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.

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

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

Net of purely aesthetic and therefore personal choices, let’s see how to choose the right containers for succulents’ cultivation, evaluating the pros and cons of the various shapes and materials with which the pots available on the market are made. (…)

Foreword

Cacti and succulents, in general, are very tolerant and adapt to various methods of cultivation. This is another reason why the choice of the pot is often dictated almost exclusively by aesthetic reasons. Over the years, I have seen cacti grown in enamelled pots, in bonsai pots, or in tin pots, if not in recycled cans, or even in elegant wooden containers. The aesthetic aspect is not up for discussion: it is personal and gives little or nothing to “reason”, that is, the pros and cons of cultivation. In short, in these cases, the pot is chosen because it is liked. This is not the idea of cultivation I’ve had through the years, as those who follow this site know, based on the plant’s wellbeing and on obtaining robust specimens that look as much as possible like those plants in nature. For myself, concerning the use of pot or container, the aesthetic aspect is definitely in the background. I’m not saying that I don’t appreciate a beautiful setting in an aesthetically pleasing vessel (I’ve made more than one myself over the years): I’m just saying that for the vast majority of my plants, the choice of the pot is dictated first and foremost by “functional” reasons and in this area, as we will see later, countless considerations have to be made, pros and cons to be weighed case by case.

Vases, bowls, cassettes: the types

Beyond the compositions, which bring together several plants in a single container – often neglecting that plants have very different cultivation needs – succulent and cacti can be grown in single pots or in large containers, such as bowls or crates, capable of accommodating a variable number of specimens. The pros of the choice of the single vessel are obviously the saving of space, the simplification obtained in the management of a single container (even if heavy) compared to the moving of many little pots and in fact that in single pots, the plants have more space to expand their roots and, consequently, more soil. The cons of this choice, however, are significant. Firstly, some plants will colonize the space faster, spreading their roots at the expense of others, with the result that the latter will grow more slowly and remain smaller. Secondly – and in my opinion, this is the most important consideration – in case of disease, we risk losing all the specimens and not only the one initially affected. Let’s think of a cochineal attack, for example: in plants in close contact, the parasite will soon pass from one specimen to another. Worse still in case of root parasites or fungal diseases, in particular, those originating from bacteria present in the soil: in these cases, the affected plant will quickly share the problem with all the others grown in the same container, and we risk losing not one but all the plants grown together.

Another risk for that plants grown in single containers is related to watering. If we water at the wrong time or exceed it (especially if the soil is not correct), we’ll have water stagnation that will affect all. Because of this, I have been growing my plants in single pots, limiting the cultivation of multiple specimens in single boxes or bowls only to some succulents such as Lithops, Crassula, Sempervivum and Echeveria, or particularly strong cacti such as Echinopsis. I also grow my seedlings in single containers for obvious reasons: I place several seeds in the same vessel, and for one or two years after germination, the seedlings remain in that same container. When I have to replant the seedlings, I consider the size of the single specimen. I put plants of two or three centimetres in single pots, while smaller ones will share boxes, seed pots or Styrofoam containers, well-spaced between them to allow the correct root development. In some cases, it has happened to me to lose some single specimens of my sowings because of rottenness, but fortunately, I have never had collective deaths, not even in all those cases in which I have limited myself to remove the rotten specimen without removing the others grown in the same container.

Plastic, brick, aluminium: the materials

On paper, we could say that by now, we are spoilt for choice, as we can easily find pots in plastic, terracotta, aluminium, wood, stoneware, glass, glazed terracotta and other materials. If time ago terracotta was considered the best, today the possibilities are really endless, also considering… the creativity, which can lead to making vases with recycled objects, such as milk, cans, containers of various shapes and sizes…

 Plastic  – While it is true that every material has its merits and demerits, as far as I am concerned, plastic and terracotta remain the two most viable alternatives. Having thousands of plants over the years, I have definitely switched to plastic (although from an environmental point of view, it is not the best…). The reasons that can lead to prefer plastic pots, which are easy to wash and recycle, are many: first of all, the weight, which is decidedly low compared to one of the terracotta pots. This may seem a minor consideration, but when you have many plants to move twice a year from the greenhouse to the outside (and vice versa), your back will tell you that there is no match between plastic and terracotta.

Another characteristic of plastic is that it does not allow any transpiration from the inside to the outside. In other words, the walls of plastic pots, differently from the terracotta pots, do not allow any air exchange between the substrate and the outside. This cause that water to take longer to evaporate, as it can only evaporate up to the surface. So we will have to learn to calibrate the watering according to the pot size (a 2-inch pot contains very little soil compared to a 10-inch pot, for example) and, above all, according to the substrate composition. Of course, the bulk of the work will be done by the plant itself (in addition to the drainage holes in the bottom, which are necessary for any pot), which absorbs water from the substrate, contributing significantly to the substrate drying quickly. And this brings us to the advantage of plastic over terracotta: by retaining moisture longer with plastic pots, we can water at longer intervals. When you have many plants, this is a “detail” that loses the connotation of “detail” to gain value.

 Terracotta  – Terracotta pots are undoubtedly more environmentally friendly, more pleasing and natural to the eye and retain (at least in my eyes) an undeniable retro charm. It’s reasonable to opt for terracotta if you have a few plants, and you don’t need to move them several times during the year. However, you have to consider that terracotta allows transpiration from the pot’s inside to the outside, with the consequence that the soil will dry more quickly. While this at first glance may seem like an advantage, in the warmer months, the substrate if very draining, and it will dry out so fast that close watering will be necessary (in summer, even every other day). As long as you have only a few plants, this is not a problem, but when we start to get the hang of it, and the specimens exceed a hundred, watering them all every other day becomes almost another day job: try it!

The third disadvantage of using plastic is generally discovered during the first repotting, especially when you do it after some years. Thanks to the porosity of terracotta, in fact, the roots of the plants, once the colonization of the soil is over, literally cling to the inner edges, so they can take advantage of the humidity that permeates the pots themselves. Over time, the capillary roots cover the pot’s inner rim, forming a sort of “felt” that glues the plant to the vase. When repotting, nine times out of ten, after sweating (and probably swearing) for an interminable amount of time, you will find that the only way to get the plant out of the pot is to take a hammer and crumble the terracotta. At that point, you’ll have more tears to shed: some for the vase itself, which you’ll no longer be able to use, and others for the work ahead of you to break up the loaf of soil and free the felted roots, compact and tangled like the plot of a psychological thriller.

With plastic pots, to flare the plant, most of the time is sufficient to turn the pot upside down, or, in case of large or particularly thorny plants, wrap the plant with a cloth and pull it out of the pot. The only difficulty, when repotting succulents in plastic pots, I found when I let several years pass since the previous repotting: in those cases, the plant had fully colonized the soil, deforming the vase under the pressure of the roots and making it almost impossible to extract, to the point that I could only cut it with a cutter.
Terracotta pots, as plastic pots, are also easily recycled and can be washed, although it takes longer due to the material porosity.

 Aluminium, glass, wood  – With other non-transpiring materials, such as glass and aluminium, the same considerations listed for plastic and related to non-transpiration of soil are valid. However, we have to add the defect that characterizes terracotta, the pot’s weight (at least if we have vases with hard size). Since aluminium and glass containers are generally made for purposes other than plant cultivation, or at best are used as pot covers, it is essential to make sure that drainage holes are present at the bottom: never use pots closed at the bottom (and this applies not only to succulents but to any plant). Wooden pots and containers can be very aesthetically pleasing, but unless they are covered with a plastic sheet inside or treated with special paints, they are destined to become impregnated with water and, over time, to deteriorate and rot, especially in case of outdoor or greenhouse cultivation, with a sprinkling of water.

 Enameled pots for bonsai  – Evergreen pots for bonsai have always been very appreciated and used by cacti and succulents growers. From an aesthetic point of view, they can be real works of art, but from a functional one, suitable for growing succulents only in some cases. This is mainly due to their shape, generally box-shaped and therefore wide and low, so not very compatible with the expansion of the roots in-depth and not recommended for plants with taproots, such as Ariocarpus, Lophophora, certain Coryphantha, certain Mammillaria and many other cacti. Moreover, unless the inside is enamelled, it’s better to avoid bonsai pots in the cultivation of succulent plants: if we leave the plant for too many years in the same container, the only way to take it out will be to break the pot. A real shame, considering the aesthetic and economic value of this type of vases.

Round or square, high or low?

Regarding the shape of the pot, there is little to discuss on a functional level: here, it’s more a matter of taste because the plants adapt perfectly to any type of container, be it round or circular. Generally speaking, it can be said that shallow and wide bowls are better suited to accommodate globular or tall cacti, while traditional cone-shaped or cylindrical pots are aesthetically more suitable for columnar succulents.

One factor that can play a significant role in the option when you have many plants is undoubtedly space-saving. In this case, the square pot is the first choice: it has been specially designed to ensure the full use of space by the plant and, with the same size as a round pot, the square pot contains more soil. And that’s not all: if placed side by side, square vases avoid considerable waste of space compared to circular vases, which, even when placed side by side, will not allow to fully exploit benches or shelves, leaving triangles of empty space between one edge and the other. If with few plants, this consideration can have a relative weight, with hundreds or thousands of specimens, the choice becomes almost compulsory, unless you have a considerable number of huge greenhouses. It is no coincidence that square pots are the ones most used by collectors and specialized nurserymen. Whether you opt for the square pot or the round one, there are two elements to consider when repotting the plant. The first one is the steam size, the second one is the size of the root system. In both cases, there must be a proportion between the plant and the container. As for the stem, the choice is simple and entrusted to aesthetic canons, keeping in mind that it is appropriate that the pot can easily contain the body of the plant and, possibly, the thorns (unless these are exceptionally long, as in the case of some Lobivia or some Ferocactus). As a general rule, it’s recommended there can be two to four or five centimetres between the stem and the pot’s edge.

However, concerning the root system, the evaluation requires some experience and a surplus of observation when we’ll have flared the plant. First of all, if we are dealing with a cactus with a taproot (i.e. a “carrot” root, as in Ariocarpus), it’s necessary to use high pots, where the taproot can be comfortably accommodated, and the rootlets can develop in-depth rather than width. In these cases, we will avoid bowls and choose cylindrical or square pots instead (in the last years, you can find high pots for plants like Ariocarpus, Lophophora, etc.). If, on the other hand, the root system is not taprooted, we will have to evaluate based on the specimen to be repotted: if the roots are short and thick or if we see that they tend to develop horizontally (this is the case of Echinocactus and many Ferocactus, for example), we can use low and wide bowls or square pots that are not too deep (with the same length of the side, there are high square pots and low and squat square pots). 

One thing, based on my experience, I can affirm: cacti and succulents, contrary to what has been believed for years (and contrary to what too many enthusiasts still believe), do not fear large spaces in which to grow. Miniature pots are an imposition and only limit the growth of the plant. On the contrary, if the soil is balanced and draining, ample and deep pots favour the correct plant’s development of the plant without exposing it to the risk of water stagnation that can trigger rottenness.

It is a different matter if the plant is suffering and the root system is compromised or absent because, in these cases, the choice will fall on low pots and bowls, which we will fill with pumice for helping the plant emit new roots. Large pots can be inadequate if the roots are missing or suffering, because they contain an excessive quantity of soil which not absorb the watering and will remain too long in a wet substrate, if not soggy. So initially, it’s better to use pots and bowls that are not bigger than the ones of the stem, postponing to a second time – at least a couple of years later when we are sure the plant will be healthy again – the repotting in a container suitable for the size of the specimen and for the new root system.

Cactus without roots: how to intervene to save the plant and make it healthy again.

Colours and particularities of pots

From a functional point of view, the importance of the pot’s colour is not so relevant. Some say that black pots can be dangerous because, by attracting and keeping more sun rays, they could favour the substrate overheat and causing the roots to suffer. Theoretically, the argument is not out of place, but for over twenty-five years, I have been using black pots (the classic square pots for growing), and I have never had problems due to overheating of the roots, even in plants that I keep outside the greenhouse, exposed to direct sunlight. In short, I have never experienced any difference from the plants I grow in terracotta-coloured plastic pots, even when, in the middle of summer and after hours of direct sun, they are hot.

I know growers who have the patience to cover the outside of their pots with white tape, just as I know a brilliant grower, David Rubbo, who has the patience to “insulate” many of his pots. He cuts out some polystyrene’s sheets less than a centimetre thick and puts them in square pots inside which he then places the vases in which he has set his plants, thus creating a sort of internal insulation able to lower the incidence of sunlight on the walls of the pot.

Among the peculiarities of the pots currently on the market, it is worth mentioning the anti-spiralization grooves. These are small canals that run along the edges of square vases so that the roots avoid, over time, to turn around the inner walls of the vase, creating tangles that are difficult to untangle when repotting. Frankly, I have never had the chance to experience its usefulness, and when, during repotting, I have to deal with tangled roots, I arm myself with patience and try to free them as much as possible. Apart from the colour, the shape or the anti-spiralization channels, only one thing must never be missing in pots: the drainage hole or holes. Essential for all plants, they are even more so for succulent plants, which do not tolerate water stagnation or excessive humidity. In old terracotta pots, there is always a single drainage hole at the bottom. It’s wide enough to avoid excessive spills of soil, it can be covered with a stone or with a shard of another pot, and it is more than enough for the purpose.

In plastic pots, especially in the square ones, there are usually more slits on the bottom to allow excess water to drain without the potting soil leaking out during repotting when it is dry and not yet settled. On the market, finally, you can also find pots with a semi-open bottom, that is, with a simple radius: in this way, the outflow of excess water is maximum, but it will be necessary, during repotting, to put coarse material on the bottom (lapillus or expanded clay) to prevent the soil from leaking out immediately.

How to choose the pot: the criteria

In the light of the elements just described, choosing the right pot wherever to place a cactus or a succulent plant might seem a difficult task. Actually, all you need is a little experience and knowledge of your cultivation method and of the conditions that you will be able to ensure to your plants: for example, air, full light, minimum temperatures, frequency of watering and fertilizing, type of substrate. The rest is just a compromise between one’s aesthetic taste and the functional aspect. It’s essential to respect the plant’s root system structure and ensure sufficient space for the specimen’s development and growth. You don’t need “bathtubs”, but you should avoid the tiny pots (under 5 centimetres) in which we almost always find succulents in non-specialized gardens. The correct potting soil and the right cultivation will do the rest.

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Correlated articles

Six identical cacti in three different soils
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 Plastic, terracotta, square or round? Here’s how to choose pots for cacti and succulents proviene da Il fiore tra le spine.

Speaking of cactus sowings, a classic question, and one not infrequently asked with a fair amount of (unnecessary) apprehension, is: after how long should seedlings be repotted? In other words, when do the young seedlings need to be repotted and perhaps divided into individual pots? Again, as with many other “cactophilies matters”, the answer depends on various cultivation factors. Based on experience, however, it is possible to give general indications useful to those who experiment with sowing for the first time.

Let’s see in detail, in this article, everything we need to know about this fundamental step for the proper growth of plants from our sowing. (…)

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L'articolo When to pricking out cactus seedlings, how to do it correctly, and what potting soil to use proviene da Il fiore tra le spine.

Let’s see how to proceed and all there is to know about repotting,
especially the most challenging ones due to the plant’s size and the thorns on the stem. (…)

There is repotting and repotting…

Obviously, repotting is easy for Cactaceae or succulent plants with little or no thorns, such as most Astrophytum, but also Matucana madisoniorum, many Gymnocalycium, some Turbinicarpus, Frailea, as well as plants with papery thorns (Tephrocactus articulatus v. papyracanthus) or silky-thorns, such as some Mammillaria and Rebutia, or succulents such as Echeveria, Crassula, Lithops, etc… In the same way, everything is easier if you are dealing with young specimens and therefore of small dimensions. In these cases, even the most prickly plants can be repotted without problems since the plant itself weighs very little, and it is not necessary to exert pressure or special efforts to remove it from the pot and place it in a new container.

Challenging repotting

For more demanding subjects, such as a E. grusonii from 20 centimetres in diameter upwards, it is necessary to be patient and take some precautions. Many people use gardening gloves: I avoid them because they deprive the hands of the slightest sensitivity, and it is easy to break thorns or damage the plant if you don’t have the right… touch. When starting a repot of this kind, i.e. large plants covered in thorns, the first thing to do is to have the necessary supplies on hand, i.e. the new pot and the potting soil. At that point, it will be enough to wrap the plant in an old towel or fix some polystyrene blocks to the thorns to protect them and avoid breaking them or getting pricked. When the plant is “packed”, it can be lifted and tilted to the side so that the old pot can be removed.

If the plant has been in the old container for many years and the soil is compact, the operation could be more complex. In the case of a plastic pot, you will have to vigorously beat the walls of the container with the palm of your hands (in many cases, you need your fist!) to try to make the soil loaf come off and slide the plant out. If you have used a terracotta pot and the plant has not been repotted for years, you may need to arm yourself with a hammer to break the old container. With terracotta pots (porous material, unlike plastic, which is perfectly smooth), the roots stick to the inner walls because they can absorb water, and in many cases, during the repotting, there’s no alternative to breaking the old container.

In this regard, it must be said that even the choice of the correct pot is fundamental, and on every type of container, there are pros and cons. Terracotta or plastic? Round pots or square pots? Small vases or wide bowls? Many individual vases or more plants in one container? All of these questions are answered, as well as fully explored, in this article.

On repotting, in general, you can find everything at this other link.

Once the plant has been freed from the old pot, it is advisable to check the state of the roots, verify that there are no parasites such as cochineal and remove as much as possible the old soil. If the plant is already in suitable potting soil, it will be enough to shake it and free the roots a bit; if the old substrate is rich in peat or too much used, it’s better to get busy (maybe even with the help of a brush) to remove it and free the root system.

If some roots are too long, and if they’re not primary roots (thick and fleshy), you can shorten them with scissors or gardening nippers: just a clean-cut, the plant has no problems, stimulated to produce new capillaries.

New pot, new soil

Before repotting, many people recommend leaving the plant’s roots in the air for a few days to allow them to heal the wounds suffered during cleaning. Frankly, I see the reason only if some primary ones are broken, or the root system has been thoroughly cleaned, for example, because the roots were dry or rotten. In other cases, I repot immediately after cleaning, with the only care to use dry soil and not to water for at least ten days after repotting.

Whichever choice you made (wait a few days or repot immediately), all you need to do is to put a little potting soil in the new pot, place the plant on it, being sure the collar is at the right height related to the edge of the container and fill it all around the stem with the new substrate. Some growers recommend putting expanded clay, pumice, or coarse-grained lapilli in the bottom of the pot to promote drainage. I do this only when I use very profound vases compared to the size of the root system or when the roots are few, dry or too short: in all other cases, I see no reason to deprive the plant of soil if it’s already draining and rightly formulated.

Here I have written about the various types of substrate I use.

With small plants, easy to handle, it is better still to hold the plant with one hand, place it at the right height related to the edge of the pot, leaving the roots in mid-air, and fill the pot with potting soil with the help of a shovel. At the end of this operation, it is a good idea to lightly tap the edges of the new container with your hands, then lift and drop the pot several times on the table to let the potting soil settle and not leave empty areas inside the container.

A little trick

More than strongly thorny plants – Ferocactus, for example, can be easily handled by lifting them by the old thorns, as they are so strong – in my opinion, the real problem is plants with fragile or hooked thorns. In the first case, you need a lot of attention and a good dose of experience (and patience) to avoid breaking the thorns; in the second case, you need a lot of attention because the hooked thorns (as in the genus Ancistrocactus) will inevitably get stuck to the skin with the risk of making it difficult to clean or move the plant while filling the new pot with soil. A trick with this type of plant is to flush and clean the plant, place two sticks (or two brushes that are not too large) on either side of the new pot, place the plant between the two sticks, holding it by the spines and letting the roots fall free into it. When the plant rests on the two supports, we will have our hands free to fill the pot with soil, and when we arrive at the right level, we just have to take out the sticks, hold the plant by the thorns and finish the job by putting the substrate around the collar.

Beware of glochids!

The really tricky plants are those of the Opuntia genus. Most of them have very short and thin thorns, called glochids, that can enter the skin and firmly hook thanks to the hooked tip. Glochids don’t hurt, but they are very annoying, irritating and almost impossible to remove immediately. For repotting these plants is the only time I use gloves unless the Opuntia “blades” are large and the glochids are widely spaced, in which case you can handle the plant without getting glochids on your fingers.

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Correlated articles

Six identical cacti in three different soils
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 Repotting cacti: a few tips on how best to do it without… donating blood! proviene da Il fiore tra le spine.

Some growers repot every year, while some others repot when required – i.e. when a plant shows signs of suffering or when the pot has become too small related to the stem. There can be many reasons for repotting (or racking, as someone says alternatively) a cactus or a succulent plant, and every grower has his own rules. As for me, I don’t have “fixed deadlines”: I evaluate plant by plant trying to understand if new soil and more space are needed. I repot my succulents when I see that the vase is now too small, when I believe that the soil has exploited or when I want to grow specific specimens more quickly. While it is true that many plants live quietly in the same container for five or six years (in many cases even longer!), it’s also true that frequent repottings (once a year or every two years) help to speed up the growth of cacti, particularly young plants and genera that over time take on considerable sizes, such as Echinocactus and Ferocactus. I repot, also, when I notice that a plant has blocked for a long time and it doesn’t grow or produce new thorns. It can be the spy that something, at the root level, is going wrong. A plant that doesn’t grow or doesn’t swell despite watering, or, again, a plant that loses its colour (showing, for example, a lack of magnesium that not even fertilization can solve) can be saved by a repotting, with the cleaning of roots and the supply of new soil.

So let’s see in this article in which period it is better to repot cactus and succulent plants, which pots to choose (square, round, terracotta or plastic), how to check the roots and how to proceed in practice. (…)

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L'articolo How to repot cactus and succulent plants: in which period, how to proceed, which tricks to use proviene da Il fiore tra le spine.