time for maximum effect. I'd cut the smaller trunk just above some small shoots above the main fork at the same time as chopping the main trunk. Again, that's just my preference and there will be other possible ways to get to a similar result.
I usually use a series of chop and grow cycles to grow a good trunk with taper and bends. Gradually work up to the full height and spread building ramification as it grows.

Don't get too worried about the 'right' way to grow this one. It may seem to be a strange and exotic species to you but it is still a Callistemon. They are usually very resilient and will recover from almost anything.

[Joshua]

Awesome thanks.
It's only just had its first ever root prune so I think I'll let them fill out the pot a bit more before pruning again.
I might go for that double trunk chop for now and try to get some cuttings out of the removed material.