A rocky argument

And so after a visit to a garden center or a mall, you found a commercially made potting mix and promptly bought it, to be used as media for your succulents. Upon reaching home, you take a photo or two of the product and post it on social media, asking people if what you have purchased is suitable for use for succulents (which makes mo sense at all, considering that you already bought the said product. You are just committing what is termed as confirmation bias- in your mind you were convinced that you were correct in your decision, and would like others to have that supposition confirmed, which feels good). Predictably, answers you obtained are just variations on a theme: that the potting medium you have at hand, which is coconut coir based, is perfect for cacti and succulents, but you need to add some specific amount of sand and/or pumice to make the mix free draining. Satisfied with the answers to your query, you picked up the cutest pots for your plants, had them potted up, and finished it all off with a generous layer of top dressing. Everything went smoothly. Everything looked nice and neat. You have just created some pretty Instagram-mable plants worthy to be showed off to your friends and on social media.

And then weeks later, some of them began showing signs of distress. Panicky, you take pictures of the ailing plants, with cries of help on social media. You get heaps of varying answers, with some even suggesting that you give your plants aspirin. But in reality, none of it matters anymore because your plants are on their fast descent into the world of mush. What happened? While others will diagnose your (or your plants') misfortunes to variables such as watering, heat, and light, very few if at all, will tell you that the potting medium you bought was the culprit. Don't get me wrong- that commercially made potting mix is great for plants, but it is if you were growing vegetables or African Violets instead.

Mammillaria magnimamma. This was purchased in January of this year as an etiolating specimen with a lopsided crown. Barely two months later, the crown has evened up and the plant has grown much flatter.

Such misinformation and misconceptions are easy to trace. Decades ago, producers found out that a heavily organic mix boosts the growth of cacti and succulents, which, from an entrepeneurial point of view, is good for business because the return of investments flows much more quickly. Soon, the said plants will find their way into malls and even groceries. Soon the information regarding the 'proper' mix will find their way into publications, to be held as gospel truth. No one dared question the efficacy of the approach. But here and there, cacti and succulents are declining in health and ultimately turning into amorphous heaps of slime and spines. Again, from an entrepeneurial point of view, this is good for the producers, although they certainly cannot be held accountable for the losses incurred in private collections. But during the 70's or perhaps even earlier than that, some collectors began looking beyond the trays of producers' propagation beds and into the habitat and ecology of these plants. And in there they saw what was mightily obvious right from the very beginning: that most succulents grow on rocks, especially cacti. A back to the basics philosophy is slowly dawning, but the practitioners were only a drop in the bucket to make any ripple. By the late 70's a Romanian collector, Dag Panco, began advocating the use of minerals for cacti cultivation, instead of organics. There may have been others who independently came up with the same approach, but Dag was one of the most vocal apostles and certainly one of the most influential. A copy of Dag's philosophy and views can be downloaded here: http://xerophilia.ro/wp-content/uploads/2013/08/The-Stone-Eaters.pdf

The so-called Frailea carminifilamentosa is considered only as a geographical variant of F. pumila.

Frailea phaeodisca. Fraileas are mostly found in mineral soils in the wild, often on basaltic rocks. Basalt is used in this set-up.

What is it about organic soils that expose cacti and succulents to a wide range of problems? The damning finger can be pointed to an overload of nitrogen contained in such soils. Nitrogen is a macroelement essential for plant growth, but remember that a huge number of succulents evolved in more or less arid habitats where the amount of nitrogen available for root absorption is practically negligible, save for species found in more densely vegetated areas. The plants solved the problem via nitrogen-fixing cyanobacteria that sequester nitrogen from the air and make it available for the plants to use. The other macro- and microelements were absorbed through the assistance of soil microbiota that degrade the rocks present around the roots of the plants. To be sure, the amounts absorbed by the plants are minuscule, but it is enough. Were it not the case, then such plants would have become extinct long ago, wouldn't they? In a soil mix laden with nitrogen, the plants grow quicker and stouter. But along with that growth, the epidermal cells increased in turgidity. Sunburn began to pose itself as a risk. A little too much water and a cactus may burst open, and the disturbing thing here is that no one exactly knows what the tipping point may be, except the plants themselves. You may be cultivating a plump cactus for a couple of years and then all of a sudden it just collapses from a casual watering or drizzle. Environmental factors that are otherwise bearable for plants in the wild, having adapted to those, are now threats to the general well-being of the plants in cultivation. Your plants may look very healthy, but in reality are in a weakened state and vulnerable to attack by pests and rot-inducing fungi. And lest one forgets: organic mixes, even sterilized ones, will always have soil microbiota that are vastly different to what the plants in question have evolved with, and in many cases will even harbor unwelcome interlopers ranging from saprophytic fungi to colonizing ants that bring with them the ubiquitous and difficult to control mealy bugs.

From here, you may be wondering: how about those hundreds of plants being grown in nurseries? If a mainly nitrogen soil is adversarial to these plants, then how come hundreds, if not thousands, are being produced? The answer lies in the simple fact that conditions in nurseries are often more neutral for the plants than those grown in your typical household. Nurseries often have overhead protection for their plants, and in more advanced ones there are even time-controlled misting systems employed. Even in low-tech nurseries, the plants are benefited by meticulous growers that know how to strike a balance, even when their plants are growing in an unnatural state of affairs. The threats brought by excessive nitrogen in the soil are drastically reduced. The plants are in a state of blissful stasis until bought by collectors with very divergent growing conditions and quirks.

While I do not recommend it, cacti can be grown on pure pumice too. Ariocarpus bravoanus subsp. hintonii is shown here. Ariocarpi naturally grow flattish in their native habitats, not the plump, obese plants one usually sees being exhibited in shows.

The so-called Frailea grahliana, which, if I am not mistaken, is currently considered a synonym of F. schilinzkyana. I am of the opinion that both names may be considered synonymous to the variable F. pumila.

Orbea abayensis. I received this plant as a single-branched cutting last Nov. 19, 2017. The growth rate has been rather stupendous.

At this juncture, allow it to be said that in no way I am decrying the use of organic soils by the producers; if they used mineral soils, the cost of production may skyrocket upwards and the growth of their produce will come to a crawl, not to mention the tremendous logistical issues that may arise from their transportation. Although I have problems with producers who are well aware of the advantages of a mineral-based soil and the dangers of using organic-heavy mixes, but still advance the idea that the latter is the way to go, even to novices. I am not a producer, but if I ever venture into such an enterprise, I may use organics mixed with minerals, but will always inform my customers that for long-term growth, a mineralized soil mix is advantageous, whenever applicable.

A plant that has been under my cultivation for more than four years now. It is barely half an inch in diameter and is already producing pups. 

This Haworthia mirabilis var. paradoxa may not look presentable, but it's tough as nails.

This plant, like the one above, is also almost 5 years under my care. I still do not know its name.

Like most everybody else, I have cultivated cacti and succulents in high-nitrogen soils mixed with varying degrees of sand and stones. Most of the plants have since died, a few are adaptable enough to chug along to survive to this day. I have followed advices outlined in books, to the letter. And yet, plants will give up the ghost in just a few months, or two years at the most. While my plants from other families were prospering, flowering, and reproducing well, my succulents just languished and were a perpetual source of confusion and frustration. In due time I realized what was painfully obvious, that the most fundamental part of their cultivation, their soils, was figured out all wrong by ourselves, and so I acted accordingly. Enough of the advices that do not work or will work only for some unknown span of time or conditions. I wanted my succulents tough and to meet that, they should be allowed to develop as naturally as they ought to be. To this day I am still experimenting with a variety of plants, in a variety of minerals, in a variety of conditions- mostly hostile. And I am pleased to inform you that so far, all have been performing very well and there are some that are behaving in a most unexpected, yet welcome, manner.

This Orbea dummeri was given to me also last Nov. 19 as a two-branched, unrooted cutting. One can even say that it's tougher than its own pot.

At any rate, aesthetics also play a part here. Most collectors and casual buyers of cacti and succulents have been conditioned into thinking that such plants have to look in a particular way, even if their picture of perfection is based on nursery-grown plants instead of those from their natural habitats. This means cacti that look like spiny melons. Then again, I should have no business commenting on someone else's sense of aesthetics, but I could not help but ponder over a quandary: here we are trying to maintain a piece of nature in our gardens and backyards, but at the same time we have so far removed ourselves from what nature intended for these plants in the first place. Or are we committing the ultimate hypocrisy?

And yet in the end, remember that a mineralized soil is not for everybody. You may want that plump appearance as opposed to a weather-beaten look, and I will not lose even a minute's sleep over that. Do what works for you. And whether you choose a mainly mineral soil or will stick to the old way of doing things, ask yourself: are you willing to take the risk?

A Mammillaria beneckei? glistens in the afternoon sun.