Colanders and mesh; hold your roots!

[Clicio]

So colanders, pond baskets or grocery store plastic baskets are very good for bonsai in training.
One school of thought says "the roots get automatically air-pruned by light and dryness"; the other says "light by itself will not kill roots"; so air pruning means roots getting their way out of the pot by its sides and botton small holes, and dying of some kind of exposure.
Alright, but...
WHY do many pictures in several threads show the colanders with fine mesh inside, covering the holes? (Yes, I suppose it's to hold the soil inside)-if with the mesh inside the roots have no chance to "escape"?
To mesh or not to mesh?

 

[BrianBay9]

Holes in the colander are too big and let soil leak out?

 

[Rodrigo]

So colanders, pond baskets or grocery store plastic baskets are very good for bonsai in training.
One school of thought says "the roots get automatically air-pruned by light and dryness"; the other says "light by itself will not kill roots"; so air pruning means roots getting their way out of the pot by its sides and botton small holes, and dying of some kind of exposure.
Alright, but...
WHY do many pictures in several threads show the colanders with fine mesh inside, covering the holes? (Yes, I suppose it's to hold the soil inside)-if with the mesh inside the roots have no chance to "escape"?
To mesh or not to mesh?

I have mesh in my pond baskets and as you said so yourself, it's to hold the soil in the basket. The first time I tried it, I though the substrate would compact enough to not escape but I was wrong. Slowly but surely I was losing soil.

The mesh, at least the one that I use, doesn't cover the holes completely though, they're just smaller and still accomplish the same thing.

 

[Clicio]

Holes in the colander are too big and let soil leak out?

Yes, that's what I said. The question was, with the mesh the same results will happen ?

 

[Clicio]

Let me rephrase it:

Why don't we just use MESH POTS instead of mesh pots with a colander around it?

 

[bonsaidave]

Just keeps the soil in. Smaller holes in baskets and colanders would be nice but we are using them for something other than the intended purpose.



Mesh keeps root pruned fine.

 

[Rodrigo]

Rigidity of the mesh for new root growth? What I mean is, if it's too flimsy it would shift the soil every time it was moved, no?

 

[Clicio]

Rigidity of the mesh for new root growth? What I mean is, if it's too flimsy it would shift the soil every time it was moved, no?

It depends on the mesh. IF we have rigid enough meshlike material...

 

[Rodrigo]

I mean I think if it's rigid enough it may work. Do you have a mesh in mind that you think would work or are you just wondering in general?

 

[LanceMac10]

Bro, bigger substrate...


Colanders sound like more watering work for me, let alone your climate. I feel their efficacy is somewhat overstated. But it's important to use what your comfortable with!

 

[Cadillactaste]

@Adair M told me recently...colanders are for pines.

 

[Vance Wood]

Bro, bigger substrate...
View attachment 184129

Colanders sound like more watering work for me, let alone your climate. I feel their efficacy is somewhat overstated. But it's important to use what your comfortable with!

If you have not tried it I don't understand how in all honesty you can pillory it. Don't you think it might be better to say I know such and such is true rather than say you feel it is somewhat overstated? The only way you would know this is by trying it.

 

[sparklemotion]

It depends on the mesh. IF we have rigid enough meshlike material...

Fabric pots operate on a similar principle. @bonsaidave posted a more rigid mesh option. @sorce started a thread on mesh/concrete pots.

If you're feeling crafty you could probably make something work with plastic canvas and zip ties/string/wire.

Or, you can go the easy way, and buy colanders/pond baskets and use floppy mesh to hold the soil in.

 

[wsteinhoff]

With the colanders from tigerchef.com I have had no need to line the inside with mesh. Very little soil comes out when I'm filling the colander and once it's been wetted nothing comes out. I only need to line the bottom with mesh on the large sized flat bottomed square colanders vs the round ones. This is using the small particle size of Napa DE.

 

[Vance Wood]

Here are represented the three major sizes I used to produce these planters in. I made this design in the 1980's and had it patented. I used the technique of screen sided and bottom planters for many years and durning that time I have had excellent results with the system. The soil does not leak out, they do not dry out particularly fast and do not require any special attention during periods of very hot weather any more than trees planted in regular pots. Growing one of these devices inside another will actually diminish the effectiveness of the devise as well as burying it in the ground.

 

[MrFancyPlants]

Here are represented the three major sizes I used to produce these planters in. I made this design in the 1980's and had it patented. I used the technique of screen sided and bottom planters for many years and durning that time I have had excellent results with the system. The soil does not leak out, they do not dry out particularly fast and do not require any special attention during periods of very hot weather any more than trees planted in regular pots. Growing one of these devices inside another will actually diminish the effectiveness of the devise as well as burying it in the ground.

View attachment 184135

And, they look darn good too. The one drawback, I heard, is that the wood rots out eventually. I wonder if you updated your design with some 3D printed UV stable materials (just for the frame) if your design could see production again. I don’t know enough to know if production costs would be too high.

 

[MrFancyPlants]

Also I never got the double colender thing. Although, I do let some of mine escape into the ground if Ineed some bulk.

 

[Clicio]

Here are represented the three major sizes I used to produce these planters in.

This is EXACTLY what I had in mind; thank you very much @Vance Wood !

 

[Clicio]

@Rodrigo , what I had in mind is the grow box @Vance Wood has patented.
It makes much more sense!
I guess lining a colander with mesh (if the mesh is the working principle as it seems) is to avoid the work of doing it directly with mesh; it's like the double ou triple colander method; instead of switching for a bigger colander after every X years, it's less work just to dump the smaller one inside the bigger.

 

[Vance Wood]

And, they look darn good too. The one drawback, I heard, is that the wood rots out eventually. I wonder if you updated your design with some 3D printed UV stable materials (just for the frame) if your design could see production again. I don’t know enough to know if production costs would be too high.

No because the patent has expired and the Chinese ripped off the patent years ago. That's where the pond baskets and Anderson flats came from. I am not posting this to get sympathy but to explain that in my experience I have been working with this kind of thing for many years longer than most everyone. Most of the arguments and variations I keep hearing discussed are vapid.