Potential Soil Substitutes?

Hello All,

I’ve recently gotten into bonsai (8months ago) and I’m very excited as we are coming up on my first re-potting season. But the more research I do on soil mixes for your bonsai, the more different soil ‘recipes’ people have and recommend. I know Mirai recommends pumice, lava and akadama but each of those elements aren’t always the easiest to find. I have watched the nursery stock series video and soil video from the bsop series. So I understand I need a balance of H2O and O2, and CEC.

Having said that, I am crushing lava rock I bought from the hardware store. As for pumice and akadama, I am having a hard time. I live in Toronto, Canada.

What do other people use for soils?


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If you are having trouble finding pumice, perlite is a great substitution. Basically a factory made version of pumice. Only issue is that it floats when dry, so watering can be tricky at first (and if it ever dries out).

As for akadama, there aren’t many substitutes out there. Lots of people are experimenting with diatomaceous earth, which is found in some versions of oil-dry from Auto Parts stores in North America. It’s similar, but not 100% and not known to scale like akadama does. Other people like decomposed pine or fir bark (make sure it is decomposed). Roots can grow into it, but it’ll break down passively over time.

You can find pumice and akadama pretty easily on Amazon. They’re not cheap, but unless you have an awful lot of trees, the expense is trivial compared to the time and worry you will invest in your trees over the years. You’ll do it eventually, so you might as well do it now.


I’ve wasted a lot of time experimenting with soil substitutes; Turface or Soil Master Red (for clay), river sand or grit for aggregate, and perlite. Even some bonsai shops will sell “soil conditioners” which are just big bags of unsifted rocks. I never used Akadama, and always heard bad things about it. But some of the more prolific success I’ve had with my meager collection has thrived using primarily Akadama particles. If you can find a good source, it’s worth the investment. I never thought I would say that…ever.

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Anybody have a good muck recipe? Ryan uses Keto (sp?), but I’m wondering if there’s something else you can sub for that (not even really sure what it is exactly, other than some really dense soil). Wondering if some really rich topsoil would work, or peat. I’ve got some beautiful collected stone slabs, and would love to plant on them, but the muck is my missing component. Currently taking suggestions.

There is a lot of recipes for “muck/keto” in other online forums.
Keto is from the bottom of lakes and rice fields. It dries rock hard and almost water resistant.
Maybe find a lake or pond to harvest some muck.

@nmhansen Ryan mentioned that pumice is the big water retaining part of the soil. The idea that perlite, a soil additive I previously added to my soils for aeration is the element now being used in my bonsai containers to retain water. Mind blowing. Thanks for the help. I am really starting to/trying to understand how the soil components work with the tree instead of just planting plants in dirt in a pot.

I collected some pine and fir bark from the forest, chopped it up and sieved it. I did this because I have read about people using pine and fir bark. I am assuming mine is not decomposed. Is there a way I can go about doing this?

@ChuckP Ya, I had see it on amazon, but as you mentioned I wanted to find either a cheaper and/or more bulk option with the future in mind.

@chatt_bonsai You never used “Akadama”? I think you meant to say something else.
How do you know if its quality akadama or not? I drove into the city and bought a small bag of akadama from a bonsai shop but it was pricey and I know I will need more. If its worth the investment I may have to make another trip. Just need to do my research first and save my pennies if I decide to go the akadama route.

Does anyone use Haydite? That is another soil that is sold from the bonsai store and I have heard of people using it before, but I am not quite familiar with its function in the bonsai container.

If you want to go by what Ryan says, he mentions Haydite at about 45:38 in the video below.


He says it’s a fired component and when you fire something, it loses its cation exchange capacity and as such, haydite might be a substitute for pumice.

I don’t use it, but I know that it’s an expanded shale product. It’s hard to break down, holds some water, but doesn’t seem to have much in the way of CEC.

Might be decent substitute for lava rock, though it sounds like it’s meant to add aeration to soil.

I’m lucky and can find lava rock and pumice very easily, so I haven’t really looked into substitutes for those. I’m mostly stuck with finding a cheaper alternative to akadama. DE it’s working wonders right now, but I don’t think I’m getting the scaling of the roots that I need. I’ll give it some more time though.

Hi @Malcolm,

One cheap substrate I use (especially on collected trees where they might be in bigger pots/tub/box for a few years) is cat litter (“kittydama” :smirk:). It has to be the right stuff (fired clay, and not antibacterial) but it’s similar to Molar, just cheaper.

I use Akadama, pumice, lava, pine bark as well and sometimes cut a more standard mix ratio of those with cat litter. If you’re on a budget, look into it. Harry Harrington has written about it, just google his name and “cat litter bonsai”. :+1:t2:

The right kind of kitty litter is one that contains diatomaceous earth (which, as you mention is very similar to Danish Moler).

As far as I know, there isn’t a brand kitty litter sold in North America that is derived from DE (maybe there is, so cross your fingers). It’s much more common in Europe. In North America, the easiest way to get DE is from some brands of Oil-Dry sold at auto-parts stores.

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@Malcolm a link to a high quality and reasonably priced pumice General Pumice Products

Also check out Bonsai Jack, they have quality presifted components and mixes, prices are decent, also they can be found on Amazon. Bonsai Jack

@Malcolm @el_cheezer I use haydite currently in my mixes. It can either be a substitute for pumice or lava. Both are relatively neutral in pH, both have low/poor CEC, both are porous and serve as aeration and water reservoirs. Lava probably adds more trace minerals than pumice. I like the appearance of haydite better than pumice, but I use what is available locally and inexpensively.

@Ralph I also have used DE for several years in my mixes. I source mine from Napa it’s called Floor Dry or Oil Dry there and has a part #8822 affixed to it. I have had good success using this on many of my trees. The exception being azaleas, I’ve lost some really nice ones when I switched to DE. Others I know have had success with azaleas. DE definitely takes longer to scale down, notice I said “longer” and not doesn’t or never. It does scale but has taken 4+ years in most of my mixes or when added to a mix on an aggressively rooting species like bald cypress. DE is a good alternative, I like it. I also really, really, really like akadama. I have noticed all my trees do better with Akadama mixes.

I suspect its for several reasons. It holds water better and longer. DE tends to dry out more quickly and loses water to evaporation. I have used some soil test kits and Akadama also buffers soil pH better, it creates a more stable pH in the containers. Important if you have hard or alkaline water, as I do. I frequently have to use Miracid and other soil acidifiers and supplements for my more acid-loving species because of chlorosis. This has not happened with my Akadama mixes, I’m currently adding an venturi injector to acidify my outdoor tap.

@Malcolm I have mixes that Ive made for over a decade, to save on costs. Cough The reality is this… I spend considerable time sourcing material, I then spend TONS and TONS of time sifting and separating, I then have to mix the aggregates which also takes MORE time. I lose out on time with my trees and time I could spend on other things, and I still have some percentage of the aggregates that I “waste,” which are the fines that I amend the garden with. I’m soon to go with presifted and sorted aggregates, money well spent + time and frustration saved. That’s a WIN if you ask me.

Anyways, sorry for the long reply everyone. I’m going to attach a few more things here that might be of use for assisting you all in the soil conundrum.

American Bonsai Soil InfoAmerican Bonsai Soil Info they also sell mixes and individual components. More pricey than Bonsai Jack, nearly same quality.


Recipe from Michael Hagedorn- The muck we are using now is a three part mix of sphagnum moss (not peat), akadama dust/fines, and corn starch in roughly equal parts. The corn starch is microwaved/cooked until it has a jelly-like consistency, then added to the mix. The starch holds it all together and firms up even more after a day or two.
This muck has, in my opinion, better permeability and water retention than the keto from Japan.

Michael has had great success with his slab and flat surface plantings. I recommend his blogs to see his results. :thinking:


Hi Malcolm,

I am in Montreal. I use Chabasai that you can buy from the SBPM or SBPQ here in Quebec, It is a product imported from France with characteristics very similar to Akadama but much better resistance to freeze/thaw. I now use 40% Chabasai, 40% Qualisorb (which is 100% pure Diatomaceous Earth or DE for short, very economical and available at Canadian Tire - has one of the best CEC values) and 10% composted pine bark. I use the pine bark to add more air spaces, increase humidity, decrease the pH and serve as substrate for microbial flora in the pot. In the past I used 100% DE or DE with pine bark or coconut shells. Your substrate/watering/fertilizing must be adapted to each other, particularly if you use chemical fertilizer in liquid form as you can find out from the thorough discussion on the subject by Walter Pall (just google it). At the same time, you can and must adapt your substrate to your lifestyle, for example during summer you cannot be there to water a second or third time so it is better to have some more water retention in the container with the pine bark without affecting the balance of water and oxygen too severely. My 2 cents.


This is so true. I’ve tweaked my mix to work well in the Arizona heat, which is the harshest time for me trees. Winter watering gets a little weird, because my mix holds a bit more water, but making a more"year round" mix meant my trees were drying out too fast in the summer.

Definitely think about what your trees need, what you are capable of providing, and use those things to make an educated decision.

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You read me right @Malcolm …I’ve never used Akadama before this last growing season. I had just heard so many nay-sayers talk about how it was a waste of money, and there were more effective substitutes. While that may be true, and while I also have had success with other materials, I planted several trees (2 conifers, 2 deciduous) in straight akadama, and they grew incredibly well. I wish I had tried it earlier. Now I do something similar to the “Boon” mix - 1:1:1 akadama, pumice, lava and have had great success with it.


I’ve found a new (in my opinion - I haven’t heard it mentioned on here before) replacement for pumice. Would appreciate opinions on it’s likely efficacy before buying / testing

Calcium silicate (a composition of materials such as larnite)

Sold in the U.K. as a non clumping cat litter

According to Wikipedia calcium silicate is slightly water soluble and is used to treat acidic mine waste. Both of these could be a potential issue in bonsai - leaching Ca2+ into the soil (some is needed) and raising the pH. I see those as potential issues and not big red flags so it might be good to run some trials with lower value stock.