Why do bonsai pots have large drainage holes ?

[M. Frary]

Flattery will get you nowhere.

 

[Anthony]

Actually Vinny,

Gogerah [ Mike ] is a very decent guy, otherwise I would never invited him down for a rest from eating
all that meat, to try some coconut, roti and dal / doubles ect.

I mentioned your posts to Khaimraj , my brother - in - law, he wondered if you didn't have the problem
some folk who get into Art get. A fear of producing a product, so they spend endless time on mediums
or pigments or other.

Hope you stick around to show what you can do.

As to hole-y pots, well we did two earthenware pots with holes matching the ratio and size of the air-pot
but didn't get the same results. Guess the stick-outs on the black plastic help a great deal with the air
pruning.

If I didn't mention, a glazed porous pot also helps with soils that need to be more dryish.
Seen with the Chinese serissa. we lost an old one a while back because we didn't know they didn't like
over moist soil.
So now they are in porous but glazed Chinese pots.
Good Day
Anthony

* I thought I might share with you. Tamarind in red pot grown as a normal germinated see.
Styro container - idea borrowed from J.B.pine technique ----------- cut 2.5 cm [ can be less ] from cotyledons and replanted.
can give branches, if need from as low as 2.5 cm to the soil.

On our side, tamarinds have no surface roots, as they age they build mightily off the bole / trunk.

 

[M. Frary]

ry some coconut, roti and dal / doubles ect.

I went to the doctors today and after seeing the number on the scale I'm starting to eat better as of today.
Thank you Anthony.

 

[MichaelS]

"Bonsai Hunter, post: 405771, member: 19402"]So if I wanted to buy a tree from a nursery to develop as a bonsai, are you saying I should buy the one growing in a regular plastic pot instead of an air pruning pot

No. You should buy you favourite tree.
I read a paper on a trial of different containers including smooth sided and air pots. (promotional U tube videos are not the place to get unbiased reports) They found no difference in calliper size. But you need to weigh up the facts and then decide whether you want to go to the trouble of using these pots. Because (with air pruning) you get a more even root distribution throughout the root ball, you get more roots and hence there is a tendency for more even root thickness but we want thicker roots at the nebari and these pots will not help with that. We need to regularly trim the roots beneath the trunk regardless of what we use. There's no need to be concerned with spiralling or deformed roots because they will be cut off before they adversely affect tree health. Air pots produced more kinks than smooth sided pots, whereas smooth sided pots produced more circling roots. All this stuff needs to be cut off.
The diameter of the five largest roots was greater in the smooth sided pots than the Air pots.
Now, tell me again the reason for using air pruning for bonsai. If there is some advantage which I have missed I would be happy to use them.

 

[Vance Wood]

First I am not new to air pruning. I use containers very much like colanders as training pots. They work fine but I also use pots with solid sides and they also work fine. I have not seen one difference or advantage of on over the other whatsoever.

We are talking about 2 different things.

An Anderson flat is used as training pot and it has solid sides and a mesh bottom, I would not consider it the same as a colander or similar that has holes on the side.

The the pot you posted in the first picture and the title of the thread asks about BONSAI pots which is different from a training pot.



Scott is absolutely correct. You can put as many holes in the pot that you want, if the soil does not drain it doesnt matter one iota.

Here is a scots pine that I have had for 5 years. This picture was taken in 2012.

View attachment 123842

See the pot it is in? Exactly what you are talking about right?
However there is window screen lining the inside of the pot and the soil is a mixture of sand and gravel.
The bottom of the pot has several 3/8 inch holes for drainage. Being sand, the soil always drained pretty fast when I watered.

The tree was repotted from its nursery container to that pot in the spring of 2012.
The tree did ok. It grew some but wasnt extremely vigorous.

Fast forward to March 2016.
I repotted the tree into a shallow, plastic bonsai shaped training pot with a mixture of sifted lava, pumice, akadama, gravel and charcoal.
When I took it out of the sand and gravel, I noted that in 4 years there had been very little root growth. There was some but certainly not what I would expect after 4 years.

View attachment 123843

I put moss over the soil to help it retain a bit more moisture. I find the mix to dry out very quickly when it is new. I removed the moss in September.
Note: This training pot has a lot less holes than the old training pot.

Here is what I noticed when I removed the moss.
The tree went absolutely nuts with root growth. There were new roots everywhere.
The tree's branches had bulked up on wood to the point where one branch almost doubled in thickness.

So the tree went from a pot with more holes and a sand mix to a pot with less holes and a larger sized (about 1/4" inch) soil mix.

I have no doubt that the response I got from the tree has everything to do with the change in soil, not the change in the pot.
Ive seen similar results just by changing the soil and keeping the same pot as in the first picture.

You must have done something wrong or you did not recognize what you were looking at. With planters like this the tree produces mostly fine feeder roots, not the fibrous spaghetti like circling roots you see normally with a pine in a normal nursery container.

 

[Paradox]

You must have done something wrong or you did not recognize what you were looking at. With planters like this the tree produces mostly fine feeder roots, not the fibrous spaghetti like circling roots you see normally with a pine in a normal nursery container.

Nope, I know I havent been doing this as long as you have but I have been doing this long enough and have repotted enough trees to know exactly what I saw.
The tree in the sand mix in the "holey pot" had little to no root growth. There was some new root growth but not much, particularly for a tree that had been in that pot for 4 years.
The only thing that was wrong was the sand. It was pretty dense but still drained but not as fast as a larger mix.
After I repotted into a larger, sifted soil mix, the tree sent out tons of fine feeder roots, not "spaghetti" roots and the tree put significant wood on several branches.

 

[thomas22]

"Some men, you just can't reach....."

"So you get what we had here last week"

 

[MichaelS]

"Anthony, post: 405816, member: 14228"]

If I didn't mention, a glazed porous pot also helps with soils that need to be more dryish.

Yes. I lost quite a few Japanese white pines in plastic but what I have left are much happier in terra cotta. It also helps keep these alpine plants' roots cool through evaporation in our hot summer. Air pots might work well for these too?

 

[Anthony]

Why the drainage holes and the mesh -

[1] The mesh is to keep the soil in, allow the water out. To keep insects / worms out.

[2] The soil will function as - coarse loam, but not just soil. As bonsai soil mixes.

However the mixes using 8 to 5 to 3 mm of inorganic will not need to have the tree bare rooted [ as opposed to repotted ]
as the process of decay by aged compost does not include fines of organic material.
Fines come from the beginning of decay [ e.g bark chips ] after compost, the glue compounds take over.

[3] If you want many holes in a fired Bonsai pot, just use some clay, make a well, and an appropriate drill bit.

Most of this is known, but as usual not many like to read, they want it in point form.
Good Day
Anthony

 

[jeanluc83]

Allow me to expose your hypocrisy :

If the wire holes are increased in number to match the drainage area of the bigger hole, wouldn't the drainage remain same as before ? Then mesh screens can be completely avoided.

But couldn't the small holes clog?

Here is a simple solution for the clogging issue pointed out earlier. Put a porous fabric on the entire floor.

Kind of like a mesh screen?

 

[Dav4]

[QUOTE



Kind of like a mesh screen?[/QUOTE]
But worse. Regardless of soil type, I've always found very fine material, perhaps organic debris from material that gets worked into the soil or soil aggregate remnants- what ever- on the bottom of the pot at re-pot time. I'm sure much of it is washed away through the large drainage holes covered in mesh. That fine silt will clog that fabric in short order and then you can kiss your great drainage goodbye....not that it would be that great covered with porous fabric in the first place?? None of this makes any sense....

 

[M. Frary]

I think @M. Frary is confusing the science part of bonsai with the art part. "Son, first show me your art portfolio before you question the design of the pencil" or "Hey you potters on this forum, please show your trees at once to officer M.Frary

I'm not confused one bit. Showing trees you have grown out in one of your fancy pots would be good enough.
I mean jeez,you come here touting your way is better than tried and true practices.
Show us some results rather than just surmise.
I use colanders to get fine roots on collected material. Also on pines. That is to get fibrous roots for the bonsai pot. But I don't grow out trees in them. They do great and grow like gangbusters the first year but as the colander fills with fibrous roots they slow down.
I actually have put elm seeds in colanders and in buckets. The ones in buckets are twice as large as the ones I started in colanders.
Oh yeah. When I get home Saturday I'll take some pictures to prove it.
Can you do the same?