Phasing work on my Shimpaku Juniper

[pandacular]

I have a shinpaku juniper (Juniperus chinensis) that I purchased as a pre-bonsai (though I'm thinking penjing!) from Robert Cho at Asia Pacific Gardening. This tree has a really interesting trained trunk line, and tons of foliage, some of which has been trained as well. Here are some pictures of the tree the day I got it. The first image shows the preliminary front, the second is 90 degrees counterclockwise.



Currently, the only things I've done to this tree are some cleanup (minor branch selection, taking out tops/bottoms/crotches, and cutting back growing tips) as well as wiring a few branches for photosynthetic efficiency. Here are some pictures of tree after cleanup (taken on a different camera, hence the change in color/luminance):

Over the course of the next year or so, I would like to do the following work on the tree:
1) Repot it into an Anderson flat, or similar container
2) Prune back the longer branches, and boy are the long. Particularly, the branches on the left and back are quite long and need to be managed
3) Wire it up to make all those straight branches match the highly contorted trunk.

My question is regarding timing of these various tasks. The only one I'm certain on is that I must repot in the spring. This is the highest priority of the three, as I don't believe the tree has been repotted in quite some time, and the surface layer is bursting with roots. The substrate, which I believe is pure pumice, is not an issue, but I would like to work the roots and begin preparing it for a bonsai container.

On pruning, I've several different possible times provided, from all year round, to any one of the specific seasons (with the exception of early spring). I understand that this is likely one of the many "it depends" factors, which is why I'm curious for advice on this specific tree, with the scope of work I have planned. I can see arguments both for doing this ASAP, to get some more growth in this season, as well as waiting until dormancy to do it.

Finally, I would also like to wire the tree. I generally see this recommended as a winter or fall activity on junipers, but I would not like to risk the tree being set back during a repot or prune to get some wire on there. It also makes sense to me to do this after pruning, both to make the design clearer and to make it physically easier to work the tree.

I've attached several more pictures of the tree from today, including some close-ups. My ultimate goal is to achieve as much of this work as possible while balancing the health of the tree and avoiding waiting too long to get it all done. I really love this tree and think it has great potential. Thanks in advance for your help!

 

[pandacular]

As an aside, I never know what to call Juniperus chinesis. Shimpaku, shinpaku, Sargeant, scientific name, common name, Yuán bǎi...so many more names than most speices!

 

[pandacular]

I spoke with my teacher about this, and she recommended doing the prune and wire at the same time. My local bonsai club next's meeting, in late September, is a bring your tree workshop, so this work might be a good candidate for that.

 

[WNC Bonsai]

This is a pretty good video on shim(n)paku styling for a beginner. It can be hard to figure out some of the translation in the subtitles but after a while you get used to it. The stuff they do is really eye opening sometimes. Tojuen is one of the famous bonsai gardens/schools in Omiya Japan. I think Mr Kimura trained there.

 

[pandacular]

Thanks for this resource! I'll take a look at it when I'm free. While I have you hear, would you care to share your thoughts on my plan?

 

[pandacular]

It blows my mind what prices you can get excellent trees for in Japan. ¥5000 for that tree! Are you kidding?? I should've brought an extra suitcase for trees when I went.

Of course, when I visited Japan this spring, I was not quite as awake to the world of bonsai as I am today; my next visit will be much more bonsai focused.

 

[WNC Bonsai]

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It blows my mind what prices you can get excellent trees for in Japan. ¥5000 for that tree! Are you kidding?? I should've brought an extra suitcase for trees when I went.

Of course, when I visited Japan this spring, I was not quite as awake to the world of bonsai as I am today; my next visit will be much more bonsai focused.

Yes they are amazingly cheap but then they have a large number if rowers developing trees for bonsai. In addition with the population shrinking every year they have fewer a d fewer customers to buy those trees so demand goes down and proces do too. That is a reason they give fir creating the binsaiQ channel to help promote the hobby in Japan and keep it alive. As for bringing them back the process to bring trees to this country is very difficult requiring bare rooting the trees and shipping them to a nursery with an importation license and quarantine facility. Assuming the tree survives the bare rooting they also have to be held there for 6 months or more, so only really worthwhile trees get imported.

 

[WNC Bonsai]

Thanks for this resource! I'll take a look at it when I'm free. While I have you hear, would you care to share your thoughts on my plan?

I assume you mean pruning and wiring in September? I would think that would be OK. I usually work on my junipers in spring.

 

[pandacular]

Specifically, prune + wire in September with a repot in the following spring. The key thing I'm looking for is not jeopardizing the repot by overworking it.

I see a lot discussion about over-working trees and setting them back. I'm trying to get a clear picture, with a concrete example, of what that might look like.

 

[Srt8madness]

It blows my mind what prices you can get excellent trees for in Japan. ¥5000 for that tree! Are you kidding?? I should've brought an extra suitcase for trees when I went.

Of course, when I visited Japan this spring, I was not quite as awake to the world of bonsai as I am today; my next visit will be much more bonsai focused.

Unfortunately you can't bring trees back to the U.S. from Japan (short of permits, bare rooting, and 2 year quarantine period). Would be great to visit some nurseries still!

 

[pandacular]

Yeah, judging by all the signs in customs I know it wouldn't be easy. I totally get it, but it's a shame. I wonder if professional importers are subject to same restrictions? I almost never see imported pines for sale, perhaps due to the bare root requirement.

 

[Shibui]

Love these twisted trunk junipers. So much more character than if allowed to grow naturally which generally gives lots of straight, untapered sections. I've also been growing similar for the past 10-15 years.

Prune and wire any time from mid summer through to winter. Earlier pruning will allow for regrowth before the spring repot. Junipers seem to cope better with root reduction if they have intact growing leaders. I seem to have better recovery of field grown shimpaku into pots if I leave several long branches than when I pruned all over.
I'd be comfortable with a fall prune and wire followed by a spring root reduction and repot.

As an aside, I never know what to call Juniperus chinesis. Shimpaku, shinpaku, Sargeant, scientific name, common name, Yuán bǎi...so many more names than most speices!

Chinese juniper grows isolated on mountain tops. Over time each mountain population has evolved into s slightly different form - shape, size, colour, etc. Growers refer to different types by the mountain or region they come from to differentiate so there's a few names.
It is also spread over several countries and each language has developed a common name for the species so there's another 5 or 6 names.
We also have the English common names that were given to species when they were first collected and introduced to Europe. Some of the very variable junipers like J. chinensis look so different they were also thought to be different species so the different varieties were given names, some of which have stuck.

 

[Paradox]

Yeah, judging by all the signs in customs I know it wouldn't be easy. I totally get it, but it's a shame. I wonder if professional importers are subject to same restrictions? I almost never see imported pines for sale, perhaps due to the bare root requirement.

There are a few big operations that do it. I forget which but either Wigerts or Brussel's imported a bunch a few years ago. They quarantined them in a separate greenhouse for the required two years. Many died and what survived were very pricey (justifiably so) to cover their costs. Not sure if they are still doing it or gave up due to cost and delayed/lack of profitability.

 

[Paradox]

As to the original question.
Repot in spring as buds begin to swell

Wire in fall.
You can prune some in the fall but keep in mind that juniper store their energy for winter in their foliage not the roots so you need to be careful about how much you remove in fall.

I would do major pruning in spring one year after the repot as it starts actively growing.

 

[MaciekA]

@pandacular watch this:

Shimpaku is just an informal grouping of cultivars under j. chinensis.

 

[pandacular]

keep in mind that juniper store their energy for winter in their foliage not the roots

I hadn't heard this before. Do you have a place I can read more about this? Upon searching this in Google, the only place I see this mentioned is kn here by you, so I'm curious to find if this is informed by experience or something else.

I am considering doing an earlier prune as soon as... well, whenever I get the chance and then saving wiring for the workshop.

 

[Paradox]

I hadn't heard this before. Do you have a place I can read more about this? Upon searching this in Google, the only place I see this mentioned is kn here by you, so I'm curious to find if this is informed by experience or something else.

I am considering doing an earlier prune as soon as... well, whenever I get the chance and then saving wiring for the workshop.

I don't have a reference but it's been talked about in bonsai here and elsewhere since before I started. I've heard it here from experienced folks, from professionals like Ryan Neil and Bjorn and people doing demos at bonsai shows. It's a very commonly discussed thing when talking about junipers.

I've never chosen to challenge the concept and just hack away at my juniper whenever the mood strikes me. I figure there is a reason it is frequently mentioned in bonsai.

 

[pandacular]

Also, I think the correct term for my pruning plans would be structural pruning, rather than smaller, maintenance pruning. Not sure if that changes the plan significantly.

 

[Paradox]

Structural pruning would indicate to me a much greater removal of foliage compared to maintainence pruning. I would prefer to do that when the plant is actively growing since it will promote healing of scars faster if you are not planning in jinning the branch or branches.

I'm not saying you can't prune at all in fall but you need to be careful how much for the reasons stated.

 

[pandacular]

Time to do a Mirai archive deep dive. I have this piece in my notes for this tree

>prune back larger pieces. according to the Juniper Pruning video, junipers are best pruned in late or mid summer, but can also be pruned before bud break.

I've also seen a few videos on structural pruning on there, but I don't think I've watched them. The prune is the most likely piece of my plan to get cut or pushed back, as it seems much more likely than wiring to jeopardize my repot next spring.