Defoliation to promote growth an increase trunk size?

[sheepdawg]

Hi everyone,

This is something that has been playing on my mind for awhile now and I want to see what other people think.

I currently have a small fig plant growing out (in the ground) to eventually become a bonsai, so basically I want to get that trunk as thick as possible. Because of this I've just been leaving it do it it's thing, but getting ready for summer has got be thinking. If I defoliate the whole plant, but leave the buds intact (and the leaf or two closest to the bud) will this help thicken it up quicker?

My thinking behind this is that by removing the leaves, the plant is forced to replace them. Since all the buds were left, it won't backbud (much) and it'll push out loads of growth from these buds, elongate the branch, and therefore thicken up the branch and trunk.

Thoughts? Would doing something like this actually help increase the rate of thickening?

Also, this thinking has mainly been about figs as I don't think this technique would work with deciduous stuff.

[DustyRusty]

There are different ideas about what defoliation is for but I've never heard anyone argue it thickens trunks or branches. Leaves provide the plant with its energy so removing them stalls the growth. Branch/trunk length is relative to thickness, so the longer the branch/trunk the thicker it will need to be. If you want thick give the trunk/branch unrestrained growth - don't prune or defoliate.

Defoliation is often done to reduce leaf size and its therefore good in the final stages of a trees development. Personally I do it simply so I can see the branches in preparation for a rewrite and prune. But I wouldn't do it at all if I had another way of seeing all the branches.

Good luck with the tree

[sheepdawg]

There are different ideas about what defoliation is for but I've never heard anyone argue it thickens trunks or branches. Leaves provide the plant with its energy so removing them stalls the growth. Branch/trunk length is relative to thickness, so the longer the branch/trunk the thicker it will need to be. If you want thick give the trunk/branch unrestrained growth - don't prune or defoliate.

Defoliation is often done to reduce leaf size and its therefore good in the final stages of a trees development. Personally I do it simply so I can see the branches in preparation for a rewrite and prune. But I wouldn't do it at all if I had another way of seeing all the branches.

Good luck with the tree

Like you just said, the longer the branch the thicker it will need to be. And that's the logic I'm working with. If I force the branch to grow longer that will make it thicken the whole plant up quicker. And to force the branch to grow quicker it must replace its leaves with the sugars stored in its roots.

[treeman]

Removal of any part of any tree at any time will reduce growth rate.

[shibui]

I see 2 probable false assumptions in this:
1.

the longer the branch the thicker it will need to be

Not necessarily. I've seen lots of long, thin branches and plenty of short, fat ones.
2.

And to force the branch to grow quicker it must replace its leaves with the sugars stored in its roots.

Who said sugars are stored in the roots? I thought plant nutrients are stored throughout the plant - leaves, branches, roots.
Like treeman just said: removing any part of a plant removes valuable nutrients and slows growth.

[Ces]

I'm passing on second hand information here, though I have tried the technique described I essentially forgot to take notice of the results as compared to other techniques.

Japanese trained, American bonsai artist Peter Tea described a similar technique for fattening trident maples. Remove all the leaves on the sacrifice branches and leader except for the final few pairs. These remaining tips are now presumably quite high up in the tree and drawing strength in apically dominant trees. They are then prioritised and elongate and thicken faster. Also, as the OP has suggested, energy that would have been directed to side branching on this stripped shoot goes into lengthening and thickening the shoot. That was Peter's explanation anyway.

I think this applies mostly to long suckers and leaders that have little or no side branching, just opposite pairs of leaves to the tip (i.e. like a whip used for grafting). Cutting off thick branches with further ramification and branching in order to only have the final few terminal leaves on one branch line would likely reduce the energy available to the tree in a detrimental way as others have suggested.

As I said, I did try it but I try heaps of silly things and this one I didn't really follow up so I cant report just quote

Hope this helps.

Cheers,

Ces.

[Ces]

wait... just read the original post again.

Peter's technique applies to sacrifice branches and leaders only. I don't think defoliating the whole tree except the terminal buds would produce what you are after.

That is my opinion not a quote

Cheers,

Ces.

[Jarad]

More leaves, more food, more growth.

No leaves, no food, no growth.

Why would you want to deplete the trees stored food? It will just have to replenish it's stores and then think about pushing new growth.

::EDIT::

You now know what people on here believe will happen, why don't you give it a go and see what happens?

You've asked a similar question before about trimming the end of a branch or something.

::EDIT2::

...maybe that was Homer

[anthonyW]

One of the quickest ways to get a fat trunk in a very short time is sacrifices.

Seed grown figs most of the time get natural base flare but of course that can take time...but the flare and taper will eventually come....cuttings not so much...so in leaving foliage on and the right foliage using sacrifices we can accelerate by many fold.

These cuttings that were one to one half inches when I started are now 8,10 and 12 inch figs 4 to 6 years later,yes quite quick growth using sacrifices the right way,starting with our main ones at the bottom and other hacks above helping to form taper and growth and leaving our apex to grow...the apex will be the only growth that will constantly cut back and let grow as it will always want to dominate,so we cut back so not to stall sacrifices and to help throw us more hopefully fluky shoots that will in time replace spent hacks /sacrifices,the bottom ones will always stay until we build...but remember you will always leave an apex even when we cut back and forth.

My main sacrifices are grown 8 to 12 foot,yes I am in a hurry LOL

Once we are happy with our trunk in making we cut the last of the sacrifices off,flat cut the trunk,wait for many shoots at cut top.pick one then angle cut if you want and the grow top up and down for taper.DO NOT angle cut at top before shoots,as you will not most of the time get it where you want to start trunk.

Of course scars are the trade off,when attending cut, put a nice sharp edge around the cut clean out 3 to 5mm inside the cut then it should roll over more adequately.

The great bulk of the trunks are sitting on wide flat dishes to get root age going laterally.

So there you go foliage is important in the right places if used correctly....good luck

Cheers Anthony

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Tiger in action

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PJF cut down waiting the next step..I like the taper here

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PJF time to build

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Where it sits today and building

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More Tigers,note the sacrifice giving width to the one on the left

[sheepdawg]

After re-reading a section of my old uni text book, I am convinced I am right. I may be new to bonsai but that doesn't mean I can't be right and the experienced persons can be wrong.

When I defoliate a developed ficus bonsai, it replaces its leaves from energy stored in its roots (primarily). The plant takes a bit of a hit but is fine in a couple weeks. One of the things I've noticed when defoliating, is that removing the end growing shoots is essential to get the dormant buds along the branch to break and grow. Basically, if I defoliate a branch and leave the end growing shoot, I won't get many bud breaks and therefore any "branching". Because all the growth for that branch is put into the end bud. This makes sense academically; because this end bud produces a hormone called auxin which inhibits bud breaking as it travels from the shoot to the ends of the roots.

In addition, a hormone called cytokinin is produced in the roots of the plant and travel upwards towards the tips. Cytokinin is passively transported through the plant's water stream (the xylem). This hormone specifically promotes cells to move from their G2 phase to their M phase (the G2 phase is a "gap" phase where the cell basically grows. The M phase is the mitosis phase, where the cell actually starts to divide). Basically, it promotes cells to divide which is basically "growth".

Now, how does this relate to defoliation? If the end bud is removed no auxin is being produced and therefore many buds break and grow because they aren't being suppressed anymore. Cytokinin's involvement is a little more limited because it travels to places where water is being lost.

So, how does this relate to what I originally asked? Well, when I remove the leaves cytokinin travels to the places where water is being lost. The only places left on the plant is the end buds. Before there were many leaves that absorbed this cytokinin but now it collates in the end bud. This means more cytokinin than ever before collecting in the bud. More cytokinin=increased levels of cell division promotion=growth at the end.

BUT! You may ask, "how does this encourage trunk thickening?"

The thickening of a plant's trunk/branch/whatever is called Secondary Growth. Secondary Growth is the result of activity in the two lateral meristems of the plant. The two later meristems of the plant are the vascular cambium and the cork cambium.

The vascular cambium is a plant tissue that produces the xylem and phloem of the plant, which transport water, minerals, and food throughout the plant. The cork cambium is responsible for producing the cork of the plant (it's most outer protective layer).

So, to get Secondary Growth we must get encourage the production of the xylem, phloem, and cork. Now, how do we do this? With new growth of course!

Essentially what happens is that removing the leaves of the plant means that more cytokinin reaches the growing bud. Because more cyctokinin is getting there, there is a greater stimulation of growth. The greater growth means more xylem, phloem and cork is being produced which means greater Secondary Growth.

Now to address what some people have said:

"Who said sugars are stored in the roots? I thought plant nutrients are stored throughout the plant"
True, but sugars are primarily stored in the roots of woody trees. Especially figs! That's why they swell and produce that kidney shape, it's stored water and starch.

"Why would you want to deplete the trees stored food?"
To thicken the trunk quicker... This is the whole point.

"It will just have to replenish it's stores and then think about pushing new growth."
It can't replenish its stores without putting out new growth.

[sheepdawg]

To add to what I just wrote: a few leaves (or even thousands of leaves) sitting on a branch will never thicken that branch. Why? Because the lateral meristems are not active.

[Rory]

From my experience, and I've had figs on and off since about '96, if you cutback anything it slows it down.
I admire that you are stubborn and strong willed in your beliefs.

My advice is to not overly preach your theory until you've proven it.
For example, Darwin didn't release his theory until he had the proof and evidence documented to back up his theory.

Your science sounds flawed to me, primarily from years and years of experience.
Test your theory if it is something you want to proclaim to an entire community.
I would take 50 fig seedlings all same size, and grow half of them with your theory and the other half left alone.
Grow them all in same conditions, same root space / ground grown /sun .

After many years of documenting the tests then produce your theory and results.

This is what I did with species that tolerate strong shade and I used many more seedlings than that.

I can see you've done a lot of research, and whether you are right or wrong isn't going to be concluded with horticultural jargon. I mean this in a constructive way.

Good luck, but just make sure it's something you want to invest time in, and/or is it greatly going to benefit you vs the effort required vs simply ground growing and forgetting about them for a few years.

[Tambrand]

Ficus, sacrifice branches and a 1" [ 2.5 cm ] deep pot in images.
Tambrand

Local Ficus primioides [ spelling ?]
Collected - 1st year

[Tambrand]

3rd year of growth

[Tambrand]

4th year and sacrifice branch - idea is a 3" [ 8 cm trunk ]