Colander vs Terra Cotta?

JackHammer

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My understanding is that a colander can be used for pine trees in an effort to make the roots compact and fiberous enough for placement in a bonsai pot. Any roots that are near the surface of the colander will dry out and die back creating a dense root ball.

Doesn't terra cotta do a very similar thing? As long as the pot isn't soaking in a drip tray, the outside roots are generally dissuaded from growing too long due to the drying nature of terra cotta. I am under the assumption that the sun and wind on any given day would remove a significant amount of water from the sides of the pot, keeping the roots in a more compact fashion. Is this correct?

I am asking because the colander concept while valid, seems quite volitile. Even slowing the process slightly and working to capture similar results would likely allow for a less intense and more forgiving maintenance schedule. Is the trade off worth It?
 
My experience (non-bonsai plants but still) has been that roots actually like to wedge into the terra cotta looking for that escaping moisture and that the solid pot walls still allow for root circling. Plus then at repotting time you either have to cut all around the roots indiscriminately to get the plant out or you have to shatter the pot.
 
My experience (non-bonsai plants but still) has been that roots actually like to wedge into the terra cotta looking for that escaping moisture and that the solid pot walls still allow for root circling. Plus then at repotting time you either have to cut all around the roots indiscriminately to get the plant out or you have to shatter the pot.
Hmm. Could be. I will have to take a closer look at my vegetables when I re-pot them. I am wondering if there is a thinner type of terra cotta that exists. Maybe I should start manufacturing some.
 
If anything, terracotta will have the benefit of many feeder roots around the outside, due to it's retaining of moisture, which should keep thick circling roots to a minimum, but they will still exist.

Even a window screened colander will grow thicker circling than a terra Cotta pot for that reason. Since a screen lined colander will circle roots even being open. So a thin terra Cotta will too.

After studying pond stuff so much lately, hell, just listening to "gut health" ads lately, you see how we are just beginning to understand the relationship between bacteria and life.

People only talk about conifers and mycorizza because they found a way to isolate it for sale to ignorant @ucks, who are already removing the possibility of it occuring naturally, due to fungicides, which of course, they probably made available before now selling us the stuff that shit removes! Scandalous!

Anyway, they just don't know about the bacterias and fungis that deciduous trees use, because they haven't found a way to market it yet. They exist.

So the point is, the largest benefit of an appropriate airpruning device (not colanders they suck), is not having to disturb this ecosystem as often as with other pots.
A perfectly manicured matte of excellent feeder roots that a proper airpruning device creates, is just an added benefit.

Sorce
 
If anything, terracotta will have the benefit of many feeder roots around the outside, due to it's retaining of moisture, which should keep thick circling roots to a minimum, but they will still exist.

Even a window screened colander will grow thicker circling than a terra Cotta pot for that reason. Since a screen lined colander will circle roots even being open. So a thin terra Cotta will too.

After studying pond stuff so much lately, hell, just listening to "gut health" ads lately, you see how we are just beginning to understand the relationship between bacteria and life.

People only talk about conifers and mycorizza because they found a way to isolate it for sale to ignorant @ucks, who are already removing the possibility of it occuring naturally, due to fungicides, which of course, they probably made available before now selling us the stuff that shit removes! Scandalous!

Anyway, they just don't know about the bacterias and fungis that deciduous trees use, because they haven't found a way to market it yet. They exist.

So the point is, the largest benefit of an appropriate airpruning device (not colanders they suck), is not having to disturb this ecosystem as often as with other pots.
A perfectly manicured matte of excellent feeder roots that a proper airpruning device creates, is just an added benefit.

Sorce
You would like the book the Secret life of Trees. I am assuming that you have read it.
 
My understanding is that a colander can be used for pine trees in an effort to make the roots compact and fiberous enough for placement in a bonsai pot. Any roots that are near the surface of the colander will dry out and die back creating a dense root ball.

Doesn't terra cotta do a very similar thing? As long as the pot isn't soaking in a drip tray, the outside roots are generally dissuaded from growing too long due to the drying nature of terra cotta. I am under the assumption that the sun and wind on any given day would remove a significant amount of water from the sides of the pot, keeping the roots in a more compact fashion. Is this correct?

I am asking because the colander concept while valid, seems quite volitile. Even slowing the process slightly and working to capture similar results would likely allow for a less intense and more forgiving maintenance schedule. Is the trade off worth It?
The purpose for using a colander with pines is twofold.
1. To create a dense fibrous root system, as the root tips reach the mesh they are exposed to air thus the tips dry out and die. As the root tips die they produce finer roots branching off within the colander, these roots reach the colander mesh exposing themselves to air, root tips die, and the process repeats over and over. Finer roots = better intake.
2. Most pines prefer drier substrates. They like to get wet and then dry out. The mesh on the colander allows a thorough soaking and then can dry out for the next watering.

Terracotta pots do not do the same thing as colanders. They actually retain moisture as they get wet and then slowly release it as they dry like a sponge. Terracotta pots will not produce the same root system as a colander will. When the roots hit the inside wall of the pot they will then immediately begin to travel down along the sides until they hit the bottom. Once they hit the bottom they will just grow around and around. The roots in a terracotta pot will be predominately focused all around the inside wall of the pot, because that is where the moisture will be. This is the main reason why terracotta pots don’t survive hard winters as the moisture freezes within the clay and causes cracks.
 
I use terra cotta extensively for training pots and don’t intend to switch!
I'm not a fan of colanders......but pond baskets are useful when placed directly on the ground as the roots can easily enter the ground. You get the best of both worlds.
 
Why so cryptic? Care to share? 🤔

I have spoken of it before, the differences between the 3-5 totally different things we call "colander".

Just actual Colanders alone are produced in a manner that is either incompetent as a airpruning device, or unable to withstand more than a month of UV's.

So Colanders themselves are useless.

I'm not a fan of pictures I've seen of the bags, since while roots don't continue to grow, it looks like they form little balls at the end where the roots reach the fabric. I don't find trying to get that junk into a bonsai pot very useful, so it would have to be cut off. At least I wouldn't try jamming all those tips in a small pot, then you have wounds all over the rootmass. I don't consider these in the same category of device either, more suitable for ground growing I reckon, but not as a "proper airpruning device".

Screen lined baskets (adding screen inside a larger holed basket) of any manner are useless as actual proper airpruning devices too, since roots will circle around them as well.

I thought the most brilliant thing about the actual airprune pots, are the root funnels on the side.
This is the part of them that works to gather every root in the pot, yet it is the part that gets ignored when seeking anything else to use as a proper airpruning device.

That leaves us with Vance's boxes and my Training pots. The only designs that actually perform up to those airpruning pots standards.

With all this talk we do about the subject, I can't believe no one else has invested the time to make a bunch of either!

I consider proper airpruning devices a tool, because they are, a very specialized tool.

Using something that only works sometimes, is like installing trim with a sledge hammer, or trying to carve an ice sculpture with a blowtorch, mowing a lawn with nail clippers, or painting a house with a peeing horse. Sure it will work, but in this endeavor, where attention to detail is so necessary, we should pay more attention to our approach....maybe be aware of what we are actually doing...just a little.

A couple seasons in a good airpruning device leaves you with a rootmass that's almost irreversible. Near impossible to turn back into a bunch of useless running thick roots.
It leaves you a core of life support that can be easily transplanted into anything, even heavily pruned, since the core core is always enough FEEDER ROOTS.

Just because we can cut every piece of feeder root off of some trees, doesn't mean we should.

You ever get stuck in the ridiculous cycle of hitting restart on a video game if you die once, or miss a coin? Cutting every root off any tree is like that to me, except there is no "perfect game" to be achieved with a tree, we're just starting over.

Makes no sense, serves only as a setback.

There are no setbacks when using proper airpruning devices.

Sorce
 
Its been discussed to death but I am a fan of pond baskets and grow bags. I have never used colanders so I can't comment other than to say it makes no sense when pond baskets and grow bags are available. I also have many plants in terra cotta and in wood pots.
As to what I intend to do or not to do, well .... my father always told me the road to hell is paved with good intentions ...
 
I have spoken of it before, the differences between the 3-5 totally different things we call "colander".

Just actual Colanders alone are produced in a manner that is either incompetent as a airpruning device, or unable to withstand more than a month of UV's.

So Colanders themselves are useless.

I'm not a fan of pictures I've seen of the bags, since while roots don't continue to grow, it looks like they form little balls at the end where the roots reach the fabric. I don't find trying to get that junk into a bonsai pot very useful, so it would have to be cut off. At least I wouldn't try jamming all those tips in a small pot, then you have wounds all over the rootmass. I don't consider these in the same category of device either, more suitable for ground growing I reckon, but not as a "proper airpruning device".

Screen lined baskets (adding screen inside a larger holed basket) of any manner are useless as actual proper airpruning devices too, since roots will circle around them as well.

I thought the most brilliant thing about the actual airprune pots, are the root funnels on the side.
This is the part of them that works to gather every root in the pot, yet it is the part that gets ignored when seeking anything else to use as a proper airpruning device.

That leaves us with Vance's boxes and my Training pots. The only designs that actually perform up to those airpruning pots standards.

With all this talk we do about the subject, I can't believe no one else has invested the time to make a bunch of either!

I consider proper airpruning devices a tool, because they are, a very specialized tool.

Using something that only works sometimes, is like installing trim with a sledge hammer, or trying to carve an ice sculpture with a blowtorch, mowing a lawn with nail clippers, or painting a house with a peeing horse. Sure it will work, but in this endeavor, where attention to detail is so necessary, we should pay more attention to our approach....maybe be aware of what we are actually doing...just a little.

A couple seasons in a good airpruning device leaves you with a rootmass that's almost irreversible. Near impossible to turn back into a bunch of useless running thick roots.
It leaves you a core of life support that can be easily transplanted into anything, even heavily pruned, since the core core is always enough FEEDER ROOTS.

Just because we can cut every piece of feeder root off of some trees, doesn't mean we should.

You ever get stuck in the ridiculous cycle of hitting restart on a video game if you die once, or miss a coin? Cutting every root off any tree is like that to me, except there is no "perfect game" to be achieved with a tree, we're just starting over.

Makes no sense, serves only as a setback.

There are no setbacks when using proper airpruning devices.

Sorce
This is very informative and I appreciate your through response!
 
I love terra cotta because my fungi love terra cotta and my pines love fungi.
I can lift my pines at the trunk and get the soil out in one piece because the fungi hold it together.
Wood is a good second best.
Collanders have a third place.

I'm not a fan of bags because they're not stable enough. Nonetheless I have 70+ seedlings in bags. They're cheap as dirt!
 
I guess Markyscott and Jonas (Bonsai Tonight) to name just two are just wasting their time using those useless colanders and pond baskets. From the little I have read I think that the main issue with having lesser results with colanders is that people tend to treat the trees as if they were in a regular pot. According to Jonas, when you use a colander you have to water more, and fertilize more as well.
 
Colanders are somewhat over rated. I prefer pond baskets, as they are UV stable. AND I do have a couple @sorce made training pots with their gutter leaf guard mesh sides and concrete bottoms. And they are stable, difficult to get blown off a bench and if they do fall, the concrete always lands first, the tree usually survives the drop.

Terra Cotta is nice, in that mycorrhiza do love it, BUT, Terra Cotta is not freeze-thaw resistant, if I were to use it, pots wintered outdoors (which is 90% of my trees) would end up with cracked and broken pots, meaning every terra cotta pot would need replacement with spring repotting OR duct tape to hold the pot together if the tree needs to go 2 seasons without being repotted.

Pond baskets and Colanders are also a hazard if you are like me, and are not always able to water your trees daily. They dry out rapidly, leaving no "margin for error" much less a long weekend. Great if you have an automatic watering system, bad if you only water by hand. Any deciduous in pond baskets in my collection have perished quickly. Right now I only have a couple pines in pond baskets.

JWP are intolerant of being too wet in winter, here pond baskets are ideal.
 
Just actual Colanders alone are produced in a manner that is either incompetent as a airpruning device, or unable to withstand more than a month of UV's.

So Colanders themselves are useless.

Fake News! Not true in my experience. Uv is an issue after three years in my climate. Color change and more brittle. They cost $1 and serve their purpose until a larger size pond basket or an Anderson flat is needed. They do not cause roots to circle, they do air prune roots effectively! The caveat being that I am using inorganic free draining mix with all my containers. They do need carful watering due to the free drainage. You can get a better deal from the dollar store if you purchase by the case. The type I use come 48 per case and I have successfully used them for decades to raise pines. One year on the bench to establish root form and then set them for three years in the grow beds, Simple matter to cut off escaping roots and retain the core root ball. This method matches the seedling radial cutting process and develops even nebari from the outset. They are cheap, ugly and break down. But they work for their intended purpose which is to create better shape and type of roots from the outset to improve the overall outcome. ( assorted applications pictured below post
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For deeper root balls and longer periods of air pruning the pond baskets are an improvement over colanders. They also stand up better under UV, typical useful like of ten years in my experience. Higher cost so they are not a cheaper alternative than colanders. I use these primarily for species that need deeper substrate and benefit from a larger container. Examples would be Chojubai, Prunus Mume, Toyo Nishiki.
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Terra cotta can be used but does hold more moisture and cracks if climate is colder. It helps to use terra cotta that has been produced with more care and higher temperatures. I have had best experience with " Deroma" brand from Italy. They also come in a more advantageous shape shorter and wider for developing bonsai root balls. Typically referred to as Azalea pots or bulb pots. Terra cotta must be watered carefully as they stay wet for much longer periods of time. Easily develop algae on the outside and keep the roots too wet unless allowed to dry out between waterings. Actually the terra cotta holds the moisture longer and the inorganic mix can dry out before the terra cotta making it difficult to judge water levels within the pot. I do not recommend them for pines for this reason. I prefer them for deciduous that are ok with more continuous damp conditions. Great for establishing dwarf maples, Azalea, Zelkova, hornbeam, persimmon. I find it best to drill additional drainage holes and cut slots to improve drainage in terra cotta
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Anderson Flats have the disadvantage of drainage impeded when put on a flat non porous surface. best to drill a few holes low down on the side to allow drainage when placed on a solid surface. The alternative I choose is to set them on a rougher or slotted surface. Typically a larger size gravel base.
I find these ideal for Pines and also Maples due to their shape and size. Have to adjust the soil mix to retain appropriate levels of moisture for the species.
The side holes really help drainage and they can be nest for additional drainage in special situations.

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Note: all of these containers are used for development purposes and I am not suggesting them as replacements for Bonsai pots once the trees are finishing development and entering refinement.
 
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