The most profound paragraph I've read here.

[Mike Corazzi]

The title of the thread is "Repotting a big maple" and the author is Walter Pall.

I'm sure MANY of you don't need to remember this, but I do. I'm going to make a condensation my sigline. This is the paragraph:

"If you repot in spring there is no foliage yet to help the roots to grow, the tree must do this out of stored energy. The energy was stored for foliage growth and not for root growth and the tree will be weakened. The foliage in spring will grow into an environment which gets worse every day, days longer, temperatures higher, humidity lower every day. The foliage will find it hard to grow well. It will quickly be too much to be supported by the existing roots - especially if you have cut off many. You have to cut short very soon after the shoots have stretched in order to avoid too much foliage mass which cannot be supported by the roots. The tree is weakened all the time by these measurement. It has a tough first summer after repotting. After two years the same again and people wonder why their trees are not doing well,m why thy do not get anywhere and stagnate."

Well DAMN! How logical. Me, I've been one of the dopes in the "leaves are on top, roots are on the bottom" brigade. Yeah, I ....think.... I may have known it prior to reading, but it just didn't sink in.




So now to keep me on the dime, I'm putting it in my sigline.

 

[PA_Penjing]

Absolutely can't argue with the logic there. But we need to remember that our summers are much hotter than Walter's. Especially you, Mike. I can't grow larch in my garden like Walter and I KNOW you can't either. It works well for him but I wonder when is ideal for us. Granted we'd probably have different answers between the two of us

 

[Mike Corazzi]

Absolutely can't argue with the logic there. But we need to remember that our summers are much hotter than Walter's. Especially you, Mike. I can't grow larch in my garden like Walter and I KNOW you can't either. It works well for him but I wonder when is ideal for us. Granted we'd probably have different answers between the two of us

That's correct.
I don't follow his procedures EXACTLY..
I add a ....sprinkle... of GOOD potting soil on the roots when I repot so they have something wet to welcome them to the lava and pumice.
I also put a BIT of it into the mix on some deciduous precisely because of the hellish heat we get here.

But, by and large I have to remember the timing of the leaf/root relationship.
I know I'd worry a lot less about bud break if I left trees in the pots more than a year.

Whadda.... I .... been doing? Well, every spring, cut back all the energy when there's no leaves.

duh.

 

[MrWunderful]

I would love to see the evidence behind “The energy was stored for foliage growth, not root growth”. The tree can subdivide and differentiate energy?

I myself never believed in the fact that “roots store energy”, I always thought it was just a function of the entire vascular system. The sugars and starches are stored in cells, not specific parts of the plant. But maybe I am wrong.

 

[Bnana]

The energy, in the form of starches and sugars, can only be used once. So the energy used to grow roots can not be used for bud development. It is not allocated but a simple trade-off.
Normally a tree does not have to do substantial root growth in spring and will use the stored energy to make leaves. root growth follows later in the season, using the energy supplied by the leaves. So the sentence makes perfect sense to me.

 

[leatherback]

I myself never believed in the fact that “roots store energy”

It is not true either. Energy is stored throughout the living cells in the tree.
The main concern is, do roots regrow fast enough if you have a fast heating up of the weather. Normally, roots are a few weeks behind on the buds. That being said, I often find growing roots when I repot.

I doubt that the intense type of rootwork to be done on trees early in their training are handled that well under hot summersun though. I mean..

The foliage in spring will grow into an environment which gets worse every day, days longer, temperatures higher, humidity lower every day. The foliage will find it hard to grow well. It will quickly be too much to be supported by the existing roots - especially if you have cut off many

How does that compare to mid-summer?

I have been repotting in every month of the year. I have yet to see a clear benefit from doing it in one specific time of year. But invasive rootwork, removing 90% or so, I do not thin I will ever be tempted to do this in summer.

 

[Mike Corazzi]

The thread in my OP was based on a Walter Pall thread of potting a big maple.
He removed very little around just the edge of the removed root "pancake.'
He was doing it in August. If the date of the thread indicates anything.
and in GERMANY!
He stressed sprinkling the foliage even there. after the potting. And removing no leaves.
I can't do what he did here. The point was that I learned why he doesn't pot only in the spring.
I repot every year which I think is too often. This year I have put all the trees in larger ventilated pots so I don't HAVE to do repot so often. I can see why letting some growth happen without disturbance would be good. Like ground grow but in a pot.

 

[Bnana]

Walter Pall doesn't say the energy is stored in the roots. In late August in Germany it's cooling down already. That would be safe especially if you leave most roots like in this example.

 

[Vance Wood]

I would love to see the evidence behind “The energy was stored for foliage growth, not root growth”. The tree can subdivide and differentiate energy?

I myself never believed in the fact that “roots store energy”, I always thought it was just a function of the entire vascular system. The sugars and starches are stored in cells, not specific parts of the plant. But maybe I am wrong.

It is kind of like the old--- if the world was round we would fall off of it---argument from five-hundred years ago.

 

[Djtommy]

I think that for good root growth it needs to be warm, in colder areas in japan, late summer repotting for maples and others happens more often then in warmer areas as far as I have seen. Spring in cold areas are a bit unpredictablue and this can have a big impact. When
repotting in summer there is no fear of cold spells so safer in that regard.

 

[Paradox]

Smells a fight brewing

*backs slowly out of thread*

 

[Bonsai Nut]

The title of the thread is "Repotting a big maple" and the author is Walter Pall.

Pause for a moment and make sure you are attributing his comments to his situation. A large maple bonsai in established soil in Bavaria. Everything he is doing, for where he lives, makes total sense.

If you live in Houston... humidity declines in the summer? I don't think so In NC, I almost don't need to water my trees in summer at all, because I get sub-tropical rains every other day. Without putting words in his mouth, he is saying make sure you balance the root work with the foliage growth. Don't reduce the root mass... then reduce the foliage mass... until the tree weakens until the point of no return.

 

[Adair M]

Walter’s “theory” also totally neglects the science of how trees grow! New growing foliage produces the hormone auxin. Which is sent down to the roots. It acts as a signal to the roots that there is lots of growth occurring up top. This signal stimulates roots to grow. If you pinch the new growth, this inhibits root growth.

This is why root pruning in spring makes sense. Sure, we cut off feeder roots. BUT, in spring, there’s active new growth, right? The new growth produces lots of auxin. High auxin levels stimulates root growth. So, the root ball is stimulated to replace those roots that were removed.

 

[Brian Van Fleet]

Yep, following that logic would result in disaster here...or did, actually.

Late Summer Repotting experiment

As an experiment to test the viability of repotting in the summer, when leaves aren’t growing, and roots are, I repotted a Japanese Black Pine, and a Japanese Maple. The pine had been in that…

nebaribonsai.wordpress.com

The maple is long dead, and the pine is just hanging on.

 

[Mara of dragon clan]

If I recall, Walter states that repot doesnt mean bare root, as well as aftercare being a key factor

 

[thatguy]

Great article by Brent over at Evergreengardenworks regarding auxin, cytokinens and how it all plays into plant/root growth. Worth a read: https://www.evergreengardenworks.com/pruning2.htm

 

[just.wing.it]

I wish humidity decreased as summer progressed here.....sheesh!

 

[Forsoothe!]

I don't do heavy work on the roots at the same time that I do heavy work on the top. I do my repotting in late May and June after the new canopy has matured and most of the growing season remains so there's plenty of time for replacement. If I repot and reduce the roots I do next to nothing on the top on the theory that roots are used to restore the canopy lost, and/or the canopy is used to restore the roots lost, so one or the other restores faster if left intact. I denude the deciduous in late June including removing all terminal buds for ramification and reducing the size of leaves, but never cut back branches in a major way, I would do that in autumn so buds lost could be redirected elsewhere in winter. The best growth comes in the second year following repotting (without denuding), so if you repot every year you have room to grow, but sacrifice intense growth that comes from having all its undisturbed resources available. The same principle applied to the canopy would be maximum growth of ramification but tip pruning all terminals in June, but not denuding which would redirect second flush growth as interior growth with no loss of existing canopy leaves or canopy size.

So there's my theory, and I'm sticking to it.

 

[sorce]

Walter’s “theory” also totally neglects the science of how trees grow! New growing foliage produces the hormone auxin.

You talking about auxin has been like a young lad who just found his pinus.

Trees grow new foliage in fall too.
Even those that don't, grow new roots.

Auxin shmauxin.

Walter Pall is Latin for

Jealous Maker.

Sorce

 

[leatherback]

Walter Pall is Latin for

Jealous Maker.

Tree zauberer