The following article is dedicated to this theme, which goes into detail about the cleaning and sterilization of vases (plastic and terracotta) and the materials used for the substrates (pumice, lapillus, gravel, etc.) which have been set aside after the last repottings carried out in recent months. (…)

Premise

The recycle of pots and aggregates is common practice. Obviously it is not always possible to recycle everything, but a good part of what has been used for the cultivation of our plants can easily be used for future repotting, as long as the materials are thoroughly cleaned and sterilized. Clearly, broken pots and peat must be eliminated since they have exhausted their “cycle” (the peat has already been exploited and would be of little use), but the first major distinction to make is whether those materials (pots and substrates) have given hospitality to plants in perfect health or if they have hosted plants that have died from rot or are otherwise affected by parasites. Let’s see everything in detail by dividing the two categories: vases and inert materials.

Recycle pots

Recycling pots, especially if you use plastic ones, is a must. First of all, we contribute (in our own small way, clearly) to the reduction of plastic production; secondly, you save money, because plastic vases are very long-lasting and can be washed extremely easily. If you use terracotta vases, recycling also takes on an additional value: you can reuse particular vases, perhaps “valuable” or in any case large and therefore expensive.

 PLASTIC POTS  – If no plant has died in the pot, you can limit yourself to a thorough washing with warm water and a detergent product. Even in these cases, however, adding a little bleach is always useful to eliminate germs and bacteria that may have formed while the vases were stacked waiting to be recycled. For washing, all you need is a sponge with a slightly abrasive side and a little bit of patience. Important: if you use bleach you should wear rubber gloves, the classic gloves for household work!

However, if a plant had died in the pot, you can decide to throw away the old container to eliminate the risk that the new “tenant” could contract the same fungus, or carry out a more in-depth operation. In this second case, rinse the vases well, then place them in a basin containing water and bleach and leave them to soak for a few hours (even a whole night if you want). After this period of time, wash the vases carefully, trying to reach every internal corner, with a slightly abrasive sponge, always with water and bleach. At the end, wash a second time with soap and water and rinse thoroughly. Once the vases are clean it is advisable to leave them in direct sun for at least a day: even intense sun helps to sterilize.

 TERRACOTTA VASES  – Unlike plastic vases, terracotta ones are porous: this is why cleaning is longer and more difficult, since an old terracotta vase may have limescale or greenish stains. If the vase is already clean enough, you can wash it carefully with soap and water and a drop of bleach. If, however, the vase is marked by limescale stains or moss residues, it can be immersed in a basin with water to which we add lemon juice, or bicarbonate or vinegar. We leave the vases to soak for a few hours and give them a vigorous wipe with a sponge, using the same water in which they were soaked. Once the “signs of old age” have been removed, proceed by washing the vase with water and soap and then placing it in direct sunlight for at least a day, to ensure that all the water evaporates from the porous walls.

If a plant has died from rot in the terracotta pot, there are two cases: if the pot is already old, chipped or of negligible value, it can be thrown away. However, if the vase is valuable, large or has a certain value, it can be cleaned thoroughly and then sterilized. The cleaning procedure is the same as described above, while as regards sterilization you can use the old boiling method (obviously if the jar is not huge): you place it in a cooking pot, fill everything with water and turn on the heat, leaving the vessel to “cook” until it boils. Once the water boils, turn it off and leave the jar to soak for at least twenty minutes. Alternatively, you can immerse the terracotta pots in water, adding an “aggressive” sanitizing solution, such as bleach (leaving them to soak for at least an hour). Once the vase has been cleaned and sterilized, it is placed in direct sunlight for at least a day, so that it can dry completely.

The procedures described above are applicable, up to a certain point, also to enamelled pots usually used for bonsai. In this case, they are usually valuable vases, enamelled on the outside and porous on the inside: all the more reason it is a shame to throw them away. A word of caution when dealing with this type of vase: in these cases it is best to avoid boiling (which could ruin the enamel), preferring bathing in water and bleach. Likewise, it is better to avoid abrasive sponges that could scratch or ruin the enamel.

The choice of vase? Here’s everything you need to know…

Recycle inert

In the cultivation of succulent plants, whether cacti or leafy succulents, many inert materials are used, i.e. materials useful for draining the substrate. The aggregates can be porous or smooth, each one has certain properties and the choice is truly remarkable and it is good to know them to choose the most suitable ones for the mix we want to create. In this article you will find an examination of most of the materials useful for preparing soil for succulents. Having said this, when you dig up the plants and thoroughly clean the roots you will find yourself with entire basins full of the old substrate, which, if done correctly, contains a lot of inert materials. Unlike peat, which becomes depleted over time and with the absorption of nutrients by the plant, aggregates retain their usefulness and this is why (as well as saving money) it is certainly a good thing to recycle them.

As with pots, however, it is important to point out that the substrate in which a plant has died or in which parasites have been found (for example, root cochineal) must be eliminated. The pots, as we have seen, can be washed and sterilized, but in the case of the substrate it is better not to take unnecessary risks: if a plant has rotted in that soil or if we have found parasites in that soil, we throw it away without hesitation.

If, however, the substrate has been recovered from the repotting of perfectly healthy plants (it is essential to carefully check that no parasites nest among the roots) we will be able to recycle it without problems. The first thing to do, once all the old substrate has been collected in buckets or basins, is to sift it, using a fine mesh sieve, so as to separate the actual aggregates from the peat, dust or clay. The fine part, now used, must be eliminated, while the aggregates are deposited in a clean container. Once all the aggregates have been obtained, we move on to sterilization, which is useful even if no plant has died in that substrate.

To sterilize inert materials there are different methods: for example, they can be spread on a cloth and sprayed with a non-aggressive disinfectant (let’s avoid bleach) then letting everything evaporate, or they can be boiled, exactly like terracotta vases. Finally, they can simply be spread out on a nylon sheet and left in direct sunlight for at least a week, allowing the sunlight and air to give a good cleaning to pumice, lapillus, gravel, quartzite, etc. In essence, the sterilization process of the aggregates is mild and rapid since if there were no parasites or bacteria present in the substrate that caused the plant to rot, it can simply be deduced that that soil was and is perfectly “healthy”.

Once the cleaning and sterilization operation has been completed, the aggregates can be put aside or used immediately for the composition of a new substrate, adding fresh peat, earthworm humus or any other element useful to the plant that will be repotted (for example chalk for some cactus genera).

Important note: when taking the plants out of the pot it is essential to thoroughly check their health and check that no parasites are nesting among the roots (here you can find a video on root mealybug). Only in this way can we have reasonable certainty that those aggregates can be recycled without problems. When in doubt, it’s better to throw everything away: it would be a shame to put the plants at risk just to save a handful of pumice or lapillus!

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Correlated articles

• Diseases and pests: all the articles
• Choose the right pot
• Substrates: all the articles
• Inert and materials
• Repotting: all the articles

© The texts, videos, photos and graphic elaborations of the site “Il fiore tra le spine” are original material and are covered by copyright. It’s forbidden to reproduce them in any way.

L'articolo Pots and inert in the cultivation of succulents: can we recycle them or is it better to throw everything away? proviene da Il fiore tra le spine.

Anyone who has been cultivating succulent plants for a long time – whether they are cacti or other succulents such as Crassula, Euphorbia, etc. – knows well what should be done after transplanting, and he certainly knows that these plants should not be watered immediately at the end of this operation. However, there is repotting and repotting: there is the “invasive” one and the one that involves simply moving a plant from one pot to another. There is repotting which involves total cleaning of the roots and that which involves only a superficial cleaning of the old soil. In short, there are many situations and one can proceed in various ways. However, there are some fixed points and they must be respected if we want to avoid the risk that following this operation the plant will go into stress or, in the worst case, die following a rot that started right from the roots.

This is why this article, certainly useful to the novice, can prove equally useful to the long-term grower. In fact, here we will see the various types of possible repotting, the precautions to use and, above all, what to do (not only from the point of view of watering) once the repotting of a succulent is finished. (…)

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L'articolo Repotting a succulent plant: what to do afterwards and how long to wait before wetting the soil proviene da Il fiore tra le spine.

Hated, mistreated, seen with contempt, often carefully avoided. Expanded clay and peat are two highly contested and criticized elements among growers of succulent plants and cacti in particular. Net of the chatter from the Internet, are these really two materials that should be forgotten with the cultivation of this type of plant? The question remains open and every grower has his reasons, but there is a fact: on the Net, as far as expanded clay and peat are concerned, everything is said. Above all, it is said that they retain humidity excessively and for this reason they should be banned from the cultivation of cacti and succulents in general. It is said that they favor the onset of rot, that they do not let the roots breathe and much more. Why then do many serious nurserymen (and expert growers with them) still make extensive use of those elements? Simply because, as in many factors of cultivation, the point is not so much the material itself, but the type of use that is made of it.

In this article, let’s try to understand if expanded clay and peat are really such “dangerous” materials for cacti and succulents, if and how they can be used and what their real pros and cons are. (…)

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L'articolo Expanded clay and peat: are they really two materials to avoid when growing succulents? proviene da Il fiore tra le spine.

Full sun? But what do you want to know, the window on the landing is enough! Substrate? I buy it ready at the supermarket, it’s perfect. The pots? The smaller the better: never leave more than half a centimeter between the plant and the edge of the pot… And so on, by dint of amenities, false beliefs, hearsay phrases that rapidly becomes dogma because… because it was said by that guy on Facebook and it’s immediately clear that he’s someone who knows about it because his videos has the right lights and Kubrick seems to have done the editing for him. Joking aside, how much nonsense do we still have to hear today about the cultivation of cacti? How many improvised “influencers” ride the crest of social media driven by the Mistral of likes (yes, likes, which in jargon are called “the metrics of vanity”…) and, supported by legions of followers and big thumbs up, they deliver lessons and conferences winking from the monitors, revealing “5 fantastic tricks you don’t know about cacti” or “how to go from seed to flowering plant in 35 seconds”. Or, with an attitude halfway between the conspiratorial and the revealer of esoteric secrets, they promise to teach you everything, absolutely everything about the cultivation of these splendid plants. Then, perhaps, you dig a little and discover that the influencer on duty has been growing cacti for 2 or 3 years – a gift from grandmother -, keeps them next to the PC or television (“you know, they absorb magnetic rays”), he can’t distinguish a Rebutia from a Begonia and has never bothered to leaf through any book on cacti and succulents. There are also influencers for plants, right? No. There are likeable and well-prepared characters, there are pretty faces who know something, but there is also a lot of “fluff” (forgive the old reporter’s term). So much wrong information, so much confusion and so much unpreparedness.

So, without any desire to offer you “The Word” with this article, here is a handbook, a list of ten things you need to know (or you should already know!) if you really want to cultivate your cacti in the best possible way. Without tricks or deceptions: here we are at the fundamentals, come on. But without these you go nowhere. And I am convinced that even those who, scrolling through the 10 points will say “ah yes, I know” ten times, will find in this handbook a useful tool for reviewing, asking themselves a few more questions and pushing themselves to improve. And rest assured, what follows does not come from the web, but from 30 years of experience in the field, of experiments and failures, from discussions with growers and scholars far more expert than me and from reading a few dozen manuals in Italian, English, French, Spanish (and also German, although in that case, I confess, I limited myself to photographs and captions, not knowing the Teutonic language!) (…)

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L'articolo How to grow cactus: the handbook with the 10 things you absolutely need to know to avoid mistakes proviene da Il fiore tra le spine.

Recently, on the social channels connected to the site, I published a short video in which I repot an Astrophytum asterias in a substrate composed solely of Seramis. Following that video, many asked me for information on this particular material with its characteristic orange colour, in fact little used in the cultivation of succulents and not easily available in small nurseries. I have had the opportunity to use Seramis in the past in the cultivation of some cactaceae and my experience has been decidedly positive (although, as a porous inert material, in my opinion pumice remains the best material ever) and it is also for this reason that I recently employed it for the Astrophytum subject of the video (video that you can also find at the end of this article).

Answering many questions received in recent weeks, let’s see in the following article what exactly Seramis is, what are the strengths and weaknesses of this material and what can be its use with succulents and, in particular, with cacti. (…)

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L'articolo Seramis, an alternative material for growing cacti and succulent plants: pros and cons proviene da Il fiore tra le spine.

We see them in detail in the following article (…).

Premise

By the time of June, two first dangers for succulent plants should have passed by now, if we have done everything correctly (and regardless of the fact that this spring has been quite anomalous). I am referring to the danger of cracks on the cacti stems and that of burns following a late or “hasty” exposure. Once the cacti have resumed vegetating after the winter stasis, in fact, it may happen that following the first waterings (if too abundant or too close together) the stem “splits”. In this period of the year, even in the case of a wet and cold spring like the latter, cacti and succulents should have already received at least two or three waterings and the stems of the plants should have swollen. If the recovery has taken place gradually and the plants have returned swollen, the risk of stem splitting for this year can be said to have been archived.

In some ways similar speech in terms of exposure: to date all the plants should have been in their ideal location for some time now, where they will remain until autumn. In other words, those who kept cacti and succulents in the basement, entrance halls or garages should have moved the plants to full light (or half light depending on the genre) by now, under penalty of etiolation. Abruptly moving the plants now, with the June sun starting to get stronger, can expose the plants to the risk of severe burns on the stems. Whether the spring is cool or not, whether it is humid or not, the plants must be gradually accustomed to intense sun or direct sun and this must be done between the end of March and the beginning of April. In this way cacti and succulents are able to get used to direct sunlight very gradually, strengthening the epidermis well before the summer sun hits them. If you haven’t moved your plants yet, do it immediately but repair them with shading nets (especially during the hottest hours of the day), otherwise the first burns will begin to appear in the coming weeks!

Maximum air

Having exhausted the necessary premises, which are nothing if not common practices in the correct cultivation of cacti and succulents in general, we recall that the main element of cultivation, at this point, is trivially… the air. Trivially, because this element is often underestimated, or even not considered at all, taking it for granted. The air, on the other hand, is the main factor for the healthy growth of any plant and in this season, with temperatures starting to rise significantly (on sunny days in a completely open greenhouse it can easily exceed 40 degrees Celsius already in June, let alone August), the plants need as much air circulation as possible.

Anyone who cultivates in a very large professional greenhouse will have to open the structure as much as possible, raising the side curtains and possibly leaving the front and rear doors open. Those who cultivate on balconies and terraces should have no problems whatsoever, while those who cultivate in those small greenhouses covered with a transparent cloth must do nothing but… get rid of the greenhouses, remove all the plants from there and disassemble the greenhouses, which can return comfortable, at best, in winter (although they are still not the best due to the limited air circulation they allow). In this period, if we keep the plants in this type of structure, even by raising the openings in the transparent sheet to the maximum, we will still not be able to ensure the plants the air they need, and with high temperatures and humidity the risk of “boiling” plants or creating the ideal environment for the formation of molds and fungi is very high. Therefore, if you haven’t already done so, remove the greenhouses (which can be simply used as shelves) and, since the plants will not be sufficiently accustomed to the intense sun, shield them with a not too light shading net.

The importance of air and light for succulents plants.

Watering and aestivation

In this period, even if the temperatures are not yet very high this year, it is advisable to increase the frequency of irrigation. If the days are sunny and the weather does not predict rain for the following days, it can be watered once a week. The pace can also be increased to two waterings per week for some species or succulent leafy plants if slight wrinkling is noted. As always, the basic rule is to water only when the substrate appears dry and, if in doubt, postpone it. Beware of the hot months, i.e. July and August, when the difference between the maximum and minimum night-time temperatures is minimal: in conditions of persistent heat, many cacti and many succulents can go into aestivation, slowing down or blocking their growth. In these periods it is better not to water at all, since the plants do not absorb water and the soil would remain moist for too long, with the risk of root rot being triggered.
A few more waterings will have to be reserved for very young plants and seedlings, which are not yet able to tolerate long periods of drought in hot conditions and, at the same time, “push” more than adult specimens.

On the phenomenon of aestivation you will find a specific article at this link.

Fertilization and treatments

In June it is still possible to fertilize succulents. A fertilization is enough, assuming that a first fertilization was given in May or April. If the plants have been repotted a few months ago it will not be necessary to add fertilizer to the water, but if we are dealing with specimens that have lived in the same soil for years, an extra fertilization can be useful to replenish the nutrients once present in the substrate. Pay attention to the product (whether it is in powder or liquid form, it matters little), which must be specific for succulent plants and therefore low in nitrogen and rich in phosphorus and potassium, in addition to microelements. During the real summer, that is in the months of July and August, the fertilizations must instead be suspended.

As for treatments, for years I have minimized the use of pesticides and I only use copper oxychloride and Neem oil. The first is a fungicide which should be administered by nebulization only in the months in which the plants are not in vegetation (in this period it should therefore be avoided). The second is a natural product, with low environmental impact, against parasites, mites and with a modest fungicidal function. Neem oil can be administered, always by nebulization, even in this period, with the foresight to act only when the sun has gone down or early in the morning, before direct light reaches the plants. Targeted fungicides and insecticides can be used in specific cases, for example in the event of an attack by the cochineal or rot that affects several plants. In these cases it is always important to isolate sick specimens from healthy ones and carry out targeted treatments every two weeks.

Here you will find a detailed article on the main adversities of succulents, with general indications on how to intervene.

Always remember that the best weapon against pests and diseases of succulents is correct cultivation, in particular a spartan cultivation, with lots of light, lots of air, little fertilization and little fertilizing.

To repot or not to repot?

In this case there is no definitive answer: during the summer it is possible to repot. Personally I prefer to avoid – except in cases in which the intervention cannot be deferred as the plant is in evident state of suffering and has probably lost its roots – and to postpone repotting until the end of winter and spring. With new purchases, especially if the plants are in peat, repotting is instead recommended at any time of the year: it is better to stress the plant a little rather than leave it in an unsuitable substrate, running the risk of triggering rot. As always, if you repot and clean or shorten the roots, it is important to leave the flared plant in a shady place for at least ten days before repotting. After repotting, wait another week or two before watering, so as to give the roots time to heal effectively. This precaution is especially important in spring and summer, when the plants are growing and are watered regularly: obviously in winter the problem does not arise, since many succulents and almost all cacti must be kept in dry soil.

Other practices

Otherwise, summer is a relatively quiet time for the cactus and succulent grower. It is sufficient to observe the specimens and understand whether they are slowing down their growth (aestivation) or not and adjust accordingly with watering. Finally, a little maintenance certainly doesn’t hurt: you can cut the now dry floral stems in the case of plants such as Aloe, Echeveria, Crassulaceae, etc., just as it is a good thing to remove the dried flowers of the cacti, which with watering they soak in water and can feed molds and fungi.

Seasonal cures in detail

If you want a complete picture of seasonal care, with everything you need to do in spring, summer, autumn and winter to take care of cacti and succulents in the best possible way, you can consult this summary article.

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Correlated articles

Watering cacti and succulents: when and how
How to repot cacti and succulent plants
Substrates for cacti and succulents
The correct soil: the materials you can use

© The texts, videos, photos and graphic elaborations of the site “Il fiore tra le spine” are original material and are covered by copyright. It’s forbidden to reproduce them in any way.

L'articolo Towards summer: useful tips for taking care of cacti and succulents and avoiding nasty surprises proviene da Il fiore tra le spine.

I’m not particularly fond of crested succulents, but at the same time I’m not entirely indifferent to their charm and every so often some “monstrous” specimen ends up in my greenhouse. Small digression: if you don’t know what a “crested” or “monstrous” plant is, there is an article on the italian version of the website (you can find it here and use the internal translator). Having said that, in the last few weeks I bought a crested Cereus peruvianus monstruosus from a nursery specialized in succulent plants. The plant is in excellent health and well formed, but the substrate, as almost always happens when buying cacti, is excessively peaty, at least for the type of cultivation I’ve been using for years now. I then took the opportunity to describe the repotting operation of this Cereus, so as to be able to speak of “monstrous” plants, of repotting, of simple substrates and within everyone’s reach from the point of view of realization and of good practices to follow when buying new plants.

Here then is the report – accompanied by photos of the individual steps – of this repotting, with some useful considerations, precisely, regarding soils, new purchases and crested cacti. (…)

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L'articolo A repotting… monstrous! How to choose a cactus well and what to do immediately after the purchase proviene da Il fiore tra le spine.

To those wondering to what extent the substrate affects the growth of cacti; for those wondering if natural gypsum (also called agricultural gypsum) can be useful in the formation of robust thorns, this article will certainly be useful. Article which is nothing but the update of a small experiment – one of the many I do with my plants – which I started in July 2020 and which gave surprising results, amazing me first. Yes, because although the test sample is limited (six plants in all) and the results are therefore to be considered indicative and far from absolute, I must confess that I did not expect such a response just over two and a half years after the start of this test. It is known that substrates can literally make the difference in the growth of cacti and that natural gypsum (at least with some species of cacti) is an exceptional element, but it is with direct evidence, with the experimental method that we can really appreciate the impact of the soil in the growth of our succulents.

In this article, therefore, we go into the details of the experiment and see, after more than two and a half years, the results I obtained, which in my opinion are remarkable. (…)

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L'articolo Identical cacti in different substrates: extraordinary results of my test and the surprise of natural gypsum proviene da Il fiore tra le spine.

In this article we see how to make a proper substrate for use with any genre of cactus and, with appropriate adjustments, with succulents, in general. We will make it, and this is the point of this article, with materials that anyone can now easily find in any place (…).

Introduction

One characteristic that any substrate for cacti and succulent plants, in general, must have is the ability to drain water and dry quickly. It is the starting point, the end to which we must strive if we want to make good potting soil for succulent botanical families. The materials we can use are virtually limitless and can also vary according to the type of cultivation we want to pursue. Spartan cultivation to obtain plants similar to those in the wild, “push” cultivation to have plants that are swollen and “immaculate-looking,” “maintenance” cultivation, that is, with no particular purpose other than to grow the plant properly, etc. The combinations we can make with various materials are virtually endless and, theoretically, we could try to prepare a suitable substrate for each individual species that we intend to grow. Each plant has its own specific needs, and even among cacti, there are the species that want more organic material, others that want exclusively mineral potting soils, others that require lime substrates, and so on.

Of course, this fact opens the door to experimentation, which I recommend to anyone who has the time, desire and curiosity to test various substrates to figure out which is the best formula for this or that kind of plant (obviously in combination with the other growth factors, such as water, exposure, temperatures…).

Here you will find an article related to one of the experiments I have done over the years.

The “common” materials

After this long introduction, going back to the purpose of this article, which is nothing more than to provide basic directions for making proper soil for cacti and succulent plants using only materials readily available in any nursery and building materials retailer. Yes, because while it is true that online we can buy (up to certain quantities, of course), peat, quartzite, gravel, sand, gypsum, pumice, and lapilli of all colours and sizes, as well as potting soils specially made for cacti or succulent plants, it is equally true that good compromises can be made with “common” materials, especially if you don’t want to have too many problems.

Field soil and marl deserve a separate discussion. Field soil means clay, which can be more or less calcareous, more or less sandy, and more or less rich in nutrients. In short, there are endless types, and the best way to know whether or not that field soil, mixed with aggregates such as gravel, pumice, and sand, is suitable for cacti is to experiment with it for at least a couple of years. We can say the same thing for marl, a material exceptional for growing different kinds of cacti (if you are unfamiliar with marl, find a specific article here). Marl is almost impossible to find commercially, and even when you get it, you should be careful because there are various types, and not all of them are good for cacti.

Learn more about using field soil and marl in cactus substrates in this specific article.

The classic mix

A first viable option for those who want to avoid problems, as I have written on several occasions, is the traditional mix of equal parts lapilli, pumice and peat. It is the most popular potting soil for growing cacti and succulents, especially in skilled nurseries. In principle, it gives good results with all cacti, even working very well for leafy succulents (e.g., Crassula, Echeveria, etc.) simply by adding a little peat or earthworm humus, to make the substrate a little richer organically. Pumice and lapilli usually come in sizes between 3 and 7 millimetres, and this type of substrate is easily found online or at skilled nurseries. Unfortunately, it is not yet found commercially in all nurseries or gardens that do not specialise in succulents.

This is the article’s main focus because this substrate can be made without difficulty by retrieving materials from any large nursery or garden store.

First of all, the peat. It is the organic component of the substrate that contains the nutrients needed by plants. Most cacti, in nature, live in organically poor soils, which is why in the correct substrates intended for these plants peat should never be prevalent. Again, peat retains moisture for a long time, while the basis of a valid substrate for succulents, as we have seen, is the ability to drain water and dry quickly. For these reasons potting soils intended for cacti, it’s a good idea not to use peat percentages of more than 40 per cent. With some species, particularly those with “taproots” (e.g., Ariocarpus), the amount of peat will have to be decidedly small: a maximum of 20 per cent of the total. On the contrary, in leafy succulents is correct to provide at least 50 per cent peat because these plants need more organically “rich” potting soils. At the same time require greater amounts of water than cacti (their substrate will therefore have to remain moist a little longer to allow the roots to absorb the necessary water).

Peat can be found in any nursery: in fact, it is the material that makes up all so-called ‘universal potting soils’, i.e. intended for any genre of plants. At the same time, peat is the basis of all other packaged potting soils that we find in gardens: from those for citrus trees to those for ornamental plants, turf, acidophilic plants, and aromatic plants. All these potting soils are composed mainly of peat (there can be different types, but it is always peat) and, as appropriate, small percentages of sand, perlite, or pumice. The only potting soil not to be considered with succulents is orchid-specific potting soil, which contains no peat (or very little of it) and is composed mainly of bark.

The same ready-made potting soils for cacti and succulents are nothing more than peat with a little sand, pumice or perlite. On their own, they are no good, but they can be considered on par with peat or universal potting soil, with the advantage that they will already contain some sand, perlite or pumice.
For the rest, one ready-made potting soil is as good as another: what matters is that it is of good quality and that the peat is fine and not rich in filaments, bark, timbers, and other things. If we want to be precise and have a choice, we use blond sphagnum peat, which is slightly acidic and is fine for most succulents.

As an alternative to peat, since from a sustainability point of view, its consumption on a global level has become excessive in recent years, one can use earthworm humus, which can be found in all nurseries.

The other two elements of the traditional mix are pumice and lapilli. You can find both in well-stocked gardens, with one “flaw”: the size is almost always coarse, around 10 millimetres. There are no problems if you have to re-pot large succulents. But if you have seedlings to be placed in 5 or 7-centimetre pots, there are two alternatives and you have to be patient: you can either sift the material keeping the smaller part, or you can use the hammer (with a greater dose of patience) and break pumice and lapilli into smaller pieces. Of the two materials, in my experience, pumice is best, simply because it dries faster. With these three elements (universal potting soil, pumice, lapilli), we can already make a perfect substrate that is very popular in growing cacti and succulents. Mix well one part peat (as a unit of measurement, you can use the scoop) with one part pumice and one part lapilli, and the substrate is ready. If it is intended for leafy succulents, add a couple of scoops of peat to the final mix; if you intend to use it for “mangy,” very moisture-sensitive cacti, reduce the amount of peat by half.

The ‘simple’ mix

A valid alternative to the classic pumice/lapillus/peat mix, which can also be found for sale online or in large bags at some nurseries specialising in succulents, is the potting soil that I have prepared in the video published below. It is an even simpler but perfect substrate for almost all cacti and succulents, which I use when I finished my specific mixtures. Again, the starting point is peat. If the universal potting soil is of good quality, there will be no need to sieve it because it will not have any residual bark, coconut fibre, wood and other ‘impurities’. Good quality universal potting soil, it bears repeating, is usually peat of two or three types already sieved fine (and even this is fine because we will be adding the ‘coarse’ part to the compost), and added with a little pumice or, more often, perlite.

To one part peat, we add one part pumice and half a part fine sand, and the substrate is ready. As I have written before, the pumice we find in gardens is usually coarse-grained but can be sieved or crushed if necessary. Sand, on the other hand, is easily found at building material dealers. Caution: it must be river sand, preferably silica sand. Avoid sea sand. As I pointed out, in this substrate to one part peat and one part pumice I add only half a part sand because fine sand is only very useful in small quantities. If we were to make potting soil with only fine material (sand, pure peat or pumice powder, for example), we would create a potential succulent ‘killer’. In fact, after a few waterings, the substrate would compact and remain constantly moist, causing asphyxiation and root rot. Therefore, it is essential to have both a fine part (useful for rooting) and a coarse part in the substrate, which can make the soil ‘loose’ and increase its drainage capacity.

As I explain in the video, we can make small changes to this mixture if necessary so that it is also perfect in specific cases. For example, if we have to re-pot leafy succulents or hardy plants such as Echinopsis or epiphytic cacti such as Epiphyllum or Schlumbergera we can increase the amount of peat a little (add a couple of shovelfuls at the end and mix everything well). On the contrary, if we are dealing with delicate, slow-growing and particularly sensitive to stagnation plants such as Ariocarpus, Pelecyphora, Aztekium, Copiapoa and others, we can halve the amount of peat and add gravel or quartzite to the substrate.

The latter are also readily available materials in any city. Gravel (with a grain size of between 3 and 5 millimetres) can be found at building material dealers, often mixed with sand. In these cases, with a bit of patience and a fine-mesh sieve, you will be able to separate the sand from the gravel and thus be able to use them in separate dosages. On the other hand, quartzite can be found in aquarium shops or pet shops. There are countless types of quartzite: it can be bought in various sizes and colours. Just be sure it is not “treated” or in any way coloured material.

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L'articolo A good cactus potting soil with materials readily available in any nursery? Here is how to do it proviene da Il fiore tra le spine.

Let’s see in this article how to correctly choose the plants for our compositions (…)

Avoiding difficult cohabitation

First of all, compositions with different plant families should be avoided: succulents together with tropical plants such as orchids, or succulents together with carnivorous plants, just to mention a couple of examples, are combinations to be discarded without any doubt. The needs of plants belonging to different families can be completely irreconcilable, and by making an arrangement we are forcing some plants into a coexistence (in a pot, bowl or any container) that in nature would never occur and that in the long run is bound to fail. So why should we throw away time, labor, materials and plants just to enjoy for a few days or a few weeks a combination that only works from the point of view of our aesthetic standards?

Being coherent with the philosophy of this site, let’s then talk about arrangements made only with succulent plants (vulgarly known as “fat plants”). Again, however, it’s important to consider that the world of succulents is very broad and includes dozens of families, hundreds of genera and thousands of species, each with its own specific needs. In some cases the needs are compatible, in others less so, and in others not at all. A first important distinction to do is between cactaceae and noncactaceous succulents. As is usually said, while it’s true that all cacti are succulent plants, it’s true at the same time that not all succulent plants are cacti. And the difference between a cactus and any other succulent (e.g., a Lithops, a Crassula, an Euphorbia, etc.) can be quite remarkable not so much in shape and appearance as in growing requirements. So much so that the coexistence of these plants in a single pot may prove impossible or at any rate short-lived.

For those who want to approach the subject and begin to understand the difference between a cactacea and any other succulent plant, I recommend reading this introductory article of mine on classification. Don’t be frightened by the topic: actually learning to distinguish the various succulent plant families is less difficult than it may seem!

Choosing plants

The first criterion in identifying plants for composition is based, of course, on the personal taste. Anyway, it may be useful to keep in mind a few simple pointers. For example, it may be interesting, for the purposes of the final result, to choose plants with different bearing, so as to achieve a “wavy” composition, with tree-like succulents and others with low or prostrate habit. But even this, all things considered, is related to the aesthetic taste, and compositions made with several specimens of a single succulent genus can also prove pleasing. One example? The classic bowls filled with Lithops, the so-called “stone plants”: they are beautiful because of their similar shape but infinite color shades. On the other hand, the “objective” factors to regard when placing several plants in one container are the following: soil, frequency of watering, minimum tolerated temperatures, and exposure. Assuming that we are talking here about succulent plants, the combinations can be many, as long as we choose plants that have similar needs in terms of soil, watering, temperature and exposure. It is enough to know a minimum of the characteristics of the various succulent families to select which plants we can combine and which are better not to keep in one container. An example: I do not recommend putting cacti with leafy succulents (e.g., Crassula, Echeveria, Hoya, etc.) in the same composition. The reason is very simple: cacti can live for months without water, while most leafy succulents if they stay dry for a few weeks start to perish. The water requirements of these families are very different, and while coexistence is still possible, my opinion is that it’s not the case to complicate life and, above all, make the plants suffer or otherwise grow in unsuitable conditions.

Related to the frequency of watering is the issue regarding the potting soil: a cactacea, as well as a Lithops or several species of Euphorbia with a compact bearing, grows best in poor substrates, with a lot of aggregates and little organic material, while leafy succulents need significantly higher percentages of organic matter (at least 50 percent). It’s clear that in a container shared by all plants, we are not able to use different potting soils according to individual needs, but we have to to stick to the criterion of “one size fits all,” that is, the product that will satisfy all needs.

Temperatures are also important, unless we decide to keep the composition indoors all year round (but I’ll never recommend it for succulent plants). There are succulents, such as cacti, that in dry potting soil can tolerate temperatures well below freezing without problems; others that cannot go below 12-14 degrees (e.g., Adenium, several species of Euphorbia, and all succulents native to Madagascar).

Similar discussion for exposure: some succulents want a lot of light, if not direct sun, while others do not tolerate excessive levels of sunlight and grow well in half shade (many Euphorbia and the Haworthia, to name a couple of cases). Clearly, if we put several plants in one container, it’s appropriate to choose specimens with similar light requirements, so that we do not have problems or imbalances in growth, with healthy plants and others sunburned or etiolated and suffering from too much or too little sun.

Choosing the container

This is a purely aesthetic question related to personal taste, as much for colour as for shape (square pot or rectangular box, round pot, tall pot, low pot, bowl, etc.). Just a couple of considerations: the container chosen for compositions must be adequate for the number of plants we intend to place and must be deep enough. In other words, the container must be able to comfortably accommodate the root bread of the plants that you place there. This may seem like an obvious clarification, but taking into account that very often for compositions we use those beautiful enameled pots for bonsai, I think it’s necessary to remember that the less space we give the roots to be able to develop, the more we limit the growth of the plants (and maybe this is exactly what we want: to make a composition in which the plants are always “under control,” that is, of limited size…). When choosing a container, the only imperative is: make sure it has drainage hole(s)! Water stagnation is detrimental to all types of plants, except aquatic plants…. Regarding the material, anything can be ok, and each element, terracotta, plastic, aluminum, wood, can be valid or not.

For a more in-depth look at the topic, I recommend reading this specific article.

How to proceed

Once the plants and container have been chosen, the first thing to do is to try arranging the succulents in the new pot or bowl without removing them from the plastic pots to get an idea of how to make the composition. For this purpose, it may be useful to spread a layer of one or two centimeters of expanded clay on the bottom of the new pot: this way we can easily move the plants around and try several combinations to get arrangement we like best. Of course, we can also decide to include other elements in the composition, such as rocks or pebbles of various sizes. Again, the “trial run” with the plants still in their individual pots is most useful to get clear ideas before proceeding definitively.

Once we have found the arrangement we prefer, it can be useful to take a photo with the cell phone (which is always handy), so that any doubts can be cleared up immediately when we go to repot the plants by removing them from their individual pots to arrange them in the new container. If the plants are in the correct substrate, i.e., peat and aggregates, it’s enough to take them out of the pot, check that there are no pests in the root ball, and place them in the new container, at the bottom of which we have placed some potting soil. If, on the other hand, the plants we need to repot are in pure peat (as is often the case when buying them from non-specialized nurseries), it’s a good idea to remove some of the potting soil and untangle the roots as much as possible. With cacti this procedure should be done very firmly, removing all the peat with the help of a brush and, in case the soil loaf is very dry, with a stream of water (before repotting, however, it’s necessary to leave the plant with the roots in the air for at least a week).

Once the plants have been placed in the new container, all we have to do is fill it with potting soil, starting from the edges and going all the way to the center, avoiding leaving gaps here and there. This is both to give stability to the plants and to avoid stagnation or “puddles” when we water. When we have filled the pot with the substrate and stabilized the plants, it will be useful to tap the container lightly and several times on the shelf so that the potting soil is evenly distributed. Remember to stand at least an inch and a half below the rim of the pot with the substrate so that there is no spillage of potting soil when we water.

Finally, to complete the composition, if you like the effect, it may be useful to spread a layer of grit on the surface. You can use river gravel or aquarium quartzite (you can find it in every color): this is also a matter of personal taste. Beyond the aesthetic aspect, however, spreading a relatively heavy layer of inert material on the surface is a great way to even out the color of the substrate and to keep the pot tidy, especially when watering. The layer of inert material (it is best to avoid porous materials such as pumice and lightweight materials such as perlite) should be one centimeter thick at most. If we use gravel or quartzite, the water from watering flows quickly between the pebbles and doesn’t form stagnation around the collar. At the same time, the grit layer ensures that in the warmer months the water doesn’t evaporate too quickly, particularly if we have used a very draining potting soil. Another material to avoid for the surface layer of the arrangements is fine sand: it retains moisture around the collar of the plants for a long time, and with “vigorous” watering it leaks everywhere.

Landscaping

Quite different from the concept of “composition” is that of “landscaping“. In this second case, compositions are made with plants, but the ultimate goal is to reproduce as closely as possible the aesthetic appearance of the natural habitat. Take a look at this video and you’ll understand immediately what I mean! Thus, for these compositions there are very precise rules that govern the choice of plants, potting soil, elements that embellish the composition (rocks, branches, shrubs). In short, here the aesthetic criterion is oriented by reality, so much so that in order to create these small “habitat cutaways” one is inspired by Nature, observing in detail photographs of the environment one intends to reproduce and using materials that are compatible if not identical to those found where succulent plants grow wild (marl, chalk, field soil, sand, etc.).

If you want to know everything about the materials with which to make substrates, here you will find a specific article.

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My video

Correlated articles

Six identical cacti in three different soils
How to repot cacti and succulent plants
Substrates for cacti and succulents
Fertilization: how and when

© The texts, videos, photos and graphic elaborations of the site “Il fiore tra le spine” are original material and are covered by copyright. It’s forbidden to reproduce them in any way.

L'articolo Compositions with succulents: how to choose plants and what is important to know proviene da Il fiore tra le spine.