What size nursery pot to use? Rule of thumb?

[geargarcon]

The only thing good for nursery pots is stuff you are growing out to later layer new roots on.

One of the largest F-U's in bonsai is correcting roots that were grown in nursery pots.

One of the most important rules, one of the only that should always be followed, is "Roots First". It's important because this is the beginning of your design and the beginning of your horticultural endeavor. It is the foundation on which everything is built.

Imagine if when we built a house, we poured like 3/4 of the foundation. Then before the walls go up, we remove some of the foundation just to replace it. Then before the electrician comes in, we tear out more of the foundation and repour it. Then before the plumber comes in, same. By the time the painter came, the house would be wobbly.

The problem with nursery pots, is the design promotes roots that grow in positions where feeder roots almost always get near fully removed when trying to fit it into a bonsai pot.

Using airpruning baskets for early training makes for excellent control of visible surface root growth and a matte of feeder roots that almost can't run and ruin design. This matte of feeders is the foundation on which everything else should be grown, because it can be repotted with the least disturbance to it's usefulness.

...

There is more to "drainage layers" than water.

.

Sorce

very interesting. I’ve heard of air pruning pots before but haven’t really looked into them. Definitely intriguing.

I wonder if I could get a similar effect by drilling a copious amount of holes in a pot I currently have.

 

[cornfed]

@geargarcon check it out:

Google Dr. Carl Whitcomb for more info.

I buy all mine here: https://myrootmaker.com/

 

[sorce]

I wonder if I could get a similar effect by drilling a copious amount of holes in a pot I currently have.

I'm a stickler for what is a bonsai approved root pruning container.

Considering all time, cost, sizability and foreverness, I haven't found anything better.

Those Pot Materials!

Tired of going downstairs to pick up trees that test gravity in the wind, and understanding the benefits of colanders, I decided to solve a couple problems. Crappy pots, and crappy broken pots! One 4in clay completely destroyed, in a sock holding it together. Ham containers, small nursery...

www.bonsainut.com

We need to stop looking at Bonsai as part "nursery horticulture" and part design and start viewing it as the one single entirety it is. Both, always.

It is as simple as "all nursery trees are intended to be transferred to the ground". Once this is considered, most nursery trade information is useless to us.

Sorce

 

[Leo in N E Illinois]

Drainage layer doesn't do anything for drainage because water doesn't like to move between the different mediums. Just use one kind of soil all the way down.

Gallon could be good to start but I would expect a ficus or elm to fill them up within a season outdoors. Maybe an Anderson flat after that?

Drainage layer comment is true, the "need for a drainage layer" is one of the bigger bogus myths perpetuated in bonsai literature.

So is a "coarse drainage layer" at the bottom, actually worse than just having the same soil type all the way down? I have been doing a drainage layer of rock just because I ran out of mesh and all my pots have holes too large for any type of bonsai soil.

Take the time to get some mesh to cover your drainage holes. The plastic mesh backing available at craft shops for making hooked rugs and wall hangings is available at every Michael's and other craft shops (Hobby Lobby, etc) there is probably one of these types of stores in a nearby town. Window screen will even work in a pinch. I've used a layer of 1/4 inch hardware cloth with a layer of window screen on top. Using rocks and creating drainage layers is a hold over from 19th century British gardening books, written before window screen and other mesh products were inexpensive. Creating layers of different particle size in a pot will inhibit the movement of water from one layer to the other. It can create real problems. Fortunately, usually pretty quickly the layers that one takes time to create, get mixed the first time the pot is flooded with water, especially if any of the particles have enough air voids that they will float. This mixing then reduces the amount of air voids in the potting media. The more uniform the particle size for a potting mix, the better the air penetration and water movement will be easier. A box full of marbles will hold more air than a box full of bowling balls, marbles and sand. A mix with large differences in particle sizes can become very dense, with little air penetration and be difficult to get water to penetrate.

On the original topic of training pot size.

Nearly all bonsai pots for trees less than 1.5 meters tall (trees under roughly 4 feet tall) the bonsai pots are less than 4 inches or 10 centimeters in depth. You will not find "off the shelf" bonsai pots much deeper than 4 inches, except for pots intended for cascade style trees. Cascade pots can be very deep, I have one that is 5 inches in diameter and 2 feet in height. I don't have a serious enough cascade for that one, ....yet.

Given the shallow nature of bonsai pots for upright and slanting styles, training pots will serve you better if they are equally shallow. I do not use pots deeper than 5 inches for this reason. An Anderson flat that is 16 x 16 x 5 inches deep with a mesh bottom is my favorite training pot. It holds roughly 3 gallons, or 12 liters of potting media. You can fill it all the way up or you can use it only partially filled.

What is the right size pot to use? Generally you want room for roots to add an entire season's worth of growth in the horizontal dimensions. You also want the pot to go from wet to barely moist within a week or two.

There are no hard and fast "rules", the training pot should be at least 2 inches larger in diameter than the roots. If the pot is drying out quicker than your normal ability to get out there and water it, then the pot is too small. If the media is staying moist for more than 2 weeks, the pot is too large. That's pretty much it.

 

[geargarcon]

Well all I wanted to know was if I should get the 6” tall pots or the 5” tall pots - no you guys have me questioning everything!!!! I don’t even know who I am anymore!

 

[ShadyStump]

Well all I wanted to know was if I should get the 6” tall pots or the 5” tall pots - no you guys have me questioning everything!!!! I don’t even know who I am anymore!

Welcome to bonsai, my friend! LOL

If they're the same volume, get the wider, shorter ones. If the wider ones are greater volume, get those. Wide and shallow is where most of your trees will wind up, so get as close to that as you dare from the get go, without trimming roots right off the bat.

 

[cornfed]

You all kind of inspired me to go back to Bonsai Heresy. Pg 61 he talks about this subject.

To summarize, he said that doubling the pot size increases biomass production by 43%.

BUT the real trick is to gradually up-pot, because if you put a small root system in a large pot it generally has all the water and nutrients it needs, so the roots are not growing quickly to search out more water. Also if the container holds more water than the roots can suck up it will reduce air-flow in the substrate which slows metabolism.

Pg. 61. Good stuff. (Note, specifically for trees where you want to thicken the trunk, not even pre-bonsai).

I wish I bought this book before I potted all my trees this spring. I made some mistakes...

 

[geargarcon]

You all kind of inspired me to go back to Bonsai Heresy. Pg 61 he talks about this subject.

To summarize, he said that doubling the pot size increases biomass production by 43%.

BUT the real trick is to gradually up-pot, because if you put a small root system in a large pot it generally has all the water and nutrients it needs, so the roots are not growing quickly to search out more water. Also if the container holds more water than the roots can suck up it will reduce air-flow in the substrate which slows metabolism.

Pg. 61. Good stuff. (Note, specifically for trees where you want to thicken the trunk, not even pre-bonsai).

I wish I bought this book before I potted all my trees this spring. I made some mistakes...

I have that on my short list of books. Is there anywhere you can get it as an ebook? Or maybe get a used copy?

 

[cornfed]

I think stonelantern is the only place. If you have a local bonsai society you may be able to borrow it from one of the members.

 

[Enfield Snapper]

I have that on my short list of books. Is there anywhere you can get it as an ebook? Or maybe get a used copy?

It's not available as an ebook. The publishing costs were funded by Stone Lantern, and neither their site nor Hagedorn's mention any other formats, so paperback is the only way to get it.

It might seem expensive, but it's worth the cost.

 

[Leo in N E Illinois]

I bought a copy when it first came out, I did not feel it was expensive, there is more "good information" and "pure gold information" in that book than any 5 books with glossy photos and significantly higher prices combined.

It has been a long time since I learned more than one or two new things from a book, "Bonsai Heresy" had me taking notes in every chapter. This book would be a bargain at twice the price.

 

[LanceMac10]

To paraphrase the great @GrimLore ....trees don't read books.

Get out and work your trees and observe the reaction. And this will take some years, not half a growing season.


Bonsai Heresy? Doesn't it mention in the forward that the info within is more geared towards trees in a refinement stage as opposed to raw material?

 

[Katie0317]

The only thing good for nursery pots is stuff you are growing out to later layer new roots on.

One of the largest F-U's in bonsai is correcting roots that were grown in nursery pots.

One of the most important rules, one of the only that should always be followed, is "Roots First". It's important because this is the beginning of your design and the beginning of your horticultural endeavor. It is the foundation on which everything is built.

Imagine if when we built a house, we poured like 3/4 of the foundation. Then before the walls go up, we remove some of the foundation just to replace it. Then before the electrician comes in, we tear out more of the foundation and repour it. Then before the plumber comes in, same. By the time the painter came, the house would be wobbly.

The problem with nursery pots, is the design promotes roots that grow in positions where feeder roots almost always get near fully removed when trying to fit it into a bonsai pot.

Using airpruning baskets for early training makes for excellent control of visible surface root growth and a matte of feeder roots that almost can't run and ruin design. This matte of feeders is the foundation on which everything else should be grown, because it can be repotted with the least disturbance to it's usefulness.

...

There is more to "drainage layers" than water.

.

Sorce

This is an interesting thread. Sorce, do you mind my asking for the name of your website if you have one so I can see your work? Thank you, Katie

 

[Carol 83]

This is an interesting thread. Sorce, do you mind my asking for the name of your website if you have one so I can see your work? Thank you, Katie

Look at the bottom of any of his posts, link to his website.

 

[Carol 83]

To paraphrase the great @GrimLore ....trees don't read books.

Damn, I miss him.

 

[geargarcon]

To paraphrase the great @GrimLore ....trees don't read books.

Get out and work your trees and observe the reaction. And this will take some years, not half a growing season.


Bonsai Heresy? Doesn't it mention in the forward that the info within is more geared towards trees in a refinement stage as opposed to raw material?

Hmmm… while I appreciate you sharing that sentiment, I’m going to stick with these guys…

If I have seen further, it is by standing upon the shoulders of giants
- Isaac Newton

Intelligent people learn from everything and everyone, average people from their experiences, foolish people already have all the answers.
- Socrates

The more that you read, the more things you will know. The more that you learn, the more places you'll go.
- Dr. Seuss

 

[Katie0317]

Look at the bottom of any of his posts, link to his website.

Thanks Carol, I hadn't noticed that.

 

[leatherback]

Look at the bottom of any of his posts, link to his website.

That is about pots, rather than bonsai though, innit?

 

[sorce]

This is an interesting thread. Sorce, do you mind my asking for the name of your website if you have one so I can see your work? Thank you, Katie

It is true my website there in the siggy line is only pots.
Search here for me saying "resorce". That's all my special bonsai info.

Sorce

 

[geargarcon]

Well after all of the feedback and suggestions and talk of root pruning and drainage layers and custom pots I’ve been rethinking my plan and scouring the internet… I think I’ve found my final solution.

- wider than it is tall unlike nursery pots
- air root pruning to encourage healthy root development
- lots of holes so good for drainage
- no holes big enough to lose soil, so no need for mesh or drainage layer

MESHPOT succulent pots