AusBonsai

When is the best time to prune my Trident Maple? I'm assuming it's in the middle of winter, can can someone please verify?

It's my understanding that you should do it in late winter, before bud burst. Hopefully someone more experienced can comment soon for you though

are you talking about root pruning or branch pruning ?

It depends on what you are trying to do with the plant. Brent Walston had a good article on this.

Pruning in winter, or before bud burst, concentrates all stored nutrients into only a few buds, causing rapid, ungainly growth. If done in early winter, branch pruning can also stimulate more buds to shoot on the plant in spring. Root pruning and branch pruning at the same time balances nutrients and demand. I tend to time heavy branch pruning and trunk chopping with heavy root pruning on Tridents. Pruning after spring shooting removes the new growth and most of the stored nutrients leaving the plant weak, so regrowth is smaller with shorter shoots. Walter Pall has an excellent article on his blog at the moment on how maple can be pruned. Don't prune in autumn is just a blanket rule for tridents.

It's a kind of complicated part of training a plant, many seem to just prune to a timetable, but the results are different for different times of the year, and what phase of development the tree is in. Knowing what will happen, when, enables you to develop a better. healthier tree.

So do your self a favor and read those two articles.

Paul

What stage is the tree in - development or refinement? Tridents generally benefit from winter pruning in late winter - go for about a month before you expect new buds, but not too soon after it drops its leaves as energy stores are still moving from branches to roots at this time. For root pruning the generally accepted best time is just as the buds are beginning to swell. Just keep an eye on the tree.

And I say almost anytime is the right time for pruning tridents but it is easier to see what you are doing when there are no leaves on the tree. The only time of year I avoid pruning is bud burst when many maples tend to bleed profusely in pruned but, even then, root pruning will stop the flow almost immediately.

Make sure you differentiate between pruning and pinching. Most of us use 'pruning' to mean larger cuts say 6mm diameter and larger. Pinching is cutting smaller shoots and is done whenever the tree needs it.

Many myths have grown up aroung horticulture and become entrenched. Not long ago we were told that deciduous fruit trees had to be pruned while dormant in winter. Now commercial orchards routinely summer prune with excellent results. I believe similar myths have been propagated around bonsai. I think someone asked a Japanese grower when he pruned his trees and he said 'winter'. This was passed on and soon became 'must be winter' and later 'can only be pruned in winter' when what the original grower meant was 'I prune in winter because it is easier to see what I am doing when there is no leaves'. Some problems in translation and lots of issues with the story being embellished leads to many myths

Good thread peeps and some great discussion and references.
For those not so savvy here is the aforementioned WP thread: http://walter-pall-bonsai.blogspot.com.au/
I found it to be a great read.

Andrew Legg wrote:Tridents generally benefit from winter pruning in late winter

Well, yes, that's kind of true. But there are other options. Say your tree is quite advanced, there's not going to be a lot to prune off, just the odd shoot here and there. So if you wait, the new spring growth won't be as strong as if you had pruned (especially if you had root pruned) wait until it has sprouted 2-3 sets of leaves before pruning, or wait till later in spring, then again, the next flush will be smaller with shorter nodes, as well, it will help develop lateral buds.

I have tridents in different stages of development; young trees I root prune and chop and repot about a month after they lose their leaves. So that would be the start of June, or late May. Middling trees get repoted, heavily root pruned (90% of roots) and branched pruned in late July/August. Established trees just get a tidy up, pruning back stubs were branches have been removed, which wouldn't be more than 10% of growth. I repot these plants with lighter root pruning (30% max) as buds swell and wait until December to totally defoliate, really prune, and wire these guys. I do different things to the same species depending on the degree of advancement.

Andrew Legg wrote: For root pruning the generally accepted best time is just as the buds are beginning to swell.

Yes, it is the best time. But you can do it from a few weeks after leaf drop till when the first set of leaves are out. There is a broad time range in which you can repot. Thankfully.

Check out Peter Teas blog, there is an excellent article about defoliating, pruning and wiring Tridents.

Cheers

Paul

it is the best time. But you can do it from a few weeks after leaf drop till when the first set of leaves are out. There is a broad time range in which you can repot. Thankfully.

I think there may be an even broader time than this. This summer I trialled repotting some (young, small) tridents in full leaf in summer. All 3 survived and grew on strongly. can't tell the difference now. I have not been game to try it with a more advanced tree yet though.
More details on my blog here:http://shibuibonsai.com.au/is-it-too-late-to-repot-my/

Say your tree is quite advanced, there's not going to be a lot to prune off, just the odd shoot here and there

Paul, I am finding there is quite a lot to prune off my more advanced tridents. They have reached the stage where branches and twigs are congested and need regular thinning to make room for more shoots.
Your comments re deferring pruning until later in spring to get smaller internodes and more lateral buds have given me food for thought and some more trials next season, Thanks.

Shibui wrote:

Your comments re deferring pruning until later in spring to get smaller internodes and more lateral buds have given me food for thought and some more trials next season, Thanks.


This concept comes from an article that Brent Walston wrote. I'm not sure if you have read these articles, but here is the link,

http://www.evergreengardenworks.com/pruning2.htm

He says it so much eloquently than I ever could, plus provides much more information then I can using this form of communication, forums are best for the short answer, not long ones.

Regards

Paul

Shibui,

I read your blog article regarding potting timing, and I have decided you're a braver man than I.

Paul

63pmp wrote:

Andrew Legg wrote:Tridents generally benefit from winter pruning in late winter

Well, yes, that's kind of true. But there are other options. Say your tree is quite advanced, there's not going to be a lot to prune off, just the odd shoot here and there. So if you wait, the new spring growth won't be as strong as if you had pruned (especially if you had root pruned) wait until it has sprouted 2-3 sets of leaves before pruning, or wait till later in spring, then again, the next flush will be smaller with shorter nodes, as well, it will help develop lateral buds.

I have also found that holding off fertilising tridents until the first set of growth has hardened produces far tighter internodes and growth in this first flush. The you can load on the fertiliser once again.

Hi Joe

Thanks for chiming in. The more people who contribute, the better this thread gets. And it's an important thread.

Jow wrote:
I have also found that holding off fertilising tridents until the first set of growth has hardened produces far tighter internodes and growth in this first flush. The you can load on the fertiliser once again.

Yes, and I think its true for just about all deciduous trees, but particularly for cold climate ones. It has to do with nutrient storage in autumn. Deciduous plants store all the food they require for spring in their roots and to some extent, their trunks. (They store nutrients in forms that won't interfere in metabolic processes, N is in the nitrate form within the vacuole of the cells, P as semi-soluble complex and energy as starch. Salts such as K calcium, magnesium iron etc are stored about the plants structure. For instance calcium is in the lining of phloem vessels, K in the cytosol and vacuoles.) When spring comes these nutrients are mobilized and pushed up the phloem vascular tissue to the buds. At this point the only thing roots really want to take up is water. (If we feed now then there is an excess of NPK, which causes excessive growth and leads to problems with large leaves, long nodes and blights, and there are other problems that can occur)

This flush of leaves is necessary for the hormonal pathways to develop. Plants rely on the auxin/cytokinin hormones to develop nutrient pathways, a plant doesn't have any real direction until auxin is formed in the shoots and it reaches the roots. In spring, it simply pumps water up the phloem and allows the buds to develop. I would think nutrients would start flowing soon after when auxins reach the roots and initiate new root growth and pathways.

For deciduous trees early spring feeding is not necessary. If you must fertilize, add things like K, Mg, Ca, trace elements, these will improve health but not force growth. Don't add N and P.

Plants also store a little bit of food behind the dormant buds, so that in spring, when growth is initiated, all that the bud requires is water to get going.
When we root prune as buds are swelling, or before, we remove a lot of the nutrients required by buds for continued growth, but buds still shoot because they have their own food source. Leaves and shoots remain small because of an absence of stored root nutrients.

So we get the best ramification if we root prune in late spring, but wait until after the first few leaves have hardened off before branch pruning. Of course it depends on how much root you remove. An advanced tree may only have about 30% or less removed (or nothing at all) while something from a field may have 90% removed. Obviously you would let the replanted field tree recover for several months before pruning it.

Paul

63pmp wrote:Hi Joe

Thanks for chiming in. The more people who contribute, the better this thread gets. And it's an important thread.

Jow wrote:
I have also found that holding off fertilising tridents until the first set of growth has hardened produces far tighter internodes and growth in this first flush. The you can load on the fertiliser once again.

Yes, and I think its true for just about all deciduous trees, but particularly for cold climate ones. It has to do with nutrient storage in autumn. Deciduous plants store all the food they require for spring in their roots and to some extent, their trunks. (They store nutrients in forms that won't interfere in metabolic processes, N is in the nitrate form within the vacuole of the cells, P as semi-soluble complex and energy as starch. Salts such as K calcium, magnesium iron etc are stored about the plants structure. For instance calcium is in the lining of phloem vessels, K in the cytosol and vacuoles.) When spring comes these nutrients are mobilized and pushed up the phloem vascular tissue to the buds. At this point the only thing roots really want to take up is water. (If we feed now then there is an excess of NPK, which causes excessive growth and leads to problems with large leaves, long nodes and blights, and there are other problems that can occur)

This flush of leaves is necessary for the hormonal pathways to develop. Plants rely on the auxin/cytokinin hormones to develop nutrient pathways, a plant doesn't have any real direction until auxin is formed in the shoots and it reaches the roots. In spring, it simply pumps water up the phloem and allows the buds to develop. I would think nutrients would start flowing soon after when auxins reach the roots and initiate new root growth and pathways.

For deciduous trees early spring feeding is not necessary. If you must fertilize, add things like K, Mg, Ca, trace elements, these will improve health but not force growth. Don't add N and P.

Plants also store a little bit of food behind the dormant buds, so that in spring, when growth is initiated, all that the bud requires is water to get going.
When we root prune as buds are swelling, or before, we remove a lot of the nutrients required by buds for continued growth, but buds still shoot because they have their own food source. Leaves and shoots remain small because of an absence of stored root nutrients.

So we get the best ramification if we root prune in late spring, but wait until after the first few leaves have hardened off before branch pruning. Of course it depends on how much root you remove. An advanced tree may only have about 30% or less removed (or nothing at all) while something from a field may have 90% removed. Obviously you would let the replanted field tree recover for several months before pruning it.

Paul

Great post Paul,

Intersting what you say about the blights in light of other threads. I have inherrited a tree that arrived with some leaf distortion and it will be interesting to see if my regieme of holding off food until late spring will cure it.

Again great post and it is always good to understand the logic behind good practices.

Joe.

Jow wrote:Intersting what you say about the blights in light of other threads. I have inherrited a tree that arrived with some leaf distortion and it will be interesting to see if my regieme of holding off food until late spring will cure it.

Hi Jow,

Just wondering how you ever went curing your leaf distortion? Did this method help or did you find another cure?

Cheers,
Pearcy.

Sent from my SM-G920I using Tapatalk