Maples - repotting and hard pruning

[Antrox]

Hi,
because of the warm weather,
my maples start to bud too early.
I wanted to repot them before the buds opened, and since it was too late, I used some "emergency" pots as figures below.
I used a seed growing tray and a flower pot, just to try to develop shallow roots.
In theory, one should be a maple katsura and the other I am not sure. I also attached a confused photo where you can see the leaves.
My question is related to trunk chopping. I would like to reduce the trees of 1/3, do you think it is possible or best to wait next winter?

Thanks

 

[leatherback]

I prefer big cuts to be made in late spring. You could prune this in a few months. But do it for the right reasons. If you want thickness to be added, keeping all is better.
I feel you may not have enough substrate to full cover the roots there.

 

[Antrox]

Hi,
thanks. Isn't there a problem with bleeding in late spring?

The depth of the tray is about 60mm
The roots are tightened by a wire, do you mean that it could be unstable?
In theory, I should have left growing in a big pot for a couple of years more, but I just made an attempt and see how it goes.
I have never done any styling yet, just working on growing saplings from nursery stocks or from cuttings/seeds.
No idea what to do

 

[Shibui]

Early spring, before and as the leaves are opening appears to be the time maples are susceptible to bleeding though we have plenty of very experienced growers who believe that bleeding is of no consequence. Late spring is a great time for pruning maples.
Any bleeding is stopped immediately with root pruning so is not an issue when trees are repotted and pruned.

IMHO the first maple has not opened leaves enough to preclude root pruning. I've done many with leaves at or even slightly more advanced than that with no problem.
The second tree is just reaching the stage where I would hesitate with severe root pruning but light root reduction should still be possible.

The depth of the tray is about 60mm
The roots are tightened by a wire, do you mean that it could be unstable?

Depth of the pots is not the issue. The reason for covering surface roots is to keep the smaller ones alive and to help them thicken up better. Adding some more soil around the trunk would help maintain those exposed roots until they grow more. If you are happy with the roots as they are there's no problem with leaving as is.
Another approach to improving nebari (visible roots close to the trunk) is to remove smaller higher roots to allow the thicker, better placed roots below to become the surface layer of roots. Good nebari is aesthetic only. Trees can and do flourish with exposed roots and lop sided roots so no real need for urgent attention. Just something to consider for future if you aspire to better bonsai.

 

[Antrox]

Thanks, Shibui, I get it now.
I just exposed them so I could cover them again. I had only a little experience with my portulacaria afra trees where the exposed trees keep growing even though they are exposed.
So, I thought it was the same for the maples.

Regarding pruning, I was thinking of removing one thicker branch and trying to reduce its height as shown in the figure below:



I was not planning to use wire, but I think it would be better earlier than later? thanks

 

[Shibui]

Regarding pruning, I was thinking of removing one thicker branch and trying to reduce its height as shown in the figure below:

Consider removing the thicker of the 2 trunks up top. Retaining a thinner branch helps develop very important taper in a bonsai trunk.

The top cut leaves 2 branches which will probably result in an awkward angle and swelling as they both develop. I get much better results by removing one of the branches as well as the main trunk. Don't worry that you'll lack branches. JM almost always sprout new shoots at the point after such pruning and one of those shoots usually makes a much better branch.
The 3 cuts you've marked will not actually reduce height. The side branches you have left are all as long as the bits you plan to remove so consider chopping almost all branches back in a similar fashion to make the entire tree more compact.
I note you are planning to leave 2 opposing branches at the lowest fork. They may give you a fuller canopy but will eventually cause the trunk to thicken and develop inverse taper at that point. I would consider removing one of those in the near future.
Personally I would cut much harder and then let it grow out again if necessary. Cut and grow helps develop that taper in both trunks and branches.
I know super hard chops don't suit everyone but it appears to be the best way to develop more powerful trunks and branches with more aesthetic bends and curves.

Wiring early is recommended as branches quickly get hard and brittle but you only need to wire when branches need repositioning. I prefer to do most JM development by cut and grow because it is too easy to get wire marks when trees are growing fast in larger grow containers. If you do need to move any branches do it now but definitely keep a close eye on the bark and remove wires at the first indication they are marking the bark.

 

[Antrox]

Thanks for the detailed response.
When you say "cut harder" , do you mean just below the lowest fork? Or just below the upper fork of the 2 ticker trunks (plus cut back each branch)?
I was reading somewhere that JMs do not reach well to hard pruning. So you are saying this should not be a problem?

 

[The Warm Canuck]

I prefer big cuts to be made in late spring. You could prune this in a few months. But do it for the right reasons. If you want thickness to be added, keeping all is better.
I feel you may not have enough substrate to full cover the roots there.

I would second what leatherback says here.

What's you plan with this tree?

 

[Contact]

About cutting trunk and big branches, remember that around June/July Is another good period in my experience with jap maples

 

[Shibui]

When you say "cut harder" , do you mean just below the lowest fork? Or just below the upper fork of the 2 ticker trunks (plus cut back each branch)?
I was reading somewhere that JMs do not reach well to hard pruning. So you are saying this should not be a problem?

JM can sometimes react poorly to big cut backs but that's talking about much thicker and older trunks than you have here and much larger chops than you can make on this tree. Reductions of more than 80% of total branching or reducing the trunk to a stump with no visible buds would be considered hard pruning for this context. Younger trees like this one will usually have no problems.

You have only marked 3 cuts on the photo. I would routinely make those cuts plus cut almost every existing twig and branch back to 1 or 2 nodes. You may be able to see that only reducing the main trunk still leaves a number of side shoots that are sill just as long as the part that is to be removed. A conservative trim of this tree would probably look something like this:

Note that I've elected to remove the thicker trunk up top and retain the thinner trunk and reduce it quite substantially. This should give better taper to your developing trunk and, if the side shown is to be the preferred viewing angle (front) gives a much better trunk line as far as I can make out from the photo. Cutting back all the remaining branches will promote many more shoots to give a more compact and dense canopy and branches.

The next virt shows even deeper chops (red lines) that would reduce the tree right back to a couple of short branches but set up for future improvements as it grows back out. That's how I develop most JM trunks for bonsai. It may take a little longer but gives a much better result in the longer term.

I am confident that this JM can cope well with either of these reductions at this stage.

Please take these virts as advice only. I cannot see the tree in 3D so unsure if the branches selected actually go in useful directions. You should ensure that the branches shown actually grow in good directions before implementing any suggestions made online from photos. You'll get much better advice if you can show the actual tree to someone with a little experience as they will be able to turn the tree and see it from different angles. Joining a local bonsai club is a great way to learn skills and get much better advice in person.

 

[Antrox]

I would second what leatherback says here.

What's you plan with this tree?

HI,
I have no plans, my dream is to.try to get a "chiu" size bonsai, of about 45 -50cm .
Style: informal upright.

 

[Antrox]

About cutting trunk and big branches, remember that around June/July Is another good period in my experience with jap maples

So when they are in full leaves? I thought to need to the dormant period, but I see from everyone replies it seems.better to wait the hot season. Thanks

 

[Antrox]

JM can sometimes react poorly to big cut backs but that's talking about much thicker and older trunks than you have here and much larger chops than you can make on this tree. Reductions of more than 80% of total branching or reducing the trunk to a stump with no visible buds would be considered hard pruning for this context. Younger trees like this one will usually have no problems.

You have only marked 3 cuts on the photo. I would routinely make those cuts plus cut almost every existing twig and branch back to 1 or 2 nodes. You may be able to see that only reducing the main trunk still leaves a number of side shoots that are sill just as long as the part that is to be removed. A conservative trim of this tree would probably look something like this:
View attachment 531312
Note that I've elected to remove the thicker trunk up top and retain the thinner trunk and reduce it quite substantially. This should give better taper to your developing trunk and, if the side shown is to be the preferred viewing angle (front) gives a much better trunk line as far as I can make out from the photo. Cutting back all the remaining branches will promote many more shoots to give a more compact and dense canopy and branches.

The next virt shows even deeper chops (red lines) that would reduce the tree right back to a couple of short branches but set up for future improvements as it grows back out. That's how I develop most JM trunks for bonsai. It may take a little longer but gives a much better result in the longer term.
View attachment 531313
I am confident that this JM can cope well with either of these reductions at this stage.

Please take these virts as advice only. I cannot see the tree in 3D so unsure if the branches selected actually go in useful directions. You should ensure that the branches shown actually grow in good directions before implementing any suggestions made online from photos. You'll get much better advice if you can show the actual tree to someone with a little experience as they will be able to turn the tree and see it from different angles. Joining a local bonsai club is a great way to learn skills and get much better advice in person.

Thank you very much for your detailed reply. I ll save this post for later and update you here when I ll perform the cuts. The majority of the trees I have has started from nursery saplings or seeds. They are too young for real styling ,but I am happy to.try to.delevop them as better I could. Hopefully in 10-15 years, they will be ready for becoming nice bonsais. Thanks

 

[Antrox]

@Shibui
I made a few cuts as you suggested above (hopefully I followed the blu lines you drew), figures below
Should I reduce the lateral branches? There is only one bifurcation for each branch which is quite far from the truck, should I cut before it (there are leaves all along the branch).
Do you I can try to propagate the cutting using a rooting hormone?
Many thanks

before	after