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I’ve gotten bored of using just 2mm aka dams for my conos. And I see a lot of growers using what I believe to be decomposing granite for their conophytums (I’ve attached an image). Can anyone crack the formula or provide me with some good mixes or conos?

I visited a local grower who uses mostly decomposed granite for growing Lithops and other MESEMBs "Succulents of the Veld" on etsy

No Conophytums but thousands of lithops and other small mesembs. I would guess both plants can use the same soil but different watering schedules.

It was 10% organic, a little perlite and decomposed granite I asked him about it and saw the mix. I don't think he fertilizes ? Soil looks like your picture kinda yellow orange sand.

I’ve also heard of growers using quartz to match the natural habitat not sure if that helps at all

Decomposed granite is composed of quartz and feldspar (along with other minerals). I use it together with pumice, scoria (red lava rock), and a bit of organic matter (peat and/or pine bark, around 10-15%) for my mesembs, including conophytum.

I use my regular cactus mix with extra small pumice, and course sand if I have any.

My regular mix is just Potting soil and about 70-80% pumice
I've been using Fox Farm "Happy Frog" potting soil for the last year and quite happy with it
it contains peat

I've never found a good all mineral mix
and the Decomposed Granite I tried would stay wet too long, it seemed to be too silty

Tim Jackson was using beach sand for his massive collection !!

How has 10-20 percent organic matter worked for you guys? I used the use that a year a ago but lost a few conos which is most likely my fault.

Never had a problem with partly organic soil mixes
Not sure where the idea of organic mixes are bad came from
I've seen some people grow great Mesembs in pure peat

After a couple waterings it looks like pure pumice
C. longum
A flat of Lithops seedlings, growing in Coir and perlite at a commercial nursery Last spring
C. khamiesbergense and in my opinion, looks more like a Gibbaeum
and Gibbaeum neobrownii is more like a Conophytum.

I use about 50% sand from close to a local sand mining operation for Mesembs and seedling cactus. I have used mostly Pumice at one time but didn't like all the dead Lithops and cactus I was getting. Couldn't get the watering right or something.

Good evening dear cacti-friends,

I use pure mineral substrate for all my plants, all kind of cacti and all kind of other succulents.
No organic components and no sand or rock at all.
80 - 90% pumice, 5 - 10% lava and 5 - 10% zeolite.
However, I pay attention to the grain size, small plants - small grain size!
I use grain sizes from 1 - 12 millimeters, 0,04 - 0,47 inch.
Since 1968 I have used different substrates, according to the prevailing fashions.
Since 2008 I have completely switched to the above mixture.
AND the plants and I are very satisfied.

Best wishes

K.W.

Not sure if this is the best thread for this new topic

But what the hell is "Zeolite" used as a soil ?
And, I wish I could try some.

I know what a zeolite is since I know mineralogy, there are many minerals classified as zeolites but I never seen it sold as a soil substitute
also, we don't have local sources for lava gravel, which we call either cinder or scoria

I used to collect red and black lava gravel/sand from some cinder cones on the east side of the Sierras
then would clean it and sell it as a top dressing,
but haven't been up there for a long time

C And D wrote: ↑Fri Nov 18, 2022 5:28 pm >>>
<<<

But what the hell is "Zeolite" used as a soil ?
>>>
<<<

Quote from Uhlig Cactus Nursery:

Zeolites, which are skeletal silicates. Their outstanding abilities are caused by their mineralogical structure.
One of the special properties of zeolites is the high and reversible cation exchange capacity (CAC).
To balance the negative charge of the crystal lattice, ions are adsorbed on the outer and inner surfaces of the crystal lattice.
The cations can be replaced by ammonium or heavy metal cations, for example.
The minerals of the zeolite group are characterized by a pronounced selectivity for various cations.
Particularly strong is the binding to certain heavy metals such as lead, but weak binding to naturally occurring cations (sodium, calcium).
A middle position is occupied by cations such as potassium and ammonium.
The adsorption of, for example, heavy metal or ammonium ions is always associated with the exchange of the existing ions.
During fertilization, nutrients such as ammonium or potassium accumulate in the soil solution.
This high nutrient content, which can not be completely absorbed by the plants as a rule,
is offset by a low concentration in the zeolite.
Part of the nutrients are adsorbed in the crystal lattice of the zeolites and are protected in this form from decomposition / conversion or leaching. When the nutrient concentration in the soil solution decreases, the zeolites release the nutrients so that they can be absorbed by the plants. Zeolites do not change their physical properties through ion exchange.

And You may take a look here: (German) https://de.wikipedia.org/wiki/Zeolithe_(Stoffgruppe)


Best wishes

K.W.

Was playing hooky today so decided to transplant some Conophytum I grew from seed a few years ago and took picture of the soil.

As you can see there are many different ways to make soil and they all work as far as I can tell, not for me but for other growers. I tried more pumice less fine stuff and it was not good. So this works for me.

But what the hell is "Zeolite" used as a soil ? "

I think its useful for completely soil less substrate it will hold Cations of fertilizer because pumice and rock will not. And may act as a PH buffer ?

If you use soil or "compost" that also works to hold fertilizer and buffer PH but with cactus can cause rot if you use too much in a mix. My experiment with mostly Pumice caused problems so not interested in 100% soiless mixes. But some growers have excellent results . Maybe Zeolite mixed with pumice is way better . And maybe depends on your water also ? And yea the Astrophytum is dead but the roots are not rotted and its mostly pumice I checked it today.

We shall do a deeper dive

This article has a wealth of good info
https://cactusculture.com.au/learning-c ... -for-cacti

Kind of expensive, apparently the Bonsai market is the biggest user of it
they have green Zeolite of different sizes

The one thing I like about normal organic potting mixes is the substrate action it provides
I think of it as the milk in the cereal bowl, when you have only pumice, lava and zeolite, it sounds like a bowl of cereal with no milk
What holds it together

I can see Keith's soil mix uses ground up DG as the milk

C And D wrote: ↑Sat Nov 19, 2022 3:44 pmI can see Keith's soil mix uses ground up DG as the milk

What is DG?