Guide for choosing the pot size and style for your tree

[IndorBonsai]

I have been putting this post off for awhile now. It is hard for me to word my posts so that they are easily understood.( this is why I edit my posts so often) LOL. So here I go

OK, trying to choose the right pot for your Bonsai Tree can be hard. This post is hopefully going to give a few pointers and some useful information that might make it easier for you.

First off the shape of the pot does make a big difference,
Take a rectangle sponge and get it wet, lay it flat over a screen notice how much water drains out.

[url=https://img355.imageshack.us/my.php?image=sponge1.jpg][img]https://img355.imageshack.us/img355/9426/sponge1.jpg[/img][/url]

This represents a shallow style pot used in bonsai, a wide, shallow pot. Kinda like a forest planting style pot.
This style pot, like the sponge, holds alot of water at first but drys out fairly fast.

Now turn the sponge on its side like this, This represents a wide deep pot. Notice that more water drains out of the sponge.

[url=https://img361.imageshack.us/my.php?image=sponge2.jpg][img]https://img361.imageshack.us/img361/9911/sponge2.jpg[/img][/url]

Using a pot that is shaped like this wont hold as much water in the soil, and it will dry out a little slower. This represents the most common style bonsai pot, like this 7 inch chinese pot.

[url=https://img355.imageshack.us/my.php?image=elm1b.jpg][img]https://img355.imageshack.us/img355/3157/elm1b.jpg[/img][/url]

Now turn the sponge so it is standing on its end, This represents a tall narrow pot, like a pot used for cascade style trees.

[url=https://img8.imageshack.us/my.php?image=sponge3.jpg][img]https://img8.imageshack.us/img8/9714/sponge3.jpg[/img][/url]

Notice that even more water drains out of the sponge, This style pot holds the least amount of water but also drys out the slowest.


Now your probably wondering ok how does this help me choose a pot?

Now that you know how the shape of the pot affects the amount of water your soil holds. You can adjust your soil mix properly for your trees water needs and the pot style it is in.

Here is a example I over potted this chinese elm, so it will grow bigger. Over potting is kinda tricky because the roots are not helping remove alot of excess water from the soil. This can cause stagnate/ rotting conditions for the roots.

[url=https://img361.imageshack.us/my.php?image=elm2a.jpg][img]https://img361.imageshack.us/img361/7937/elm2a.jpg[/img][/url]

Because the pot it is in holds a good amount of water and drys out at a slower rate, and the trees roots are not big enough to help remove moisture from the soil now. I used a course large particle soil that drains really good and fast. This should help keep the soil from holding to much water and help it dry out faster.

Over time the larger organic particles will decompose and become smaller. causing the soil to hold more water. But during that same amount of time the roots of the tree will be growing and using more water. Getting the soil mix correct is the challenge. Trying to balance it out so the water needs of the tree and the decomposition of the organic particles work together and the soil still drains freely for a few years. This is probably the hardest part of choosing a soil mix.

Or say you have a nice cascade style tropical tree that likes alot of water.
Now that you know that a cascade style pot dosent hold as much water, you can adjust your soil mix to help the soil hold more water.

Anyways I thought this might be useful, I will probably have to do some editing later but I think you get what I am trying to say LOL

If anyone has more information about choosing a pot and style, or just any comments about this post, let me know.

P.S. here is a link to my other guides for bonsai.

A guide for making Bonsai soil- link
https://www.helpfulgardener.com/forum/viewtopic.php?t=15040

A guide for Re-potting a Bonsai- link
https://www.helpfulgardener.com/forum/viewtopic.php?t=14972

[bonsaiboy]

I am not quite sure how correct this information is. Although dimensions do play a role in how fast the soil dries, it might be worth mentioning the size of the pot and its material also have an effect on how fast the soil dries. For example, a glazed pot dries slower than an unglazed one, and a shohin pot will dry slower than a mame pot. Theoretically, assuming the pot is able to "breathe" (as any clay pot does) the soils dry time should be based more along how large the surface area is compared to the volume (larger volume=smaller surface area compared to the volume, and thus a slower dry time), and not nesissarily the shape. In simpler terms, the closer the pot is to being a cube, the slower the dry time. However, one must also take into account that the pots top has the fastest water evaporation level, and therefore the flatter the pot, the faster water evaporates from the soil contents. This means that cascade pots tend to hold the most water, not the other way around.

Sorry if that is confusing, but here is what I stated in a nutshell: so many factors go into determining a pots dry time that it is not practical to say any one pot will dry faster or hold more water than another based on shape alone.

[IndorBonsai]

When doing my experiments, I was using only this Volcanic Pumice as a soil medium ( no tree ). I was measuring the water before and after I poured it through this soil medium.

[url=https://img29.imageshack.us/my.php?image=soil2.jpg][img]https://img29.imageshack.us/img29/4015/soil2.jpg[/img][/url]

I kept getting the same results as posted above. The deeper and narrower pots( cascade style) hold less water. They still hold some moisture ( which does evaporate alot slower than a wide shallow pot ) But they hold less water.

Wider pots, I think because of the surface area across the bottom of the pot, seem to hold more water. ( which evaporates quicker like you said )

I could be wrong, but with my experimenting these are the results I keep getting.
Someone else should do some experimenting with this to see if they get the same results as I have.

[Gnome]

Jason,

The shape of the pot does indeed have some bearing upon how quickly it drains. If the volume of two pots are same but one is shallow an the other is tall, the taller one drains more readily. This is due to the effects of gravity. This is one reason why bonsai growers, who generally use rather shallow pots, insist upon a free draining medium.

You can demonstrate this with your sponge. Saturate the sponge and allow it to drain briefly in a horizontal position. Now change the orientation to a vertical one and note how much more water drains out. As bonsaiboy notes, there are many other things to consider but shape does play a role.

Norm

[logic1248]

This doesn't concern drainage but the shape and color of a pot can really change the overall aura of the tree. I do not think this should override function at any time but once the training of the tree has slowed down I start looking at it as a piece of art and color and form are important in any piece of art. I also have always read that (obviously with exceptions) the pot should be as deep as the trunk is thick and the photos I see of trees potted this way and do for the most part pop a little more. Also the color can symbolize the native habitat of the tree traditionally , red for mountains, blue for wetlands and shorelines, green for prairies and meadows etc.The shape can do the same thing if chosen carefully but there is way more than one right answer although perfect circles and squares are harder to perfect in my opinion. These tips are used to enhance the harmony training and exaggerate the age they are not there to tie your tree to one pot, if think it is more beautiful in another less traditional choice , then that is what it should be potted in, the tree is there to make people smile, especially you!

ps if you are having problems with thin pots drying out too fast, first water it with the submersion method and add a litte extra spag. moss to the soil, I also added a couple spoons of vermiculite to soil for a really thin pot for a ficus and it seemed to work wonders together. Thanks for you time.

[IndorBonsai]

Nice ! I knew that evergreen type trees should be placed in non glazed pots, But I dident know that the color of a glazed pot meant so many different things. Blue is my favorite color so I usually buy blue pots.

This is good information thanks

[logic1248]

This is just my opinion but the tree in the picture above would look great in a red, straight sided, rectangle pot, potted slightly right and back of center, also it looks like a pretty interesting candidate for root over rock, ever think about that?