Attapulgite and molar clay

[BaKiBonsai]

Last year I was playing around with some hydrangeas for propagating. I had propagated two in some mix of molar clay and attapulgite. I had noticed that the hydrangea cutting that was in a cluster of attapulgite had rooted exceptionally well.

This had me wondering if attapulgite is good for rooting cuttings. I have propagated woody cuttings in perlite, vermiculite, molar clay and sand, but the root formation in the attapulgite was surprising. I have tested the attapulgite I use with wet dry cycles. When it dries it will revert back to a granular substrate.

The hypothesis is: Attapulgite is beneficial for root formation.

I am choosing pyracantha since I had to trim the hedge and since they root well. The time of the year is not ideal for rooting but we will see.

I think I'm in zone 8b, coastal Netherlands.

From left to right the substrates are:

Molar clay	molar clay attapulgite sifted	molar clay attapulgite sifted	attapulgite non sifted	attapulgite sifted
Nodal	heel	nodal	nodal	nodal

I will see how often I need to water, I will try to treat all mixes as that mix needs, so if the molar clay dries out sooner I will water that sooner. The cuttings are outside without a dome in the shade, since that is what I normally do for pyracantha.

I'm curious to see what happens and if it is similar to my hydrangea, which of course is non-woody.

To be honest normally I propagate my pyracantha in coars-ish sand and that works well enough. I don't give them a lot of attention but since I get dozens of cuttings the hit rate is irrelevant to me.

 

[Wires_Guy_wires]

Fun experiment. Where did you get this attapulgite?
I'm always open to new substrate types so if you can give a brand name or something then I'd like to buy some for myself.

 

[BaKiBonsai]

Fun experiment. Where did you get this attapulgite?
I'm always open to new substrate types so if you can give a brand name or something then I'd like to buy some for myself.

Ive read up on it first. It's not commonly used in bonsai but it is used in Agri and horticulture. It holds moisture extremely well, so in the application it can be compared to vermiculite. The substrate is not really oval in shape, more plate/shingle like. When wet it might seem to gum up, but she in dries it reverts back to a very porous structure.

The attapulgite I have is one of the ominous cat litters. It is non clumping and held up to the wet/dry cycles. I would not put it in a bonsai substrate since I feel it would break down too fast. The brand is Agri select and the type is basic grey.

In short, you can buy it at every supermarket in Holland. I just have a small 5L bag for experimenting.

 

[BaKiBonsai]

We just had a large rainstorm, full soak on everything. I took the opportunity to check the substrate.

You can see that the sifted attapulgite still looks granular. The unsifted attapulgite looks ok, but the fines do clump.

When the attapulgite is wet it is quite fragile. I have added a photo of two granules, on one I have applied some pressure to smear it. I don't feel it is a lot more fragile than vermiculite.

 

[BaKiBonsai]

One of the reasons I am interested in attapulgite is that it is a clay based granular substrate. In houseplants pumice is used a lot, but because it has a low CEC advise is to amend it with a bit of clay. I don't like adding a fine particle clay, because it would clog up and restrict airflow. Hence the granular attapulgite, with a claimed CEC of 70meq/100g, where Akadama (also clay based) seems to be 20meq/100g. For surface I find 33meq/100g. (CEC where just found with Google, so could vary between sources and suppliers)

 

[oranjeaap]

So since it's in the cat litter category, is it scented or treated with some kind of anti clumping agent or something?
I've been searching for 100% natural Moler clay in several garden centres and pet shops, but it seems impossible to find.
All of them are scented or have (a bunch of) other chemicals added.

I'm searching for a cheaper and more climate-neutral Akadama alternative. Ideally it's made / mined in Europe to reduce shipping emessions. Moler clay sounded promising. I've been looking into broken LECA balls (gebroken hydrokorrels) eaisly available in Germany but the grain size is usually a but too large for my liking.

 

[BaKiBonsai]

No it is just attapulgite. You can get it as such in bulk for Agri, but I just want to experiment.

Molar clay can be found as Linda moler, at the Ranzijn. It is diatomaceous earth mined in Denmark. I find that by itself it does not promote root growth as much, which in turn stunts growth a bit. Trees do survive in 100% molar though, I just haven't gotten them to thrive in it yet.

As far as I understand there is no replacement for Akadama. The fine root growth you get from Akadama is not found in other sources. If you're looking to find the best other inorganic I think you might want to consider pumice, see https://www.bonsainut.com/threads/michael-hagedorn-on-100-pumice-soil.67966/. In Europe it's also sold under "bims", mined in Germany and Greece.

 

[Leo in N E Illinois]

Generally, unless a clay product has been fired to harden the particles (calcined) the particles will not be stable in a bonsai or a grow pot for a full growing season, especially if your winters include freeze-thaw cycling. So most clay products that have not been fired will fail. Texture is just too soft. This is the failure of most "cat litters" an similar products.

I do not know European products. In USA there is a calcined (fired ) clay product trademarked as Turface that will hold up as a potting media. In practice - it is useful as a media component, personally I've seen best results where it is used at less than 25% by volume of the total potting mix, with pumice or perlite, and fir bark or akadama or other products making up the rest of the mix.

 

[Leo in N E Illinois]

Fossilized Diatomaceous Earth, that has a hard granular structure is an excellent media. It is difficult to locate sources that have not been ground up to fine flour. In USA an OIL DRY product, part number NAPA 8822 is a DE of a fine particle size useful for small size bonsai and seedling mixes. But this is too fine a particle for media mixes for larger bonsai trees. Maidenwell of Australia used to quarry a nice quality and size DE but that was years ago, I do not know if their quarries have been restarted or not.

 

[BaKiBonsai]

Generally, unless a clay product has been fired to harden the particles (calcined) the particles will not be stable in a bonsai or a grow pot for a full growing season, especially if your winters include freeze-thaw cycling. So most clay products that have not been fired will fail. Texture is just too soft.

Yes I feel like this would not hold up for one or two years. My curiosity is mainly about rooting cuttings. I might see what happens over winter in another thread, but I feel it might even "gum up" the pores of pumice and lava.

Recommends clay for CEC, in houseplants application.

The main benefit seems to be whc and CEC.

Attapulgite is also available in calcined form, just less accessible.

 

[BaKiBonsai]

Fossilized Diatomaceous Earth, that has a hard granular structure is an excellent media. It is difficult to locate sources that have not been ground up to fine flour.

Linda Moler is a kat litter that is granular DE. It is very cheap and accessible here. There is no use to sift it since the top of the bag is already big, it is good to water until clear.

For me results in 100% moler (Moler is a mixture of montmorillonite clay and diatomite with the chemical formula of montmorillonite being (Na,Ca)0,3(Al,Mg)2Si4O10(OH)2•n (H2O)) are not as good as baseline, but maybe because I don't fertilize heavily enough.

 

[Leo in N E Illinois]

The single best component for bonsai media is pumice. It can be used with great success at 100%, or in any level of mix. Pumice improves horticulture traits of just about any media mix. Molar clays are unacceptable BECAUSE they turn to MUSH, not because of the CEC and other chemistry issues.

About CEC - I know relatively few growers who pay much attention to CEC. This seems to be a "hang over" from people who were big into hydroponic marijuana growing. Overly technical and likely to lead to over-thinking the basics of horticulture. Not a necessary complication for bonsai horticulture. Sure, it is in the "background theory" of fertilizer programs. But generally not needed to be worried about.

In bonsai horticulture you need media whose particles are stable for at least 2 years, including 2 winters with freeze thaw cycles unless you are only growing tropical species. Here pumice, akadama, fir bark, Turface, crushed quartzite or granite, and other similar products work well. Clay products that have not been fired, (calicined) are unacceptable because they are too soft, not because of chemistry.

Just because "kitty litter " is cheap, does not make it good. If you are going to invest time, often decades, into your trees, it is important to invest in proper media. Pumice is good, soft clays are not.

 

[BaKiBonsai]

Thank you for your input. I agree with what you are saying and I have read the same arguments before. The only remark I would like to make is that the moler clay I am talking about seems quite stable and I believe it has been fired. It is hard and I've had it outside in my climate over winter. It is the same state as before.

I think it has a comparable price point that pumice has, especially if sifting is not an issue. However, for bulk I can get a big bag (1000L or 260gallons) of pumice for less then €150. It would require a considerable amount of sifting, I can't spare the space for the whole operation as of yet.

 

[BaKiBonsai]

Fossilized Diatomaceous Earth, that has a hard granular structure is an excellent media. It is difficult to locate sources that have not been ground up to fine flour. In USA an OIL DRY product, part number NAPA 8822 is a DE of a fine particle size useful for small size bonsai and seedling mixes.

About NAPA 8822, the manufacturer (ep minerals) states the following on their website about diatomaceous earth:
"an absorbent for cat litter"
https://epminerals.com/#:~:text=an absorbent for cat litter and they also sell 100%de cat litter https://epminerals.com/products/blue-ribbon-de-premium-cat-litter.

The product we are discussing is moler clay: "Moler is a natural rock formation that’s found – and mined by Imerys – only on the islands of Fur and Mors in Denmark. It is composed of approximately one-third clay and two-thirds diatomaceous earth. This diatom content gives moler its large specific surface and unique absorption qualities.
Our range of molers for cat litters are essentially calcined grades".

Both seem to be used as "kitty litter". Kitty litter is just a convenient form to get in consumer portions.

 

[Bonsella]

I tried attapulgite in an experiment with prunus and it didn't work. Trees didn't grow as long as previous year in just potting soil.

I think the problem was pH, as attapulgite and also sepiolite have pH 8+. Structure stayed fine after a year of growth.

Some company decided to fire the attapulgite, reducing some of pH and water retention to get more stable peebles. They called it sakadama, but it is as expensive as akadama, so they won't succeed much.

Next season I will try again attapulgite in a seedling of Holm oak, as they like alcaline soils.

 

[99 Mile Creek]

I love seeing experiments with different substrates.

The only thing I may be able to point out is that the heel cutting in one substrate is a confounding variable.

I'd be interested in seeing the results! Keep this thread posted.

 

[BaKiBonsai]

Thanks for the feedback Yes the heel cutting is the odd one out, but it is in a mix where I also have a nodal cutting. It's not really for the competition, just to see how well it works compared to my standard sand setup I normally use.

Interesting that the structure stayed fine, it feels so fragile. Ph is a big downside for most of my trees.

 

[leatherback]

I've been searching for 100% natural Moler clay in several garden centres and pet shops, but it seems impossible to find.
All of them are scented or have (a bunch of) other chemicals added.

Linda Molar, as mentioned. I have it at 10-30% in my blend. Holds water well, promotes firbous roots too. Pure I find it too wet.

attapulgite

I looked into this, and I thought it was too soft. In winter this would become a mush in 2 or 3 frost cycles.

broken LECA balls (gebroken hydrokorrels) eaisly available in Germany but the grain size is usually a but too large for my liking.

Check out rigidur 'Ausgleichsschüttung '. I have used this pure, and blended for a long time. It is rather small instead of large . Prices have gone up A LOT recently. Used to be able to get 50L for under 10 euro. Now you are looking at nearly 20E.

Seramis is another alternative, if you want clay-based

2 years ago I bought half a cubic metre of cactus substrate from Vulcatect, Lava, Bims, Zeolith. Small bags are quite expensive, but if you are a volume user with space to store, or you get a few people together, half a big bag might be priceworth. https://www.vulkatec.de/produktshop/kakteen/295/kakteensubstrat-premium/18013050

As for

there is no replacement for Akadama. The fine root growth you get from Akadama is not found in other sources.

I do not agree with the fine root development to be honest. I have recently tried and did find differences in the internode lenghth with acadama and might add a small percentage to my blend for more mature trees. Not too high, as I find that in my local climate it breaks down to fast (Last winter I have had over 25 freeze-thaw cycles, intermixed with rain, so perpetually soaked pots freezing and thawing)

 

[BaKiBonsai]

Interesting you find molar clay too wet. I do see the same as I don't have to water it daily, which for my current setup is nice. I have a beech in 100% molar and it is not putting out a lot of growth compared to the one in potting soil. I have placed my potting soil on my garden bed which lowers the effective water table in my pot (garden bed "pulls" moisture from my pot by capillary action).

We cannot (normally) get rigidur in the Netherlands, I called gyproc (dutch part of rigips) and they don't ship it. You can get it easily in Germany e.g. OBI.

Vulkastrat has periodic 2 for 1 sales at 123planten, makes it really easy to make a choice. I got 50L for €24.

Might get that 1000L pumice one day, might store it in a raised garden bed and grow in it

 

[BaKiBonsai]

All but the unsifted attapulgite have dried out. We had some rain so I have not watered them myself. The cutting unsifted attapulgite seems to push a bud, see second pic. Sifted attapulgite has a small leave but it is less green, might have been there already.