名媛直播

So, I started out with a simple enough question - what is akadama.

The first site explained it was a volcanic clay, heated. A few more sites stated the same. All reputable sites, so I thought I had the answer.

Then I started reading that akadama is in fact just a form of pumice. With people actively correcting others who referred to it as clay or soil. Now, slightly confused.

I was like, okay, akadama is just another kind of pumice - and pumice is a type of volcanic rock.

Then I started reading the debates about how akadama is better than pumice, you should mix pumice and Akadama, and the two are completely different.

My question is this... does anyone out there actually know what akadama is.

50% say it’s just a form of pumice (if this is so, why do people pair the two off like they are polar opposites)
50% say it’s volcanic clay.

My only assumption is that it’s both... that is, it’s Pumice that has broken down into a sedimentary form of clay. Just an assumption.

But based on all the knowledge out there. No one knows.

End of rant.

Akadama (赤玉土, akadamatsuchi, red ball earth) is a naturally occurring, granular clay-like mineral used as soil for bonsai trees and other container-grown plants. It is surface-mined, immediately sifted and bagged, and supplied in various grades: the deeper-mined grade being somewhat harder and more useful in horticulture than the more shallow-mined grades. Akadama may also act as one component of growing medium when combined with other elements such as sand, composted bark, peat, or crushed lava. Akadama's colour darkens when moist which can help the grower determine when to water a tree.[1]

While akadama is more costly than alternative soil components, it is prized by many growers for its ability to retain water and nutrients while still providing porosity and free drainage. For all of its qualities, many bonsai growers consider the cost of akadama prohibitive or unnecessary. Still other growers claim that when subjected to cold and wet climates, the granules progressively break down into smaller particles which inhibit drainage, an unwanted characteristic of bonsai soil. This problem can be avoided either by incorporating sand or grit in the soil mix, or by using the deeper-mined, harder grades.

Medium particle size is 2-6.5 mm and fine particle size is 1-2 mm.

Due to volcanic activity, Japan enjoys rich volcanic resources. After volcanic eruptions, volcanic rocks and pumice accumulate near the volcano. Using these unique resources, Japan has developed rich horticultural products. Akadama and kanuma soils are two representations.
According to the different kinds of cultivated plants, Akadama can not only be used alone, but also be mixed with other collocation substrates, such as pumice, stone, peat etc. Medium particle size is suitable for all kinds of potted plants, especially for cactus and succulent plants.

Components include silicon dioxide SiO2 42.7%, calcium oxide CaO 0.98%, magnesium oxide MgO 2.5%, manganese oxide MnO 0.15%, iron oxide Fe2O3 8.4% and aluminium oxide Al2O3 25.1%.

A pH of 6.9 and conductivity of 0.052 ms/cm are used.

I STRONGLY advise you to take a look at:

Hello,

Yes, I have read all the above online as well. Again, starts with describing it as clay and then states it’s formed from rock and Pumice.

You will probably note it states:

“After volcanic eruptions, volcanic rocks and pumice accumulate near the volcano. Using these unique resources, Japan has developed rich horticultural products.“

Again, this implies akadama is just a form of pumice.

Can anyone confirm whether akadama is just broken down pumice?

Cutty wrote: Again, this implies akadama is just a form of pumice.

Can anyone confirm whether akadama is just broken down pumice?

It is.
has a fairly good description of its origins (as well as kanuma’s) if you read through the entire thing...

Thanks so much.

My suspicions were correct and what a great site.

Broken down pumice... that’s what I thought.

As a natural Product there is a variation in quality. It is not done in a controlled process. So the conclusion should rather be "A kind of pumice" rather than "Just pumice".

I suspect that all akadama one can find around here is the shallow low quality form. I will try some other options ground locally going forward.

Tropfrog wrote: As a natural Product there is a variation in quality. It is not done in a controlled process. So the conclusion should rather be "A kind of pumice" rather than "Just pumice".

Exactly. There is not just a pumice, there are different pumices.