AND WHAT ABOUT LAVA...MORE GOOD NEWS!

[MaciekA]

@leus there may ultimately be many tests to determine if something is an adequate akadama substitute, but three very important characteristics of akadama for a "mystery volcanic particle test" are:

1. Ability to be scaled (penetrated by) roots so that further root system ramification can occur than otherwise possible -- do you see roots penetrating through your mystery particle and ramifying within it?
2. Ability to transport water even after scaling by roots -- are you able to show your mystery particle can drain even after significantly broken down?
3. Ability to transport gasses even after scaling by roots -- same as above but for air

These are primarily important if your goal is to "get the refinement results of akadama that bonsai professionals claim are hard to achieve without it". Your goals may differ from those of bonsai professionals.

Another strategy is to use akadama, but in combination with other volcanic soils. My mentors & teachers are testing:

- Akadama mixed with perlite -- good results
- Akadama mixed with smaller pumice -- good results
- Combinations thereof

If you find akadama in Chile please export it to the US. I hear that the reason we're not mining it in Oregon ("Ore-dama") is basically that nobody can raise the capital ($$$$) for the EPA environmental impact study required to start mining. If Japan ever bans export of akadama then we're probably going to have to crowdfund that impact study unless someone gets a windfall of money. In the meantime Ore-dama is going to stay in the ground.

 

[MaciekA]

Side note, to my knowledge nobody has tested to see if roots can scale perlite, but it's such a fragile particle that I'd be surprised if it isn't possible.

Using very small perlite or pumice particles might be a substitute for scaling, but with the caveat that we're then waiting for roots to fill all of those spaces and suffering from poorer drainage while waiting for the tree to catch up with water demand.

Edit: ChatGPT thinks that tree roots can scale (penetrate through) perlite particles, but gives me no references/citations so yeah.

Edit2: Phind's AI disagrees and gives some references to support that notion

 

[pandacular]

I read this article last night and found it to be an interesting claim. I was a bit reluctant as there was very little rigor to the claim. I think I would've found it a lot more compelling if it was more honest about just saying "this is what I do for these reasons" rather than claiming, as @MaciekA says "checkmate".

Personally, the most compelling argument is having to source, sift, and clean one less soil component!

I am curious about specific arguments in favor of lava, as compared to say pumice.

 

[Paradox]

I have never noticed poor root growth on any tree I put in a mix with lava in it.
For pines and juniper, I use lava : pumice : akadama
1:1:1 ratio

 

[pandacular]

I have never noticed poor root growth on any tree I put in a mix with lava in it.
For pines and juniper, I use lava : pumice : akadama
1:1:1 ratio

curious if you've ever planted trees in a lava free mix

 

[mwkohler]

I was least compelled by the tool dulling aspects of the arguments. I see this in woodworking communities as well. Tools are meant to be used, become dull and get sharpened. Get over that and don't use that as a deciding factor for any substrate choice. How quickly my tool needs sharpening is a distant concern as to how well the health is impacted

 

[pandacular]

it's true about the tools, though all things being equal (which the author never claims they are) it is relevant. This is one of the reasons I like carbon steel tools, as they're easier to sharpen. I think sometimes people like to pile on minor arguments even when it's not necessary.

 

[Paradox]

curious if you've ever planted trees in a lava free mix

I have.
When I was new and didnt want to pay for "expensive dirt", I tried sand and pea gravel.
It was very heavy, didnt drain as well as you would think, stayed too wet for too long and the trees showed little to no root growth.

Switched to a more open mix with half lava and half pumice for my pines and the trees loved it.
They grew well and had tremendous root growth.
Added akadama to the mix a year or two later

 

[hemmy]

We are lucky the USGS already measured the chemical composition of cinder from Little Nash crater

For reference, below is the free access to that paper. The geochemistry was analyzed by XRF. Apparently, Boron is difficult to analyze for via XRF and almost impossible with a handheld unit. I was surprised that even in the supplemental material (using the link in the article) didn’t give the specs on the XRF machine used. But it stated that it was at the university so I’ll assume it was a benchtop model. I believe the absence of reported Boron does NOT mean it might not be present in trace amounts. It is correct that the major and minor elements are given with the oxide weight % which do sum to only leave <1% to 1% left by weight. So that leaves us next to find out the trace amounts of Boron for deficiency or toxicity.

https://www.researchgate.net/profile/William-Amidon/publication/302972747_Holocene_volcanism_of_the_upper_McKenzie_River_catchment_central_Oregon_Cascades_USA/links/575974fe08ae9a9c954ee712/Holocene-volcanism-of-the-upper-McKenzie-River-catchment-central-Oregon-Cascades-USA.pdf?origin=publication_detail

 

[hemmy]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7073067/

It should be noted that Boron is an essential trace element for plant and animal life.

From above link, the majority of the world’s ag soils contain 5 - 30 ppm total boron. As you can guess the toxicity level is widely dependent on plant species, soils chemistry and probably numerous other variables. They list 25 ppm as the max that should affect crops. Of course those are crops in the ground not the long-lived tree in the bonsai containers.

 

[hemmy]

I also found it interesting that searches for boron AND lava & boron AND scoria both had top hits for this Michael’s bonsai discussion.

Also, this concern from a cacti grower in 2007.

“The rumor in the past was that the pumice from the AZ mines was high in boron and not as suitable for our uses.”

Pumice/Scoria - CactiGuide.com

Maybe Boron panic is like the satanic panic where it periodically pops up across decades!

 

[hemmy]

Lastly, it is not my intention to poke fun at bonsai professionals who obviously have more data points and observations than I do on the subject. I took a few trees over from a long-time hobbyist who grew in 100% black scoria, including deciduous. I was unable to keep them happy in that media and did observe less than impressive root densities.

It is also worth reading the comments on the original Michael blog post, where it is claimed that some of those nurseries that had toxicity issues switched sources and still use scoria.

At the 1/3rd portion of the APL mix with the constant flushing of irrigation water, it is hard for me to believe that toxicity would an issue.

 

[MaciekA]

If local lava like the stuff from Nash was a problem for any tree it would be a problem for red alder which would fill itself with excess boron or whatever in about 5 minutes, given how lightning fast these trees move water. It is not. Can confirm

 

[NaoTK]

I believe the absence of reported Boron does NOT mean it might not be present in trace amounts.

Unfortunately this isn't how science works. Just reach out to the publishers, the paper is from 2016.

• Boron is water soluble and is only found as borates
• The borates are only found in meaningful quantities in massive evaporate ponds (think California, Gobi desert, Turkey). They concentrate minute quantities of borates over hundreds of miles of brine.
• Oregon's scoria originates from subducted Pacific Ocean basalt and the Little Nash Crater specifically was formed 4000 years ago. Actually, I was surprised how young it is.
• It rains on average 160 days a year in Western Oregon.
• But the boron starts leaching out in a bonsai pot?

 

[hemmy]

• Oregon's scoria originates from subducted Pacific Ocean basalt and the Little Nash Crater specifically was formed 4000 years ago. Actually, I was surprised how young it is.
• It rains on average 160 days a year in Western Oregon.
• But the boron starts leaching out in a bonsai pot?

From previous literature searches(1), boron as a component of oceanic crusts can be sub-ducted and incorporated into volcanic arc magmas. Although due to the fluid-mobil nature of boron, it becomes depleted towards the mantle and from volcanoes that source from deeper magmas. There is apparently at least one or 2 data points of the presence of boron from scorias used in bonsai (Iseli and Mirai(?)).

I agree that it clearly isn’t a widespread problem. Maybe only a very isolated incident from a mined source. I also agree that surface rainfall leeching makes it an unlikely problem for any individually gathered sources.

I believe that any observational deficiencies in root development in 100% scoria or as a precent mix are more indicators of physical characteristics and the numerous other variables that go into bonsai container horticulture rather than any elemental toxicity.


1. https://www.sciencedirect.com/science/article/pii/001670379390008K

 

[Maiden69]

I have seen a few articles on Mr. Onuma's garden. But what I think a lot of people are failing to take into account is that lava is a great component for aeration, it don't hold water too well and this is the reason why I don't use it in my mix anymore. In our heat I need a substrate that holds some water. I do use it for outside the bags in pot-in-pot same as 100% pumice. I also don't like the jagged edges. If I am doing a 1:1:1 mix, I would just double on pumice. Maybe when I move out of Texas I may incorporate lava in the mix again.

 

[MaciekA]

I have seen a few articles on Mr. Onuma's garden. But what I think a lot of people are failing to take into account is that lava is a great component for aeration, it don't hold water too well and this is the reason why I don't use it in my mix anymore. In our heat I need a substrate that holds some water. I do use it for outside the bags in pot-in-pot same as 100% pumice. I also don't like the jagged edges. If I am doing a 1:1:1 mix, I would just double on pumice. Maybe when I move out of Texas I may incorporate lava in the mix again.

This is very true and it would be interesting to see how your requirements change if you do change location. I would say in Onuma's case (and in my case too) the poor retention is actually goal though, as opposed to a factor to be avoided. I can't speak for Jonas except to say that he talks about results / quality / morphology being the highest priorities for his work (in media and in person), and I haven't seen him gripe about the lifestyle impact of needing to check trees for dryness multiple times a day regardless of the soil he is using -- maybe he's talked about it in advice for other people, but he's clearly accepted being glued to the watering hose during summer for his own projects, or the burden of having to find solutions for when he travels. So if you're a full-timer anyway, it's a bonus if the results you get are better than pumice. At Shohin School this year, Jonas told me he's settled on lava as a better option than pumice for his pine growing needs.

I have accepted the same short-retention-driven constraint to my lifestyle in the summer because I grow black cottonwood in full sun (don't do this unless you want to be within a few feet of a hose all summer). Onuma and folks like him can disregard lifestyle impact to some degree because they are full time in this game. I'm fine with having to account for watering more often during the narrow set of weeks when it's more than once a day in lava -- I'm not in Texas though so perhaps it is only because it's a narrow set of weeks. That said, I'm not growing everything in 100% lava like Onuma is -- just non-JBP pines, and even in lava, some of them sip, especially once hardened. Post-hardening, a young lodgepole pine can go to 100 - 105F every day for a week and still get by with about 1 watering on average per day. In a pond basket!

 

[Maiden69]

This is very true and it would be interesting to see how your requirements change if you do change location. I would say in Onuma's case (and in my case too) the poor retention is actually goal though, as opposed to a factor to be avoided. I can't speak for Jonas except to say that he talks about results / quality / morphology being the highest priorities for his work (in media and in person), and I haven't seen him gripe about the lifestyle impact of needing to check trees for dryness multiple times a day regardless of the soil he is using -- maybe he's talked about it in advice for other people, but he's clearly accepted being glued to the watering hose during summer for his own projects, or the burden of having to find solutions for when he travels. So if you're a full-timer anyway, it's a bonus if the results you get are better than pumice. At Shohin School this year, Jonas told me he's settled on lava as a better option than pumice for his pine growing needs.

I have accepted the same short-retention-driven constraint to my lifestyle in the summer because I grow black cottonwood in full sun (don't do this unless you want to be within a few feet of a hose all summer). Onuma and folks like him can disregard lifestyle impact to some degree because they are full time in this game. I'm fine with having to account for watering more often during the narrow set of weeks when it's more than once a day in lava -- I'm not in Texas though so perhaps it is only because it's a narrow set of weeks. That said, I'm not growing everything in 100% lava like Onuma is -- just non-JBP pines, and even in lava, some of them sip, especially once hardened. Post-hardening, a young lodgepole pine can go to 100 - 105F every day for a week and still get by with about 1 watering on average per day. In a pond basket!

In my limited knowledge I try to err on the side of caution. For all the trees that I am developing, I use a free draining substrate, but one that holds water and will not compact or collapse with time. Reasoning comes from an old post from Jonas about his use of colanders. That the mayor benefit was the added oxygen, but at the expense of more frequent watering and fertilizing in order to get the maximum benefits. Right now I have only 2 trees in pots, both are ficus, those are in 100% akadama. I water several times a day, sometimes even if the tree don't need it, just to bring a rush of air into the roots with it. I am using Monto Clay and Bonsai Block from Bonsai Jack along with pumice, no top dressing on developing trees. Substrate holds decent amount of water and evacuates quickly. I try not to use organic fertilizer so as not to clog it up. I bought some but ordered some tea bags to place it inside, just waiting for the heat of summer to die down to start pushing for fall.

That's the mix for bald cypress, since they will be inside water 80% or more of the year I use around 70% pumice.



That's the mix for deciduous, 50/50 Bonsai Block-Monto Clay with less than 10% pumice, or no pumice at all.

 

[hemmy]

I believe the absence of reported Boron does NOT mean it might not be present in trace amounts.

Unfortunately this isn't how science works. Just reach out to the publishers, the paper is from 2016.

Good idea! I did reach out this morning and got an amazingly quick response from Dr. Cashman and Dr. Deligne who were able to get an answer from the other author, Rick Conrey, who did all the XRF. The response is below. The absence of reported Boron from the samples was because it was not analyzed for, but not just because Boron is difficult to measure with XRF, but also because the preparation method involved lithium borate. I guess measuring difficulty with X-ray methods also precludes me from piggy-backing some samples on my next XRD sample run, lol. In the end, this is mostly academic since as we've discussed, I also don't think Boron toxicity is problem with most scorias.


The XRF data was determined neither with handheld nor benchtop, but with 4.2 and 2.5 kW WDXRF spectrometry (those are large floor models, not bench models). Boron was not looked for because 1) the samples were dissolved at high temperatures in Lithium borate flux to generate glass, thus precluding any quantitative B determination, and 2) Boron is extremely difficult to measure well with X-ray methods; detection limits are high, in the range of weight percent, not parts per million as for heavier elements. Plus the X-ray wavelength is so long that consistent surface preparation of the samples is critical, or scattering at the sample surface will be the major signal determinant. That's in addition to the normal difficulties with very light elements: extremely low X-ray production rates coupled with extremely high absorption rates from all surrounding elements. Boron determinations are difficult in general for rocks, I hesitate to suggest a method for scoria. Searching the literature for B (or B isotope) determinations would turn up analytical methods in use, I have no direct experience other than with colleagues who do have such and who report many difficulties.

 

[NaoTK]

Good idea! I did reach out this morning and got an amazingly quick response from Dr. Cashman and Dr. Deligne who were able to get an answer from the other author, Rick Conrey, who did all the XRF. The response is below. The absence of reported Boron from the samples was because it was not analyzed for, but not just because Boron is difficult to measure with XRF, but also because the preparation method involved lithium borate. I guess measuring difficulty with X-ray methods also precludes me from piggy-backing some samples on my next XRD sample run, lol. In the end, this is mostly academic since as we've discussed, I also don't think Boron toxicity is problem with most scorias.


The XRF data was determined neither with handheld nor benchtop, but with 4.2 and 2.5 kW WDXRF spectrometry (those are large floor models, not bench models). Boron was not looked for because 1) the samples were dissolved at high temperatures in Lithium borate flux to generate glass, thus precluding any quantitative B determination, and 2) Boron is extremely difficult to measure well with X-ray methods; detection limits are high, in the range of weight percent, not parts per million as for heavier elements. Plus the X-ray wavelength is so long that consistent surface preparation of the samples is critical, or scattering at the sample surface will be the major signal determinant. That's in addition to the normal difficulties with very light elements: extremely low X-ray production rates coupled with extremely high absorption rates from all surrounding elements. Boron determinations are difficult in general for rocks, I hesitate to suggest a method for scoria. Searching the literature for B (or B isotope) determinations would turn up analytical methods in use, I have no direct experience other than with colleagues who do have such and who report many difficulties.

Well done! Now ask them their preferred mix for JBP