Opinions on when a tree is mature enough to pot

[badatusernames]

I did a few searches and was surprised not to find anything, I apologize if this has been beaten to death previously.

I feel like I'm a little unclear on a couple aspects of potting. I recognize there are an array of opinions, so I won't ask for any definitive answer, but I'm curious how people think about when a tree goes into a pot.

The reason I ask is because I always thought that as a best practice - like, top tier, it's your job style - they basically lived in boxes until showtime, and then after the show, back into boxes they went. As hobbyists, we probably aren't doing that.

However, in a glazed pot, my understanding is that growth is stunted (that being part of the point), and so thickening should be done in grow pots. Once the trunk is as thick as you're going to want it, primary branches as thick as you're going to want them, and the tree is moving into refinement, you can put it in a glazed pot. That's as I understand it.

I do however see a lot of very talented people seeming to grow substantial parts of the tree out in pots - this one is just an example:



I would have thought this is somewhat early.

For comparison, here's a pomegranate I've abused and currently in the process of allowing to hopefully recover - bad time of year for it I suppose, but am hoping with the lights that I could try this out. There's that peeping leaf and lots of buds, I think it lives, at least!



Now, I had popped this in here as a placeholder thinking I'd move it to a grow pot next year - thinking, really, that I'd have to in order to get it to really go nuts. Now I'm questioning myself, and wondering if the thickening of branches/healing of wounds in glazed pots is considered at least a reasonable if not best practice? The linden is certainly a different caliber and maturity of tree, but I sort of would have thought even this would be a tree that most would advise to put in a grow pot, so I want to make sure I'm clear on it. I think it's very possible the linden is far more advanced that I'm thinking it is, I know he spoke about cutting branches at the length you want them and building taper back from there rather than trying to grow taper out from shorter branches to fit a wider profile.

Further, a sub-question about pot materials that I want to ensure I have clarity on. My understanding is that glazed pots are the most restrictive in terms of allowing a tree's free growth (oxygen exchange through the glaze, something like that). I thought unglazed, however, allowed a tree more oxygen and was, if it were the same size as a grow pot, essentially be a grow pot. So would these two pots be accomplishing the same thing?

Or would terracotta allow for more oxygen exchange and be the better vessel? Would you consider that a good option for growing out the maple on the left, or would you be more inclined to put it in a box or an Anderson flat, assuming you were roughly happy with the height and going for something a little more graceful than squat and beefy?

This is all less about "can I get my trees into pots faster" (I mean, they're where they are for now, aren't they) and more trying to understand the specifics in a bit more detail.

 

[John P.]

Nice topic for a post.

 

[Wires_Guy_wires]

My idea of a tree being ready for a smaller pot is based on the trunk size.
When a tree is in a good soil and in a small pot, the length-wise (in all directions) growth reduces, and so does thickening speed. This allows you to get good control over branches and ramification. Wounds stay smaller because cuts are smaller, internodes get shorter because growth is reduced, thickening is slower because growth is reduced. I think that's refinement in bonsai terms.

I have a couple pines that are super apically dominant. Their pot is too big! The branches go from millimeter twigs to large-pencil-thickness within a year. About the same girth as the trunk. Withholding nutrients does help, but a smaller pot would push it harder to produce smaller and shorter growth as well.

When the best timing would be, I think, would be when you have a profile set and are ready to fill it in. But this too is something species dependent.
I prefer putting them in small pots too soon, I have time - and I'm fine with looking at sticks for 10 years instead of 2 - and I dislike large wounds.

Glaze or not, a good soil and watering habit can fix a lot of things. Some plants don't give a hoot about a bit more or a little less oxygen in the soil.

I guess that there are many opinions and takes on what's efficient, what's best, what's OK and what's worse. There are many roads to Rome. I take the long road for some, and ground or box grow others. I like to experience the difference for myself and see what suits me best. That's why I have at least two or more plants of every type.

 

[Potawatomi13]

1. When tree has big as desired trunk. Small pot guarantees small trunk!
2. AND is far enough in development to be at refinement stage

Any time after reaching this stage.

Waste of money on fancy pot on tree not ready for display is!

 

[leatherback]

I do both.

I grow some stock out in overly large plastic "bulb pots" or even shallower, trays that are used to catch water under large pots. These get to beef up fast and once primary branches are set I will put them into a nicer pot.

However, I am also growing out a number of cuttings / seedlings in "nice pots". These will be very slow to thicken. However, I am growing them as bonsai, allowing major extension growth in the first 2/3 of the year, cutting back mid-summer and getting "keeper branches" in late summer, wired in fall ready for next year.

I believe the best quality bonsai are grown like that. Slow and steady, instead of the 5-year rush for a big chopped trunk.

Middle ground it to buy cheap large nice ceramics and upgrade as the tree reaches a decent maturity.

Plastic growing out:


Large ceramic growing out:


Very shallow plastic growing out.

 

[penumbra]

My understanding is that glazed pots are the most restrictive in terms of allowing a tree's free growth (oxygen exchange through the glaze, something like that). I thought unglazed, however, allowed a tree more oxygen and was, if it were the same size as a grow pot, essentially be a grow pot. So would these two pots be accomplishing the same thing?

A properly made fully vitrified unglazed pot allows no more air to pass through it than it does water. It is the same as a glazed pot. Many people, probably most people believe conifers belong in unglazed pots and deciduous in glazed pots. I do not subscribe to this way of thinking.

Or would terracotta allow for more oxygen exchange and be the better vessel?

Terra cotta is not fully vitrified and does allow for more (still very little) exchange of gasses. It also will not last as long, particularly where there is a freeze / thaw cycle.

I could care less about who puts what in what as long as it suites their purpose.

 

[Brian Van Fleet]

No right answer, of course, but with your example JM in the terra cotta bulb pan, I would put it in a larger, shallow wide box for a few more years to develop the nebari and close those chop wounds. When the trunk wounds are healed, that’s when I’d put it in a bonsai pot.

The balancing act is between getting enough growth to close wounds and not so much that necessitate yet another chop to heal.

 

[Forsoothe!]

There's nothing wrong with training a tree in a nice pot. Roots need to be restricted to balance with the canopy, and if you are satisfied with the size of the tree and are refining the canopy, the process of matching the roots to a specific size & shape pot can take years and repotting during those years is part of the process. A tree "in-training" for 10 years is better than one in training for 5 years, and 15 years is even better, ad infinitum. You don't bother getting the canopy in top condition until after the tree is in a finished-pot size pot, and not many of us have ugly or non-show pots exactly duplicating the size & shape of our finished pots, so considerable training goes on when the tree is put into the show pot. The Japanese are different animals and are equipped to switch pots for show use only, and do that with special show trees that have been in that special condition for a long time. That's a much higher level of handling than most of the rest of us are up to.

Remember, the pot limits the growth of the tree and 100 year old trees are where you want them size-wise, they are just kept refined continuously with some exceptional in-between periods where they need to have parts replaced by new growth for the health of the tree, then they may be put into growth containers, but those wouldn't be much larger because you still want to control root size and not find yourself battling back to much smaller roots. Control is more important than just maximized growth. In fact, I'd bet that the Japanese look down on the western concept of maximum growth at any stage. You see in videos their growing areas have trees that fathers planted that are tended and replanted many times by sons, only to be finished and moved into pots by grandsons years in the future. Big trees, pefect taper, -virtually no scars. I'm sure the Japanese would tell us that if you don't have time to grow them on slowly you should take up something like basketball instead of pretending to be bonsaiists.

 

[Cajunrider]

I don’t have anything to add. Good topic O.P. Great discussion all. This topic is useful to me. Thanks.

 

[badatusernames]

No right answer, of course, but with your example JM in the terra cotta bulb pan, I would put it in a larger, shallow wide box for a few more years to develop the nebari and close those chop wounds. When the trunk wounds are healed, that’s when I’d put it in a bonsai pot.

The balancing act is between getting enough growth to close wounds and not so much that necessitate yet another chop to heal.

That makes sense! These terracotta pots are convenient from a size and storage perspective but I have a feeling I’m going to be doing more box building next year.

Would you be using a 1:1:1 mix in that scenario, or still some organics in the soil?

 

[Colorado]

The reason I ask is because I always thought that as a best practice - like, top tier, it's your job style - they basically lived in boxes until showtime, and then after the show, back into boxes they went.

I don’t think this is true at all. Bonsai pots serve an important purpose: constriction of the root system. It is going to be very difficult if not impossible to bring a tree into refinement into a big grow box.

We forget that root constriction is an important part of refinement.

 

[badatusernames]

I don’t think this is true at all. Bonsai pots serve an important purpose: constriction of the root system. It is going to be very difficult if not impossible to bring a tree into refinement into a big grow box.

We forget that root constriction is an important part of refinement.

Oh interesting! I thought I had heard that! Sometimes it’s hard to even ask a question without potentially spreading disinfo, I guess.

 

[Carol 83]

I have trees in nice pots that don't really deserve them. My trees, my pots. Bring on the Bonsai police!

 

[Brian Van Fleet]

That makes sense! These terracotta pots are convenient from a size and storage perspective but I have a feeling I’m going to be doing more box building next year.

Would you be using a 1:1:1 mix in that scenario, or still some organics in the soil?

I don’t use organics as part of my soil mix, but you certainly could use pine bark (sold here as “soil conditioner”) and lava rock.

 

[sorce]

It's more important to note the condition/maturation of the root mass over the tree itself. Also understanding the relationship between the 2 and how this translates to specific goals.

There are so many odd bits of information in regards to this, it's hard to compile information in a way that it would make sense, this is a good starting point.....

We forget that root constriction is an important part of refinement.

This is kinda correlation without causation.

We may correlate a proper constriction with a small pot, but the cause of proper constriction has more to do with previous soil/pot/work combination, that determines the type of roots being constricted.

I think it's easier to think of this "constriction", which has been semi-debunked, as this "freezing" of the Nebari, which is truly caused by a system of feeder tips that can supply the tree so well, they do not need to revert to "thick running" roots anymore. (think the ones that push trees up out of pots) Those roots are mostly useless and can be detrimental to aesthetics I'm early development.

I believe the fastest way to this frozen feeder system is with the use of air pruning containers. This step should/can be utilized in place of many risky repots and root trims during development and adds the benefit of lessening the need for highly invasive repots later as well, because there is no need for the roots to shoot in search of a better environment to grow feeders, so it stays frozen, "constricted".

Trees are opportunistic and very smart, they won't waste energy on tissue they don't need, most importantly, they give absolutely no eff about our need for beautiful aesthetics.

Take a newly hacked and barerooted D with one string of feeders and one fat ready bud, stick it in a small pot with potting soil, and you'll likely end up with one large shoot and one large root.

Take the same tree, cut that last feeder string and bud off, put it in loose soil in a small pot, and you are more appropriately constricting.

Brings up this idea that "loose soil", actually acts as a root pruning system itself, where tips will die between watering, leading to a continuation of fine feeder roots.

So the range is between these extremes of, a large pot with a small tree, undeveloped root system and thick soil, and a well "feedered" large tree in a small basket with loose soil.

So many points between those extremes that can be utilized to achieve different developmental goals at different stages.

Like utilizing my hybrid "basket+ground" system when developing large trunk sections.

Once one realizes the actual benefits of a proper root pruning container, not the large BS surrounding "colanders", one can see how grow boxes are rather foolish.

We know that the "*sweet spot" of any container is the warm outer most edge of any container.
We know that oversized pots aren't recommended.
So our "larger" grow boxes, though useful in their "not oversized", still grow most of there best roots in a place* that will require removal to for into that slightly smaller ceramic development pot.

All of those feeders and more can be contained and kept within a proper airpruning container a size equal to the future ceramic, without need for invasive rootwork at all upon repotting. This is the only place slippotting is absolutely appropriate for bonsai.

Sorce

 

[Colorado]

It's more important to note the condition/maturation of the root mass over the tree itself. Also understanding the relationship between the 2 and how this translates to specific goals.

There are so many odd bits of information in regards to this, it's hard to compile information in a way that it would make sense, this is a good starting point.....



This is kinda correlation without causation.

We may correlate a proper constriction with a small pot, but the cause of proper constriction has more to do with previous soil/pot/work combination, that determines the type of roots being constricted.

I think it's easier to think of this "constriction", which has been semi-debunked, as this "freezing" of the Nebari, which is truly caused by a system of feeder tips that can supply the tree so well, they do not need to revert to "thick running" roots anymore. (think the ones that push trees up out of pots) Those roots are mostly useless and can be detrimental to aesthetics I'm early development.

I believe the fastest way to this frozen feeder system is with the use of air pruning containers. This step should/can be utilized in place of many risky repots and root trims during development and adds the benefit of lessening the need for highly invasive repots later as well, because there is no need for the roots to shoot in search of a better environment to grow feeders, so it stays frozen, "constricted".

Trees are opportunistic and very smart, they won't waste energy on tissue they don't need, most importantly, they give absolutely no eff about our need for beautiful aesthetics.

Take a newly hacked and barerooted D with one string of feeders and one fat ready bud, stick it in a small pot with potting soil, and you'll likely end up with one large shoot and one large root.

Take the same tree, cut that last feeder string and bud off, put it in loose soil in a small pot, and you are more appropriately constricting.

Brings up this idea that "loose soil", actually acts as a root pruning system itself, where tips will die between watering, leading to a continuation of fine feeder roots.

So the range is between these extremes of, a large pot with a small tree, undeveloped root system and thick soil, and a well "feedered" large tree in a small basket with loose soil.

So many points between those extremes that can be utilized to achieve different developmental goals at different stages.

Like utilizing my hybrid "basket+ground" system when developing large trunk sections.

Once one realizes the actual benefits of a proper root pruning container, not the large BS surrounding "colanders", one can see how grow boxes are rather foolish.

We know that the "*sweet spot" of any container is the warm outer most edge of any container.
We know that oversized pots aren't recommended.
So our "larger" grow boxes, though useful in their "not oversized", still grow most of there best roots in a place* that will require removal to for into that slightly smaller ceramic development pot.

All of those feeders and more can be contained and kept within a proper airpruning container a size equal to the future ceramic, without need for invasive rootwork at all upon repotting. This is the only place slippotting is absolutely appropriate for bonsai.

Sorce

Well that is your opinion. I don’t think it is “correlation without causation.” I agree with you that there are more variables than just pot size. But a smaller container - I.e. a bonsai container - will absolutely be a cause of a tree having less vigorous - I.e. refined - growth habit. In my opinion.

 

[sorce]

I don’t think it is “correlation without causation.”

"Kinda" is important.

It absolutely can be and can not be, depending on so many other factors.

Sorce

 

[sorce]

Well that is your opinion.

To be more clear I guess ....

There is no opinion there. "Kinda" indicates that.

I believe what we do as "correct" in general, leads us to a place where 90% of the time it is direct causation, which is why I agree with you.

It's this 10% of "impossible to make exact causation", that sheds light on the fact that addressing the state of the "feeder mass" or what you are "freezing/constricting" becomes more important to pay attention to.

In that, "twiggy roots make twiggy branches".

Which is more true than, "a small pot makes small branches".

Though one could "force" the opposite, I think that is working too far against the rythym of the tree.

Same as actually achieving the correlation 10% would be foolishly working against the trees rythym.

Somehow this is a more important conversation about this subject, than most of the traditional answers which have much more to do with opinions on design aesthetics.

I believe in understanding this information, folks can find the most efficient path to any of these subjective goals.

Specific situations for specific goals.

Root growth should be maintained completely different for say, a tree with a large chop to be healed or a tree with a large chop to be uro'd.

I think we swing too many broad swords. This leads to confusion in "it depends'. "Depends on what?"
Why are we afraid to get to that next level of sorting them all?

How about....

It Deepens!

Only our pots should be shallow.

Please!

Sorce

 

[leatherback]

My trees, my pots.

 

[leatherback]

In my opinion.

Not opinion. Fact. Biological fact.