The Bonsai Soil Argument

[Attmos]

Probably a good thing!

Hey! lol

 

[JudyB]

Apologies, and you're right, I probably shouldn't have started this post.
I also forgot to make the distinction between developing trees/pre-bonsai... and fully developed bonsai.

Yes, and Yes.... once you have something that means a lot to you, you will not choose based on cost.

 

[Bonsella]

Potting soil is so bad that trees only grow in it until you decide to buy it from the nursery, it doesn't matter if it's a year's seedling or a 10yo 5feet tall plant, they should be all dead.

But you buy it to save it

 

[Attmos]

Yes, and Yes.... once you have something that means a lot to you, you will not choose based on cost.

That's probly the only real way to look at it.
I'd like to invest more, but my little trees (that will most likely take decades to develop) don't really warrant a lot of expense at the moment, in my opinion.

I need to buy a pre-bonsai. Something I'm gonna want to devote time and money to its development. Lot of people have mentioned this to me, lol. Anyway, yeah..

 

[Glaucus]

Potting soil is so bad that trees only grow in it until you decide to buy it from the nursery, it doesn't matter if it's a year's seedling or a 10yo 5feet tall plant, they should be all dead.

But you buy it to save it

That's just not true. Trees in containers are produced at a nursery and then shipped to a wholesaler. There they either get sold or discarded. A shop isn't a nursery so they don't take trees that don't sell and put them in larger pots with new potting soil.
They do not ship them back to the nursery when they aren't sold. They get written off.
Nurseries carefully time when to sell their plants. Plants that are at a wholesaler are at the end of the road for that specific pot that they are in. If there was 1 year more of root space in that pot, the nursery would keep it for 1 more year. Or they would have put it in a smaller pot.

How do you think a nursery produces a 10 year old tree? You think they have extremely cheap soil that lasts just 1 year, then kills the plant when not sold? And then premium 10+ year soil where the tree can grow to become a 5 feet tall tree in 10 years, and then be sold, or die.

Please try to understand why potting soil is good for plants but bad for trees in bonsai pots.

 

[Bonsella]

That's just not true. Trees in containers are produced at a nursery and then shipped to a wholesaler. There they either get sold or discarded. A shop isn't a nursery so they don't take trees that don't sell and put them in larger pots with new potting soil.
They do not ship them back to the nursery when they aren't sold. They get written off.
Nurseries carefully time when to sell their plants. Plants that are at a wholesaler are at the end of the road for that specific pot that they are in. If there was 1 year more of root space in that pot, the nursery would keep it for 1 more year. Or they would have put it in a smaller pot.

How do you think a nursery produces a 10 year old tree? You think they have extremely cheap soil that lasts just 1 year, then kills the plant when not sold? And then premium 10+ year soil where the tree can grow to become a 5 feet tall tree in 10 years, and then be sold, or die.

Please try to understand why potting soil is good for plants but bad for trees in bonsai pots.

When the tree doesn't fit, they move it to a larger pot with the same or worse potting soil. Until they sell it.
You do the same with akadama, but you prune the roots to fit it in the same pot you had.

 

[Glaucus]

Yes and no. And no, uppotting a nursery plant in a container with mostly organic potting mix, is not the same as repotting say a pine bonsai in mostly akadama.

Saying nursery container plants in potting mix have a death sentence on them because of the soil/peat/potting mix, is just a weird take.

 

[Bonsella]

And that's why I don't take this discussions any further.
I won't convince you and you won't convince me

 

[Glaucus]

Then why reply? Don't accuse me of being intellectually lazy or uncurious.
Please don't make a cheeky comment like that. If I am truly incorrect, you need to make arguments. Or you are just wasting everyone's time.

Obviously plants in containers need to be taken care of. Not doing so would be lead to eventual death aka 'a death sentence' in most climates, yes.
But soil/peat/bark/organic mixes are great and in most cases is the absolutely ideal stuff to use for containerized plants.
Not a cheap shortcut that compromises quality and not a death sentence either.

That the nursery industry uses field growing to produce trees of a certain size/age is because in terms of resources, labour costs, weight, etc, at some point there is a crossover and the container with potting soil is no longer ideal.
Peat moss is more expensive in say Oregon than pumice. But the nurseries grow their plants in peat moss or (composted) bark. Despite the winter rainy season.
If 100% pumice or perlite or volcanic clay gave better results for half the cost, people would use it.
The cost of peat moss will make nurseries try to move away from it. And more aeration is good. So there is room for improvement. But peat is the gold standard for many many plants.

 

[AGentleman]

Thanks for starting this thread @Attmos
I've read bits and bobs about soil on this site but it's great to have something current.
I'm just starting out and have pre-bonsai trees in a wide range of soils from amended potting mix, to fine particle size pumice and lava, to washed and sieved quality pumice-lava-pine bark.
I'm really having trouble learning how to water properly and clearly the substrate has a massive impact on that.

I'm ready to put up some trees grown in 70% pine bark potting soil.

But I really came here to ask @Shibui what is the other 30% in your mix and if you would post a tree grown in it?
Thanks,
Greg

 

[Leo in N E Illinois]

@Attmos and others new to the hobby. There are no stupid questions. Asking soil questions is important, and the answer that "only akadama will do" is not good enough. You need to understand the interplay between your soil components, your irrigation water chemistry, water frequency, and your fertilizer. This is a complex interaction, not easy to fully grasp in a few short posts.

I started learning about bonsai when I was only 15, in 1970, at that time in USA the few books available recommended crushed granite and garden soil as potting mix. It was not until the middle or late 1980's that better translations of Japanese bonsai books, and Japanese trained teachers like Bill Valavanis began explaining the horticulture related to bonsai, I forget when Akadama became available in the mid-west. I know it was available first on the west coast, then followed by east coast and thru Valavanis' nursery. Now I can pick it up at Hidden Gardens in Willowbrook IL, a mere hour drive from my home.

The Hidden Gardens in Willowbrook, IL

I also was deep into orchid horticulture through my many years of learning bonsai. One thing I can tell you, you can grow an orchid or a tree in just about any media if you really understand how to water the mix correctly. I've grown a few orchids in rubber tire chips, just to prove this point. I switched back to my "regular" fir bark based orchid mix, But the point was made. An ash tree and a black locust seedling sprouted in different pots of my rubber tire orchids, and they grew well.

Skipping 40 years to present,

Now imported Akadama and Kanuma are widely available, and a blend of pumice and or lava (scoria) is one of the most often recommended mixes. Others still commonly used components are fir bark, perlite, diatomaceous earth if you can find the right particle size. Somewhat out of fashion, but actually okay if in quantities less than 25% of the total mix, Turface and other calcined clay products. There are problems with calcined clay products, see the many threads on specific brand names. But generally if the percentage of calcined clay is less than 25% of the total volume of the mix, most don't have problems.

Perlite is heated and expanded obsidian, at least 75% silicon dioxide, essentially volcanic glass. Perlite is very light weight, which in bonsai pots can be a problem, Without another component perlite will allow the tree to shift around too much. But in its favor, perlite is widely available in different particle sizes and cheap enough. Dry perlite will float on water. A covering of moss over the media will help hold the perlite in place.

Pumice is another mined volcanic product, Here the silica dioxide content can vary more, from as high as 75% down to less than 50%. Pumice can chemically be from Rhyolite (high silica) through Dacite (intermediate silica) through basalt (relatively low silica dioxide, around 50%) Pumice is defined mainly by its bubble (vesicle) size and thickness of the walls between the vesicles. Pumice may or may not float on water. Most I've purchased usually sinks.

Lava (scoria) is same chemically as Pumice but with fewer, more coarse vesicles and and a greater density. There is a wide range of color for lava depending on source, from gray to red to black.

East of the Mississippi, most of the perlite and pumice comes from quarries in New Mexico, from ignimbrite deposits from El Valle caldera and other New Mexico volcanoes.

Pumice can be used as 100% for junipers, and mixed down to any % desired for other species. I have had junipers go 10 years in pumice without the pumice deteriorating. I tend to use liquid fertilizers, so there is little "clogging up" of the mix from debris of solid fertilizer. If you use rapeseed cake or other pellet or cake fertilizers, you might have to repot more often than once every 10 years.

 

[Orion_metalhead]

Ive had mixed results with organics in my mixes in pots. I do still use a small amount of sifted bark as a water retention ingredient.

For growing out, cuttings, seedlings, and boxes (i add pea gravel for large boxes) 50% compost and 50% perlite has worked well for me.

But once in a proper bonsai pot, pumice, perlite and pine bark has done well. ive used saf-t-sorb calcined clay as a filler but im phasing out. I may reintegrate 8822.

 

[Shibui]

But I really came here to ask @Shibui what is the other 30% in your mix and if you would post a tree grown in it?

70% 3-6mm pine bark, 30% coarse sand (propagating sand) with some zeolite. Dolomite, Iron sulphate, Granusol long term iron, micronutrient mix and controlled release fertiliser added in smaller quantities.

Some of my trees:
Took some photos of the smaller bonsai this morning. Just coming into leaf. These trees anywhere from 4-10 years old. All grown in the above mix.
Trident maples:

Cotoneaster:

Chinese elms:

Ficus:

Buxus harlandii

Some bigger trees (photos from last year)
Azalea: Collected tree. Has been in the pot for 15 years

Japanese maple: Grown from seed - around 30 years

Japanese black pine: From seed, around 15 years

 

[BaKiBonsai]

And just to make sure I wasn't being gas-lit, I went down and took a cup of my Hyuga pumice (which is lighter than my west coast/oregon pumice), dumped it into a 5 gallon bucket that had 6" of water in it, and watched it go straight to the bottom like lead.

I just repotted a houseplant in pumice. Gave it a good soak in order to was and hydrate it. Some really did float, to my surprise.

 

[BaKiBonsai]

I think about this a lot. I used to follow a lot of chinese youtubers from penjing nurseries and they used clay soil from the ground, VERY lightly ammended sometimes with small sized gravel collected from streams.

I have seen noticed similar soil. I have always wondered why it seems to work, it looks so dense. I would love to have some of the soil they have to see how it holds up.

 

[AGentleman]

Thanks @Shibui
They're impressive trees! I especially like the Japanese Maple.
Greg

 

[Bonsai Nut]

Some really did float, to my surprise.

Yes... I have to be careful that I always say things like "no pumice I have ever used" or "I just checked my Hyuga pumice". I don't doubt there are tons of pumice types/brands available, and if people say that their pumice floats, I have to assume they are using a different type. Same thing with akadama, where some people get really frustrated because they buy a certain brand and it breaks down after one year, while other brands will remain in hard piece form for several seasons and only break down very slowly.

 

[Bonsella]

Then why reply? Don't accuse me of being intellectually lazy or uncurious.
Please don't make a cheeky comment like that. If I am truly incorrect, you need to make arguments. Or you are just wasting everyone's time.

Obviously plants in containers need to be taken care of. Not doing so would be lead to eventual death aka 'a death sentence' in most climates, yes.
But soil/peat/bark/organic mixes are great and in most cases is the absolutely ideal stuff to use for containerized plants.
Not a cheap shortcut that compromises quality and not a death sentence either.

That the nursery industry uses field growing to produce trees of a certain size/age is because in terms of resources, labour costs, weight, etc, at some point there is a crossover and the container with potting soil is no longer ideal.
Peat moss is more expensive in say Oregon than pumice. But the nurseries grow their plants in peat moss or (composted) bark. Despite the winter rainy season.
If 100% pumice or perlite or volcanic clay gave better results for half the cost, people would use it.
The cost of peat moss will make nurseries try to move away from it. And more aeration is good. So there is room for improvement. But peat is the gold standard for many many plants.

I just let my opinion.
If you don't like my opinion i won't lose my time trying to convince you because you don't want to be convinced, you just want to prove your terms.
Simple. Bye.

 

[Nera]

@Shibui I like your soil ingredients, great mix!

 

[Glaucus]

I just let my opinion.
If you don't like my opinion i won't lose my time trying to convince you because you don't want to be convinced, you just want to prove your terms.
Simple. Bye.

Literally no one on the planet ever will be convinced on anything by a post like this. No one asked you to post your opinion.