Question on "Boon Mix" soil

darrellw

According to http://www.bonsaikc.com/bonsai_soil.htm, Boon suggests the following mix:

1 part lava rock
1 part pumice
1 part akadama
1/2 cup horticultural charcoal (per 5 gallons mix)
1/2 cup decomposed granite (per 5 gallons mix)

My questions:

What is the purpose of the charcoal? I've never seen it recommended in other mixes, but is is cheap and easy to got, so I just wonder what it does. Is if for the cation exchange capacity?

What is the purpose of the decomposed granite? It seems too little for "structural" reasons, but I would think it would be pretty inert.

Would a calcinated clay product (Turface and such) be a reasonable substitute for the akadama?

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Carl_Bergstrom

I've used Boon's mix for several years with great results. I believe that the charcoal keeps the soil from going too sour (acidic). I don't typically use the granite because it is not readily available here; I believe that its purpose is to add sharp edges to the soil.

Boon argues that turface and such are not an adequate substitute of akadama.

Best regards,
Carl

darrellw

Thanks, Carl!



I picked up some poultry grit at the feed store, which is quartzite. If the purpose is to add sharp edges, it should work for that.



Too bad, it sure is much more available less expensive!

-Darrell

jjeter

I started using Boon's mix last year with great results. The root growth on a couple of maples were twice that of ones in one of the local bonsai nurseries mix. I don't use the granite either. I get the charcoal at Lowes in the garden section. I don't know why it helps, but I know the trees really put on roots.


Jeff

ALDEVAUX

Furthermore, charcoal is quite frequently used in bonsai soil mixtures in France because it contains some potassium (K) and having been dried out it helps keep a more constant low moisture in the soil. It is interresting for trees which don’t like too much moisture (like pines) and thus prevents infection from the water–loving soil-born fungi pathogens. It can also prevent the reproduction of bacteria which are often the cause of root rot in those soil mixtures that retain too much water.
Finally, charcoal releases oxygen during the draining of the soil mixture and helps make the soil a bit lighter.
Of course, charcoal should always be broken up (i.e. never in powder form) and mixed well in the soil.

Carl_Bergstrom

Thanks for the additional details, Aldevaux. I knew it was a good thing, but I didn't know the details about how it works.

Best wishes,
Carl

007

I've never really experimented with making my own soil. I've felt that I have to learn the basics of care and maintenance before doing so . . . .

But I now feel confident however that making my own soil is the next best thing in the long term (and financial) interest of my tree's and my hobby. This mix sounds like something that is not only easily put together, but sounds like it has the components of what a good soil needs. I particularly like the addition of the charcoal (assuming the information purported here is accurate).

Thanks for posting!

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JTriptow

Just remember, everyone, there are no organics in Boon's mix---so keep that in mind when deciding on a fertilizing regimen.

I have a few trees potted up in Howard & Sylvia Smith's mix with no organics---I am not sure if it is the exact same as Boon's mix (they are Boon's students)---and then I have the rest of my trees in some or another of my own mixes, all of which do have organics (pine bark).

I have only used the Smith's mix for one growing season thus far so I cannot yet tell a huge difference in those trees' growth vs. the others, although they are doing beautifully and have put out a ton of new growth. But I did adapt my feeding regimen accordingly.

Jennifer

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Who knew trees could become an obsession?

rzeles

Can anyone tell me the difference between the Pumice, and Lava Rock. Seem to have many of the same qualities.

I saw Boon's mix which incorporated both. Is this necessary?

Also, where on-line can I purchase these in small enough quantities?

I don;t believe this is a Lowe's or Home Depot purchase.

Thanks.
Ron