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.

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.

Who hasn’t happened at least once to observe in some office, apartment or even non-specialized nurseries (or garden) those cone-shaped cacti with thin spines and pale green stem? Cacti with a rounded base and an elongated apex, tapered to the point of giving the plant an almost pyramidal shape. The novice grower may think that is the normal bearing of the plant, but the grower with some experience – or even just a critical mind – usually is horrified at such plants. If anything, he or she may be saddened, because he or she knows full well that that is not the normal bearing of the cacti at all, but simply the outcome of what is technically called “etiolation” or, commonly, “spinning.” By the way, the photos above and those accompanying this article are of plants in a nursery and not mine, I want to make that clear right away!

Why does this fate happen to some cacti? How to avoid cactus etiolation and how to distinguish it from normal growth or from growth that is simply dissimilar to normal? Is it possible to remedy the damage caused by spinning on a cactus? We answer these questions in the following article. (…)

Let us first clarify that cactus etiolation is a phenomenon that affects not only cacti, but all botanical families. If anything, the problem with cacti is that it is generally an arrestable but, unfortunately, irreversible process. If in leafy plants, shrubs and trees in general it’s indeed possible to remedy by perhaps even drastically pruning the “spindly” branches, in cacti there is little that can be done to restore the plant to its original state. The reason is obvious: cacti develop through single or at most suckered and only rarely branched bodies (think of some candelabra-like cereus), but on the whole the shape of the stem is the shape of the plant, is its appearance. It is one and the same in short. That’s why effectively remedying etiolation is very difficult: you can bring the plant back to an acceptable condition, but if the phenomenon has affected drastically, returning to the original form will be impossible. I will discuss this in more detail later.

Definition of etiolation in cacti and succulent plants

Let us first see what exactly is meant by the term “etiolation” from a botanical point of view. A brief but at the same time comprehensive answer can be found in the easy-to-read booklet, “Conoscere e coltivare le piante succulente” (“Knowing and Growing Succulent Plants“) published by the Italian Succulent Plant Lovers Association (Rome, November 30, 2005), which defines this phenomenon as follows: “Physiological process that occurs in plants when they are in a condition of insufficient light, consisting in an elongation and thinning of stems and branches that thus increase the surface area suitable for photosynthesis“. The first basic clue is that this is a physiological process, thus in some ways “natural.” Natural in a relative sense, since it’s a plant response to suboptimal (in not wrong) growing conditions. In fact, the definition goes on saying that etiolation occurs when plants are in “an insufficient light condition“. So the real cause of this phenomenon is the lack of light. Plants “spin,” as it is commonly said, not when they are in an inadequate substrate or when they are watered too frequently or infrequently or when they are over – or under- fertilized. Plants go into etiolation when they do not get enough light.

However, this concept is also relative and should be commensurate with the needs of the plant. It’s well known that there are plants that can survive only with limited exposure, filtered by other plants. Think of orchids, which do not tolerate direct sun because they are plants native to tropical or subtropical areas and thrive leaning against the branches of trees and shrubs whose foliage shields them from direct sunlight. There are plants that grow perfectly well in half-shade, that is, with bright light for only a few hours, and plants that grow well only when invested with maximum sunlight throughout the day. And this is the case with most cacti, which thrive in semi-desert areas, often in areas where there is little or almost no vegetation. At most, some cacti receive shelter from rocks or shrubs or, in the case of seedlings, from the shade cast by the mother plant. Even in these cases, however, the light they can benefit from is intense and lasts from dawn to dusk. Of course, there are also many cacti that do not tolerate direct sun and grow only under the shelter of boulders and leafy plants, as in the case of the Epiphyllums that live in rainforests and in the case of the “Christmas Cactus” (Schlumbergera) .

Having clarified this first fundamental aspect, the second part of the description helps us understand what the effects of etiolation are and why they occur. Etiolation involves an “elongation and thinning of stems and branches that thereby increase the surface area suitable for photosynthesis“. In other words, plants go in search of light, just as we would go to grasp a distant object: we stretch, we make an effort. The difference is that human beings have a limit and can stretch only within precise physical boundaries (except moving through space simply by walking!), then returning to their original posture once the effort is made. Plants do not have this limit and can elongate far beyond their original status, but they pay a very steep price, which is precisely etiolation, an irreversible process involving the permanent deformation of the plant itself. Branches or stems grow out of all proportion – desperate for the light they hope to find beyond the area of shade in which they find themselves – and once the effort is made they remain deformed, elongated, thinned, with the result that the plant loses its compact and orderly appearance. In other words, it loses its natural look.

Etiolation in cacti, how it occurs

Calming the above definition to the world of cacti, we can add that etiolation is always accompanied by discoloration of the stem, which turns from dark green or bright green to light green. In leafy plants this phenomenon affects the leaves themselves, which turn yellow. Whether stems or leaves, discoloration is always due to the deficiency of chlorophyll, which is produced, as everyone knows, by photosynthesis, that is, with the help of sunlight. In very severe cases, as in many of those you see in the photos accompanying this article, the shape of the stem can alter to the point where a globular bearing cactus (e.g., Echinocactus grusonii) takes on a columnar habit with the apex rising in height while shrinking more and more. For those who are not familiar with cacti, the result may not raise particular questions (although from the point of view of aesthetics there would still be quite a lot to say), but those who have the slightest familiarity with cacti cannot help but be horrified at such compromised specimens. In cacti, moreover, etiolation greatly affects the formation of new spines, which grow much thinner in the “spun” part than they should. Indeed, in cases of severe etiolation the spines are almost insubstantial and sparser than normal.

Etiolation or abnormal growth of the plant?

In severe cases, etiolation of cacti is very easy to recognize. Unless you have no knowledge of this botanical family, it will immediately appear abnormal if the plant has a spun, discolored, thornless apex. If you see it in a nursery, forget about it: it would be a wrong purchase since there is no way back, from an aesthetic point of view. The principle of cactus etiolation, on the other hand, may not appear so obvious. At least not to the experienced grower. We take a good look at the plants, and if we have doubts about their shape, we look online for photos of those same plants in habitat. This will be enough to give us an idea of the correct habit that that plant should have: globular, columnar, branched, tufted, etc. Unmistakable clues to a principle of etiolation are discoloration of the stem apex, which may appear pale green, and the absence of new spines (or the formation of spines that are significantly thinner than they should be). In these cases the plant is beginning to spin and is telling us that it desperately needs light. Be careful, however: let’s not move it into direct sun right away, because the apex of the plant is delicate, especially if it is beginning to etiolate, and we would only burn it. We move the plant to a brighter place for a few weeks, then, if it is a cactus that wants direct sun, we can move it outdoors.

The novice grower may find it difficult to distinguish between true etiolation, abnormal growth or even regular growth. In fact, it may happen that a cactacea with a globular habit grows in height. This is not always a sign of etiolation. Let’s take a close look at the plant: if the stem has no narrowing in the direction of the apex, if the spines are uniform, if the plant has no bottlenecks or discoloration, this is not etiolation but an abnormal growth. This can be due to several factors: first, we have to consider that over the years many cacti tend to become brevicylindrical from globose. They also do this in habitat and it’s normal: many Ferocactus and Echinocatus have this “habit” as do Euphorbia obesa.

Cactus and succulent plants: a guide to identification and classification.

If, however, we are not dealing with large or aged specimens, then it will be abnormal growth due to other factors. Excluding genetics, which we cannot investigate and intervene on, growing factors are irrigation, fertilization, temperature, and substrate. Overfertilization can easily alter the bearing of any plant, as the use of an unsuitable substrate. Also the exposure, even if not insufficient to the point of causing etiolation, may not be adequate, leading that plant to grow differently than Nature intended. By restoring proper growing conditions, we are unlikely to cause the abnormally grown plant to resume a right look, but if nothing else, we will encourage new and proper growth.

What to do against cactus etiolation

Once we have determined that there’s a principle of etiolation or that our plant has been etiolated for some time, we can take corrective action. Beware, however: as I have written, unfortunately there’s no going back, and the etiolated part will remain forever. If we have a branching succulent plant we can prune off the etiolated branches or pull off the yellowed or elongated leaves, but if the etiolation concerns a cactacea… we have to surrender to the evidence and engage us at least to bring the plant back to proper developmental condition. It’s not rare that with time and new growth the etiolated part will become less noticeable, and the plant will react in a surprising way, taking on a bearing that is indeed abnormal but interesting and aesthetically pleasing. This is what happened to the Echinocactus grusonii that I discuss at the end of this article. In any case, once we identify etiolation or the principle of etiolation in a cactacea, all we can do is try to improve the light conditions by gradually moving it. Never put a plant (etiolated or not) in full sun if that plant is not used to direct light: we only expose it to the risk of severe sunburn. We need to read up on the type of plant (e.g., Cactacea or Euphorbia?), figure out what its light requirements are (direct or filtered sun?) and arrive at the correct exposure in stages. While we re-accustom the plant to the right light intensity, we must reduce watering and suspend fertilization. We also postpone repotting so as to avoid further stress to the plant at this delicate stage.

To find out what the various light requirements of succulents are, you can consult this article, which contains a summary table.

If the plant is healthy and if we can give it the correct amount of light (not only in terms of intensity, but also in terms of hours of sunlight), we are able to stop the etiolation process. At that stage, patience is necessary: the plant resumes growing properly, enlarge the apex, which regains its correct coloring, and forms new spines in line with the old ones, that is, stronger and thicker. In other words, the apex returns to normal, and if we look at the plant from above, we don’t see anything abnormal. If we look at it from the side, we can observe the enlarged base, then the bottleneck in correspondence with the etiolation period, and finally the new growth. The effect, in most cases, is that of an “hourglass”, but if we have nipped the etiolation in the bud, there is a chance that the aesthetic damage becomes less and less visible over time.

Finally, we have to consider an important factor: a “spartan” cultivation, in short, that tries to imitate as much as possible the conditions in which cacti are found in their habitat, can only fortify the plants, slow down the growth rates and, at the same time, prevent etiolation of the stems by contributing to the maintenance of the correct and compact form that these plants have.

Beware of winter: should I bring succulents inside?

For those who grow cacti and succulents correctly, placing them in the proper place during the growing season, winter is he only period at risk of etiolation. Not everyone is fortunate enough to have a greenhouse, and even those who have a garden or a large terrace are forced to shelter cacti and succulents as best they can in winter, particularly in areas of northern Italy. Many resort to the stairwell, others use garages or other cold rooms. Some growers use mountable greenhouses or repair plants with layers of nonwoven fabric. In all these cases, if you stop watering altogether from the end of September and if the plants experience a consistent drop in temperatures, there are no problems. This is because under these conditions succulents stop vegetating and stunt new growth while waiting for spring.

If, on the contrary, succulents do not go into stasis, for example because you continue to water while keeping the plants in a heated place or at least at minimum temperatures of not less than 10 Celsius degrees, the risk of etiolation is real. This happen also because one of the first rules for growing cacti (I mean most of the species) involves avoiding “indoor” cultivation, that is, in an apartment. Even if placed on a south-facing windowsill, cacti will never get enough light and especially not for the amount of hours they need for proper growth. While this is true at any season of the year, it’s more true in winter, when the incidence of sunlight is very low and the hours of light are drastically reduced. If we do not stunt growth, in such low light conditions the plant will only continue to vegetate by etiolating, that is, by going in search of light. It is for this reason (as well as to encourage blooms) that it is essential to overwinter cacti and many succulents in the cold. Beware of exceptions, of course: tropical succulents and some genera of cacti do not tolerate too low a minimum (e.g., Melocactus, Discocactus, Schlumbergera). In these cases we can keep the plants indoors, watering no more than once a month just to contain growth.

If we don’t have an unheated place to shelter the plants, we are forced to take them to the apartment. In these cases, we try to place them in the least heated and most lighted room and still suspend watering so as to push the plants to an abrupt slowdown in growth. Finally, let’s keep in mind an important element: if we stop vegetation altogether by keeping the plants in the cold (for example, with lows around 5 Celsius degrees) and suspending watering, the importance of light is relative and we are able to keep cacti and succulents, in winter, even in dimly lit places without running the risk of etiolation. The ideal solution (I realize that this is not always possible) is not to move the plants, that is, to keep them where we grow them in the growing season, i.e., a balcony, a terrace, a greenhouse, while sheltering them from the cold and rain in the fall and winter months (e.g., with layers of nonwoven fabric or with canopies). In this way the plants will follow natural light cycles, enjoy the right temperatures, and fortify themselves while avoiding the risk of etiolation altogether.

Incidentally: it’s for reasons such as those I have outlined above that very often, in non-generic nurseries, we see cacti and succulents terribly spindled, as in the photos I took in recent days in a nursery and publish in this article. There is a tendency in nurseries to try to keep plants always “bloated” and palatable for sale, watering them year-round and sheltering them with overly dense shade nets (necessary for other, more delicate plant families and perhaps kept on the same benches).

Abnormal reactions to etiolation in cacti

In some cases, following etiolation, cacti may react abnormally when restored to optimal conditions for recovery. This is what happened to the Echinocactus grusonii you see in the photo here. The plant, with its typical globular habit, was given to me four years ago. It was kept for at least a couple of years on an office window sill by the previous owner, in inadequate light conditions. When it was given to me it was in very poor condition: the base was rounded and with spines of correct consistency, but the lack of light had caused the apex to grow tall, taking on the characteristic cone shape of heavily etiolated cacti. The apical part was also pale green and virtually spineless: it had only the hint of a few very thin and sparse spines. In short, a disaster. I took the plant to “save” it and, without repotting it, took it to the greenhouse, in a corner sheltered from direct sun. The Echinocactus stayed in that corner for a whole year, receiving very little watering. In this way I began to accustom the plant to brighter light.

After the first year, when I saw that the apex had begun to regain its proper deep green color, I moved the plant outside to half shade. The cactus received direct light only in the early morning hours and then switched to shade. During the second year, the thorns resumed growing properly, but the plant did something that cacti usually do following a damage to the apex (such as from a bump or some insect bite): it began suckering profusely. The apex became covered with suckers, i.e., new heads with strong, long, golden-yellow spines.

Since the plant suckered, I always kept it outdoors from March through September, watering at most once a month if it was not raining. The result, about four years later, is what you see in the photo. When viewed from above, the plant shows no signs of etiolation and has a very interesting shape, with numerous suckers and beautiful spines. If you look at it from the side you can still see the elongated stem, but with time and the development of suckers I am sure that the damage will almost completely disappear and the Echinocactus will become unique, i.e. heavily suckered and definitely beautiful, harmonious in its new form.

A few photographs of cactus etiolation

Below is a gallery of pictures of heavily etiolated Cactaceae and Euphorbiaceae. The photos were taken at a nursery not specialized in succulent plants. Click on the image to enlarge it.

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Correlated articles

How much light do cactus need? A summary table
How to repot cacti and succulent plants
Substrates for cacti and succulents
The correct soil: the materials you can use
When and how fertilize cactus and succulent plants

© 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 When the cactus “spins”: what is etiolation, how to prevent it and contain the damage proviene da Il fiore tra le spine.

In this article, we see what you need to do this month for keeping cacti and succulents in perfect health, even preparing them for winter diminishing the risk of rot and loss. (…)

In August, for several years now, I suspend watering altogether. In the greenhouse, temperatures easily exceed 40 degrees Celsius, and many cacti slow down or stop growing because of the phenomenon known as “estivation”. Many species keep to flower regularly (e.g. Gymnocalycium, Ferocactus and some Mammillaria), but it doesn’t mean that the growth’s rate has not slowed down. That’s why I prefer to avoid watering all my plants, except the leafy succulents, and let them follow their natural rhythms. This prevents the soil from staying wet for too long when the plant is in dormancy, and it causes root or collar rot.

Watering

The last watering of the summer is usually at the end of July for all my cacti, especially for those with particular growth rates, such as Copiapoa and Neoporteria, for which I stop watering even earlier, in mid-June. At the beginning of September, I start watering all my plants again, thinning them throughout the month and watering them every ten days at the most. The actual cessation of watering usually coincides with the beginning of October to give the soil time to dry out totally and for the cacti to reduce their internal water reserves and start preparing for autumn and winter. This is true for adult plants: for seedlings and one or two-year-old plants, I extend the watering period until mid-October, but water sparingly. I pay particular attention to plants of the genus Ariocarpus, which I water until mid-September at the latest. These plants, which have tap roots, are sensitive to humidity and have considerable water reserves, and I have learned that with the climate of Northern Italy, characterized by very wet and often cold winters, it’s suitable to stop watering earlier. The plants are not affected at all and do not deflate until late in the winter. Moreover, they bloom abundantly from mid-autumn to the first half of December.

Fertilizations

In September, as far as fertilizing is concerned, it’s better to give the last coat with a specific product (here is an article dedicated to fertilizers for cacti and succulents). You can have a first watering at the beginning of September with only water and add fertilizer in low dosage at the second watering, after about ten days. Fertilizing in September is helpful for the plants: it gives them the nutrients they need to get stronger before the winter break and helps the blooms when they resume in the spring. I generally limit myself to single fertilization in September, but it is possible to fertilize a couple of times before the watering stops, as long as low doses are used. Again, the situation is slightly different for seedlings and young plants (one or two years old): for these, I add fertilizer during the last watering in October to “push” them a bit and strengthen their growth.

Treatments

September is also the month of preventive treatments against parasites and diseases. Since the plants start to vegetate again, it is not recommended to use copper-based fungicide (which slows down the growth), which should be sprayed instead in the autumn months and only on warm and windy days. Some spray with copper fungicide throughout the winter, once or twice a month to prevent the proliferation of fungi or “rust”, but for several years I limit myself to a couple of passes in October and a couple of passes in February, just before the recovery. In September, however, it’s advisable to add a broad-spectrum fungicide to the water for watering and spraying the plants a couple of times with an acaricide or Neem oil, a preventive measure against aphids, mealybugs and other pests.

Checks

It’s important to carefully check the plants to identify those suffering and isolate them immediately to prevent them from spending the fall and winter months in contact with healthy plants. In this way, you can preclude the risk they may transmit diseases that can spread with the humidity that usually there’s in autumn.

Repotting

Finally, stop repotting. For several years now, I have avoided repotting (except for plants in severe pain) in September when cacti and succulents are vigorously vegetating again and in October and November. While repotting can generally be done almost any time of the year, I prefer not to “disturb” my plants at this time of year to avoid the stress of repotting in the crucial phase of preparation for autumn and winter. On the other hand, repotting can be done without problems when the plants are in stasis, i.e. in late winter or, better yet, towards the end of winter, just before vegetative recovery.

All about the repotting in this section of the site.

Also, by repotting plants before the end of winter, we will be sure that several weeks will pass between repotting and the first watering, thus giving any roots that may have been damaged or cut during repotting plenty of time to heal before wetting the soil.

Plants in outdoor

The plants I keep outside the greenhouse during the growing season finally stay in place, exposed to direct sun and weather, until mid-October if the early fall is not particularly rainy. At that point, I move everything back inside the greenhouse, which I leave open until the end of November. In fact, if the temperatures are not too low, it’s essential to give the plants all the air possible even in autumn and winter, opening the greenhouses for a few hours on the hottest and most ventilated days. This simple expedient very much reduces the risk of onset and spreading of fungal pathologies. The “toughest” plants, such as Ferocactus and Echinocactus, will return to the outside of the greenhouse from the middle of March to help them get used to the direct sun gradually and avoid sunburn.

Succulent plants and summer: everything you need to know.

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L'articolo September is a brilliant month for all cacti, but pay attention to proper care ahead of autumn proviene da Il fiore tra le spine.

Now let’s see everything we can do at this time of the year, especially if we don’t have a greenhouse and we grow on the windowsill, on the balcony, on a terrace or in the garden. With a warning: whatever you have to do, with succulents and cacti, you must not be in a hurry: hurry to water, hurry to treat, hurry to move the plants… Getting caught up in the rush, the anxiety, the fear of doing something wrong, is the best way to run into mistakes. So let’s see how to avoid them. (…)

Check the plants

The first fundamental action in spring is to check the plant carefully for detecting any traces of bacterial diseases (dark spots caused by fungi) or parasites (particularly the mealybug/cochineal). In the first half of mid-March, even with healthy plants, it’s however advisable to carry out some preventive treatment by spraying stems and leaves with a specific pesticide (against mealybug and spider mite) and, about ten days later, with a broad-spectrum fungicide (attention: copper oxychloride should be used only when the plants are in stasis, so from March should be suspended). Both treatments – pesticide and antibacterial – must be repeated a fortnight after to ensure complete coverage of the plants.

Give as much air as possible

When the minimum temperatures have settled at 10/12 degrees, it’s essential to give succulents as much air as possible. Plants that have overwintered indoors (except for some species, a thing to avoid!) or in cold but closed environments such as a basement, a garage or a veranda should be moved outdoors and placed on windowsills, terraces, balconies. If plants have been overwintered outdoors, protected by sheets or layers of non-woven fabric, they should simply be uncovered so they can benefit from all the possible air. In these cases, it’s necessary to pay attention to the weather because prolonged rains in a period characterized by not yet high temperatures can be dangerous for succulents, which do not tolerate water stagnation in the soil and excessive humidity. The plants must be placed on a balcony or terrace protected from the rain or covered by a roof.

The sudden changes in temperature that characterize spring, with daytime highs above twenty degrees and nighttime lows that can drop sharply below ten degrees, should not worry: in nature, almost all succulents are exposed to similar conditions and indeed greatly benefit in terms of growth and flowering. Exceptions are succulents coming from areas close to the Equator, such as those from Madagascar (Adenium obesa, but also Uncarina, Alluaudia and Pachypodium) or some cacti coming from tropical regions of South America, such as Melocactus, Discocactus, Epiphyllum, Schlumbergera, Rhipsalis: these species need minimum temperatures not lower than 15-16 degrees and to be moved outside only later, in late spring.

Air is of fundamental importance for any plant, even more so for succulents, which do not tolerate environmental humidity nor water stagnation in the substrate. In open-air, the soil dries faster, the stems can transpire effectively, and the risk of bacterial attack is significantly lowered. Tight, closed environments without air exchange are to be avoided, especially in spring and summer, when succulents are in full vegetation, and their tissues are swollen with the water that constitutes their water reserve, and it is, therefore, necessary that the soil dries quickly after the plant has absorbed the liquids it needs.

Exposure: getting plants used to it

Closely related to air is exposure to the sun. In spring (in march), it’s necessary to provide succulents with more light to encourage proper development of tissues, leaves and thorns and at the same time encourage flowering. Be careful, though: as with all plants, succulents (including Cactaceae) need to be grown gradually. Moving a plant that has spent the winter indoors outdoors and immediately placing it in full sun can be dangerous even for the most “fierce” and thorny cactus, which will suffer sunburn and stem discolouration. We will have to gradually accustom the succulents to the light, which becomes more and more intense in spring, exposing them to direct sun a little at a time. From the middle of March, it will be sufficient to place succulents on a windowsill exposed to the South or Southeast (exposure to the North is to be avoided because it does not provide enough light), or on a balcony, a terrace or directly in the garden, taking care, however, to place them in the shade of outdoor plants that will act as a screen to sunlight. Alternatively, it is possible to protect succulents with a simple gardening net or with a piece of mosquito net properly fixed to braces or supports and able to screen at least 30-40% of sun rays.

In the shade of other plants or screened by shade netting, succulents will gradually get used to direct sunlight, and within a month to a month and a half, you can bring them to the foreground or remove the shade netting. As far as exposure is concerned, it’s still important to know the needs of our succulents since there are genera that tolerate intense sun and others that prefer a little shade (like many species of Euphorbia or Haworthia, for example). When in doubt, it is good to provide succulents with bright light all day long, exposing them to direct sun rays only during the morning, not later than midday. In this way, it’s possible to avoid sunburns and to guarantee the necessary light for the best growth. Particularly for cacti, which will continue producing “important” and not stunted thorns and at the same time keep compact and harmonious stems. When we have a better knowledge of our plants and have learned their needs, we can be more “targeted” when they come to exposure and give the various specimens the right amount of direct sun (for example, in the case of almost all cacti).

To learn how to distinguish succulent plants and know their needs, you can read this article dedicated to classification.

Resume watering

As the exposure to light, which should be gradual, watering should be increased little by little. During the winter, watering should be suspended for almost all succulents, while in spring it’s necessary to accompany the resumption with initially moderate and then more sustained watering. As spring approcaches, in March (weather permitting) a couple of waterings will be enough, while in April, it will be possible to go up to one watering every ten days, making sure to wet well all the soil. From May, you can further increase the watering, reaching one per week. Be sure that between one watering and the other, the loam can dry completely. As always, the advice with succulents is not to overdo it: it’s easier for a succulent plant to die from too much water than from thirst. Consider that these plants are xerophytes, evolved to deal with long periods of drought: when in doubt, it’s a good idea to postpone watering. For regulating the frequency of watering, it’s fundamental also the composition of the soil: here, you will find the “recipes” of various substrates that I have tested over the years.

Fertilize: which products to use

With the arrival of spring and the increase in watering, it’s beneficial to fertilize (or “manure”) succulent plants to promote balanced growth and encourage flowering. As for any other plant, fertilizing is essential to replenish the soil with nutrients that are lost. However, you have to use a specific fertilizer for succulents and not rely on universal products or, worse, calibrated for other plants, such as orchids or horticultural. Wrong fertilization, both in terms of the type of product and frequency, can cause severe damage to the plant and compromise its growth, arriving, paradoxically, to weaken it, as well as deform the stem. Therefore, it’s necessary to limit fertilization (I am very stingy in this regard: two or three fertilizations per year, at most), to be administered by simple watering diluting the product in water, to a maximum of once a month from April until mid-June at the latest, with a further pass in September, before the plants slow down the vegetation.

As for the product, on the market, there are specific fertilizers for succulent plants, and generally, high-quality products have correct ratios between the various macroelements. Knowing how to interpret the label, however, is the first step. Basically, it is sufficient to verify that the level of Nitrogen (indicated with the initials “N”) is considerably lower than that of the other two macro-elements that make up all fertilizers for plants, namely Phosphorus (indicated with the letter “P”) and Potassium (“K”). As an indication, a good fertilizer for cacti and succulents should have 1 part Nitrogen, 2 or 3 parts Phosphorus and 4 or 6 parts Potassium. The dosages indicated by the various manufacturers are variable, but it will be enough to keep these proportions in mind to choose the correct product. According to the most commonly used formulations, we can have a ratio of 6-18-36, or 5-15-30, where 5 stands for the Nitrogen dosage, 15 for the Phosphorus one and 30 for the Potassium one. Balanced fertilizers are to be avoided, those with equivalent dosages of the three macroelements (for example, 10-10-10). In addition to the three macroelements, a good fertilizer for succulents should not lack the so-called mesoelements and microelements, such as calcium, magnesium, sulfur, manganese, boron, copper, zinc, iron, which contribute to a balanced development of the plant in various aspects: root system, stems, thorns, flowering, disease resistance.

For the dosage, it will be sufficient to refer to the indications on the package, taking care to halve the quantities in order not to overdo the fertilization, since succulents are extremely adaptable plants with few needs in terms of nutrients, many of which are already present in the growing medium.

If you want to learn more about fertilization, you can read this specific article.

Don’t be in a hurry

In closing, by my experience and the constant contacts I have with readers and enthusiasts who ask me for advice, I would like to reiterate the concept expressed at the beginning of this article: with cacti and succulents, don’t be in a hurry, never anxious. Our plants are more robust and tolerant than we think: let’s make their time our own and not let ourselves be led by the frenzy of wanting to give them excessive attention. Let’s limit ourselves to the correct care and respect their times, which are decidedly less hectic and anxious than ours, remembering that the border between passion and obsession can be thin…

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Video

Here is a video of me moving some of my plants outside my greenhouse:

Correlated articles

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 Preparing cacti and succulents for spring: exposure, fertilizing, here’s what to do proviene da Il fiore tra le spine.

When they say that a picture is better than words. In this case, there are three photos, but the concept doesn’t change, and the difference between a cactus grown in a “natural” (or “wild”) way and one with a “garden-style”, based on basic notions and beliefs is quite evident. The plants I’m writing about are Ferocactus latispinus obtained from a 2012 sowing of mine. From that same planting, I’ve got at least forty plants. Over the years, I have given away some of them, but most are still with me and are growing beautifully. It’s important to point out that these are plants born from seeds contained in a single fruit (gift of a dear friend), sown the same day and grown over the years in the same conditions, i.e. in my greenhouse, in standard soil (pumice, lapilli and peat in equal parts), watered and fertilized with the same frequency. This is to say that the starting conditions, including the genetics and the grower’s hand, are the same. And yet, as you can see from the photo above, where the three plants (three at random of the twenty-five or so that I have kept for myself) are side by side, they show remarkable differences, at least to the discerning eye and the grower with a minimum of experience.

So let’s see, in this article, how and why different cultivation regimens, assumed as a whole and not just limited to the soil, affect so much the final result and really make the difference between a cactus grown and cultivated in any garden or generic nursery and a cactus grown by an enthusiast or an expert. (…)

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L'articolo How a cactus changes depending on the type of cultivation: the difference made by soil and exposure proviene da Il fiore tra le spine.

Colourful, flashy, ephemeral. Cactus blooms are sudden bursts of energy. Often the buds develop in a few days to open within few hours, amazing the newcomers to the cultivation of these plants and, above all, those who are not familiar with succulents. In these last few years, I have noticed that there is a lot of misinformation about cacti, in particular about their blooms. Those who do not cultivate these plants can even be surprised that they can bloom, no more or less than the specimens of all the other plant families, forgetting that the flower is the basis of the reproduction of almost all plants. Others are impressed to learn that even cacti can bloom in abundance and several times during the growing season, thinking perhaps that the flowering of a cactus is an exceptional event, almost unique. Nothing could be more wrong: all the cacti regularly bloom, and if there are relatively stingy species, that can produce few flowers for limited periods during the year, there are also really generous species, able to give blooms several times for entire months (for example Echinopsis, Astrophytum, Strombocactus, Gymnocalycium, Trichocereus).

In the following article we see in detail how to make cacti and succulent plants bloom abundantly. (…)

Introduction

If we have to find a flaw related to the flowering of cacti, this is in the fact that their explosions of colour are almost always ephemeral, not lasting. Some species (such as Echinopsis and Discocactus) produce large, flashy flowers that open at night and last only a few hours, so that from the middle of the morning after opening they begin to wither and become withered within 24 hours. Other genera, such as Gymnocalycium, can keep them blooming for two or three days, which is about the maximum that we can expect from a cactus plant. Once ascertained this and accepted the fact that we can not expect from our cacti persistent and long-lasting blooms such as those, for example, of orchids, what can we do to maximize the production of flowers of our cacti?

Plants in the right age to flourish: the primary condition

First of all: when do cactus bloom? Let’s start by saying that every type of cactus can bloom easily. The primary condition for flowering is as banal as it is essential. The plant must be of the age required for that particular species to flourish. For some genera, for instance, Mammillaria, Turbinicarpus, Gymnocalycium, Astrophytum, are enough from two to four years for having the first flowering. Other species require more time, flowering not before the age of eight or ten years (if not more, in some cases), as like Ferocactus, Echinocactus, Ariocarpus, Geohintonia, Aztekium. First, we must therefore know a minimum of the characteristics of the main species, for discerning, according to the age and the size of the plant, if we can trust in the flowering or if we will have to bear patience for a few years.

Here is a gallery with some spring blooms.

The importance of winter rest to make cactus bloom

How to get cactus to bloom? Once established that the plant is in the right condition to make flowers, the first rule in absolute is to ensure our plants a regular annual cycle of growth and stasis. Cacti and succulent plants, for blooming, need a period of whole rest, to recover the energies from the last blooming and to prepare for the next one. For the vast majority of the species, this results in some months of vegetation blockage, months corresponding with our winter and with the prolonged drought season that these plants cross in nature. In summary, we can say that in Europe, from the end of September, the cacti (except some species, in particular, the Chilean ones such as Copiapoa and Eriosyce, then many Escobaria, Sclerocactus and Pediocactus) slow down the vegetation up to enter into stasis. From this period onwards it will be useful to reduce the watering until it is suspended for October (in Southern Italy it is possible to water up to November, considered the mildest climate). In this way the soil will dry completely, they will avoid dangerous stagnations of humidity between the roots, and the plants will begin to deflate in preparation of the winter.

In addition to the stasis induced by the season and the suspension of watering, temperatures are fundamental for flowering. During our winter we must ensure that the plants feel the cold, then keeping them outside the houses, in greenhouses, sheltered terraces, basement, etc. Except for the Cuban species (such as the Melocactus) and of other species growing in subtropical zones (for instance, Epiphyllum, Discocactus), the vast majority of the cacti, if kept in dry loam, can easily stand temperatures just over zero celsius degrees. Many species can go well below zero (Opuntia, Escobaria, Pediocactus, just to name a few), but we can say that the best is to spend the winter with minimum night around 5 or 7 celsius degrees. The cold contributes decisively to the blooming, because, together with the dry, it puts the plants in complete stasis. Under these conditions the cacti block the growth, they rest, they recover the forces for restarting to vegetate in spring and to bloom regularly.

How, when and how much to water cacti and succulent plants?

Light even in winter to make a cactus bloom

It is often heard that during the vegetative stasis the succulents can also stay in little or not luminous places. Many growers, during the winter months, keep them under low light or in garages. Now, if it is true that once the plant has entered in stasis the lack of light does not cause damage (the plant is in fact in a block and does not grow, so it will hardly be able to spin, that is to stretch and deform), it is however indisputable that in nature, even with the change of season, the cacti do not stay for whole months in the dark (or almost). At most, they receive less light due to the shortening of the days and the different incidence of the sun’s rays. It is no coincidence that over the years I have verified that between plants that have overwintered in dimly lit areas and plants that have overwintered in environments exposed to maximum light even in winter (for example those kept in a greenhouse) there is a big difference in terms of flowering. Based on my experience, plants kept in the dark, bloom more hardly or not at all, while those held in bright areas even during the winter bloom abundantly and without any problem.

I have verified it in particular with the genus Notocactus (now called Parodia), according to many of the easiest to cultivate and among the most prone to flowering. For years, when I still didn’t have a greenhouse and in winter I had to repair the plants in a closed terrace exposed to the North, I had failed blooms if not even non-existent, in particular with this genus. Since I had the opportunity to transfer all my plants in my big greenhouse in the country side, all my Notocactus (as well as all other genera I grow) bloom punctually and generously.

How to make a cactus bloom: proper cultivation

Winter rest, cold, light are primary factors for the flowering of cacti. To these is added this factor if we want to take for granted but equally important: a correct cultivation in the year before the vegetative recovery. Plants that during the vegetative season have grown stunted, or have not grown at all or plants that have had problems with pests and fungal diseases will obviously have to think before recovering, rather than flowering. In other words, the cacti that during the previous vegetative season have struggled to survive may require more time to dedicate to the recovery, concentrating the energies, for example, on the reconstitution of the radical apparatus. Stressed, dilapidated plants, blocked by a repotting carried out maybe in an inconvenient moment, in short, could be more about their health than about flowering. Be careful, though: talking about flowering, this is by no means a rule. Let’s say rather a highly probable situation. I have, in fact, happened to see more than once plants in bad condition produce a beautiful bloom. In these cases, the stressed plants have begun to recover appreciably once the flowering has finished, thanks to proper cultivation based on regular watering, few fertilizations and the appropriate exposure to the sun (which should never be directed for plants in distress!).

Fertilizing: an important factor in making cactus bloom

Finally, two words about fertilization, necessary for every cactus to flower. Indeed, fertilization also helps in blooms, but I must say that I am quite thrifty with fertilizations. I do few and low dosages, but I think that if you use poor soils in humus (as I usually have) the fertilizations are useful for the purpose of a rich flowering. With the fertilizer, in fact, is going to adjust the soil, which for cultivation in a pot is available in limited quantities, adding those elements that with time and watering are gradually lost.

For more information on the relationship between fertilization and flowering, you can read my specific post at this link.

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Cactus cultivation cards
Fertilization for cacti and succulents
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 How to make cactus and succulent plants bloom: what you need to know and what tricks to use proviene da Il fiore tra le spine.

In the following article we look in detail at what we have to do in the run-up to summer to best prepare cacti and succulents and avoid problems. (…)

Aestivation

The slowing down of vegetation in cacti is called “aestivation“: basically in the middle months of summer many plants slow down or stop their activity, just “waiting” for the great heat to pass. It will therefore be a good idea to observe them well and try to tell from both the new spines and the stem whether they are in full growth or not, and adjust watering accordingly. Many succulent plants and many cacti, such as Agave and Euphorbias, Gymnocalycium and Echinopsis, have limited aestivation. For these, therefore, a watering regime appropriate to the rate at which the soil dries out can be maintained, watering as often as once every 7 to 10 days. The area in which you are growing succulents is also decisive: in North Euorpe, let’s say, you still should not overdo the watering, given the high ambient humidity rates, while in the South of Europe you can even go so far as to water almost every day if necessary.

A more in-depth discussion on watering can be found here.

Wanting to make an initial broad distinction, it is important consider that Chilean plants, such as Neoporteria (Eriosyce) and Copiapoa, from mid-June to the end of August stop or slow down their vegetation considerably. For these genera we can’t really talk about aestivation, but watering should be suspended altogether during this period, because there is a risk that, with the plant stopped and unable to absorb water, the soil will remain wet for a long time, triggering rot. Plants such as Echinocactus polycephalus, Sclerocactus and Pediocactus also slow down their vegetation significantly in summer and, like Copiapoa and Neopoerteria, should be kept dry and, if possible, in slightly shaded areas so as to contain the heat. Most cacti, on the other hand, simply go into aestivation in August, a month during which I use to suspend watering altogether. A special attention should be paid to the leafy succulents, such as Echeveria, Crassula, etc.: for these species it will be enough to adjust based on direct observation. If the leaves begin to shrivel and lose turgidity, you will be able to water. Otherwise, better to wait.

Fertilization

Also during the warm months, it’s better to avoid fertilization: plants “work” less and absorb less water, and fertilization may prove unnecessary or even harmful.

When and how fertilize cacti and succulent plants.

Pests and adversities

In July and August, with the great heat, conditions are created for the proliferation of the red spider mite, one of the main pests of succulents. Hot and dry weather are the factors that favor the presence of this pest, which attacks the tender parts of the plants’ stems. You can then resort to some spraying (which does not go to wet the soil, but only the aerial part of the plant) and a few of preventive treatments with specific products.

An article on pests and diseases of succulents can be found here.

Without a doubt, the best thing to do during the warm months is to encourage maximum air circulation. This obviously applies to those growing in greenhouses or partially sheltered areas: outside, plants enjoy normal air recirculation and are therefore able to tolerate the intense July and August sun and high temperatures. On the contrary, plants grown in greenhouses (even if open) have less air available and are exposed to temperatures that can easily exceed 40 degrees. There are many solutions: a shade can be placed on the roof of the greenhouse to contain the insolation, or all moving parts of the structure can be opened to the maximum. Finally, thermostat-controlled fans (or a timer) can be used for improving indoor air recirculation.

Seedlings

A separate discussion must be reserved for sowings: seedlings born in spring are not yet able to withstand long periods of drought, but they should be sufficiently developed by now to tolerate the wet/dry alternation. They can therefore also be watered during the summer, but allow the soil to dry out almost completely between waterings. Leaving seedlings completely dry for a month can drastically slow their vegetation or even lead to their death. Seedlings one or more years old, on the other hand, are better able to withstand dryness. For these, as for adult plants, the golden rule is observation: if the plants are swollen and turgid, they can be left to dry out during the hottest weeks. If they tend to deflate excessively you can provide for a focused watering. Remember that aestivation can also affect young plants!

Seasonal care in detail

If you want the complete picture of seasonal care, with what needs to be done in spring and autumn to best care for cacti and succulents, you can check out this article or this one.

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Correlated articles

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

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L'articolo Summer is coming: seasonal care for cacti and succulents, watering and aestivation proviene da Il fiore tra le spine.

First of all: why should we fertilize our cacti and succulent plants? Let’s say right away that fertilization (or fertilisation, or manuring or mineral nutrition) is necessary for any plant grown in pots, since the amount of soil available is limited and, sooner or later, nutrients will begin to run low. Fertilizer nourishes the plant, enriching the soil of those elements which, through the time, are absorbed by the plant or washed away by the waterings. Succulent plants should be regularly fertilized to ensure that the right quantity of nutrients is always available during the growing season. For cacti and succulents, however, generic fertilizers should not be used. In other words, a fertilizer commonly used for ornamental, leafy or fruit plants is not at all appropriate for a cactus plant. It is necessary to resort to specific fertilizers, specially balanced for the succulents. Otherwise, the risk is to irreparably compromise the growth and the physical appearance of the plant, making it weak and radically different from the specimens of the same species that grow in the wild.

In the following article we will go deeper into the subject, let’s see what elements succulents need, how the suitable fertilizer must be composed and how much to fertilize during the year. (…)

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L'articolo When and how fertilize cactus and succulent plants to have aboundant blooms proviene da Il fiore tra le spine.

Like any living thing, succulent plants need water. How, how much and when water depends on many factors, such as the time of the year, the place where you live (North or South Italy, for example?), temperatures, environmental humidity, the substrates you use, the size of the pots, and more… Before going into the details of watering, let us sure to definitively put aside false convictions legacy of who knows what experiences at the edge of the absurd. For example, let’s get the fact that cacti and succulent plants have to be watered with droppers or watered once in a blue moon.

General introduction

In nature, in the sub-desertic areas where these plants live, it often rains torrentially and for whole days. Or it rains every afternoon with the clouds discharge impressive quantities of water if compared to those we are used to seeing in Europe. For one thing, in many areas of Mexico (Baja California, for example, as I was able to experience during one of my trips), between September and October is time for extreme rains often accompanied by cyclones and hurricanes. From June to September, always in many sub-Saharan areas of Mexico, there are intense showers with daily frequency, especially in the afternoon. Moreover, in nature, the differences between night and day temperatures can be such as to produce abundant dew in the early morning hours: also this is water that many cacti can absorb to quench their thirst (not unlike the fog that surrounds, in Chile, the Copiapoa).

So it makes no sense to say tout court that cacti should be scarcely wet and at long intervals. In vegetative season, between the end of March and September/October, cacti drink well. Some species of genera like Sclerocactus, Pediocactus, Escobaria, Opuntia, also drink in winter. Other succulent plants – Africans, for example – can have inverted the cycle of the seasons, since while we are in summer at their latitudes in winter, therefore should be wet during our winter months and left dry in our summer months.

This is to say that, in addition to the factors of cultivation, we must first consider the basic conditions that plants have in their habitat. That said, some limits should be set. Just for a convention or because the times are mainly dictated by the temperatures, we can therefore say that basically the Cactaceae and the succulents of the Northern hemisphere must be watered in the period between the end of March and the beginning of October (better still, at least in Northern Italy, stop in mid-September to give time to the plants to prepare for winter).

What kind of water to use

If the question were: What is the best water for cacti? the answer would be clear: the rainy one. For those who cultivate in greenhouses and have the opportunity to collect rain in large tanks the problem would not even arise. Rainwater is definitely the best: it has an acidic pH and does not contain limestone or chemicals such as chlorine, to name one. In general, for plants, so not only succulents, it is the ideal solution (as well as the most natural, in all senses). It is not only its intrinsic characteristics that make rainwater the best: it is also the type of watering determined by rain that contributes to the final result. Exposed to rain, the plants receive water in variable but constant quantity, drop by drop for a time that can go from a few minutes (in the case of summer showers) to a few hours. Not only that: the water is enriched with oxygen and also this has a beneficial effect on the plants. To focuses it is enough to keep two identical plants and leave one to the rain, keeping the other to shelter and wetting it with tap-water. After a few weeks, the differences between the two plants will be evident: the one quenched by the rain will be more luxuriant, cleaner, more vital. More healthy, in short.

For those who have a greenhouse but can not collect rainwater, because it needs a peculiar system, or for those who grow on balconies or terraces, the alternative to rain is water for domestic use. In the countryside, as in my case, there is well water, generally quite calcareous and therefore, in the long run, less good for plants. One solution, in these cases, is to fill cans or barrels with well or tank water and let it decant for at least 24 hours, adding citric acid or specific products (available on the market) capable of acidifying it and bringing its pH between 6 and 6,5. Then, leaving the water decant for a day, the chlorine can evaporate almost completely, as well as any impurities or heavy elements can settle on the bottom of the container.

Generally, for my plants in the greenhouse, I do this: the day before watering, I prepare the water to use, leaving it in two tanks of 80 litres. Therefore, since in the countryside the water is ordinarily calcareous, I add the right amount of acidifier to sweeten it. After 24 hours, I water the plants using a pump connected to the pipe that draws water from the vessels.

I keep outdoor a very lot of plants (from three-year-old cacti obtained by seedling to adult Cactaceae, but also Agave and Aloe) from the end of March to the end of October. Needless to say, these get all the water the sky sends down. If, as happened during the last summers, it does not rain for weeks, I use the well water left to decant. On more than one occasion, however, the outdoor plants have been raining for several days. None plants died because, thank the air and the wind, the soil dries very quickly.

How to water

I water from above, wetting the plants and the soil. Since I use meagre or peat-free substrates, in many cases mainly mineral, I bathe abundantly and in more coats, until I submerge the smaller plants creating a layer of water on the surface. Not only that: usually I do at least two or three coats with the reed of water on each pallet until I see the water dripping abundantly from the drain holes of the vessels. With the soil I use, within a day (if the temperature is hot) the surface of each pot will be dry; in four or five days all the soil will be dry to the depth (also because succulents, in the vegetative season, drink quickly and with greed).

If clay field soil is used in the substrates, the watering must be abundant. It is necessary to revise several times on the plant because the clay, when dry, tends to be waterproof. It is crucial to insist, in short, that water can penetrate deep and well wet the bread of the earth. It is not by chance that this is how it happens in nature, with the rain insistently falling for hours until it penetrates the surface of the fields. In the past, at the first watering after the dry winter, I used to see that some plants did not swell, despite watering that I thought abundant. They were mostly plants in clay and inerts. After having realized that the clay was too dry and compact, I started to wet more frequently, but above all insisting more on each plant, I submerged the plants with water. Result? After a couple of days, they had fully recovered and had regained volume: the water had managed to penetrate in deep, and the Cactaceae had finally drunk enough.

Beware of other false myths, such as that about the delicate Ariocarpus, that people say it is almost resistant to water. Nothing is more wrong: in the vegetative season the Ariocarpus drink a lot, and it is only this mistaken belief that has led to thinking that these plants never grow. With abundant watering, the Ariocarpus speed up the growth (even if being Cactaceae, they are relatively slow in the development).

When to wet and how often

The answers to questions like when to wet and how often to water could be endless. As stated above, we must consider first the plants and their origin (for example, an Echinopsis and a Lithops have very different needs), then the factors of cultivation, starting from the area where we grow. About this topic, some conventions can be assumed. For most of the Cactaceae and of the non-caudiciform succulents (for instance, the Crassulas), the watering period matches the vegetative season. In North Italy, this is from the end of March to the end of September; in South Italy even October and part of November. I start watering at the end of March, if the days are hot enough, otherwise I wait for the beginning of April. I stop the watering in mid-September, even if it is still hot, to allow the plants to begin to lose fluids and to prepare for the winter.

Between the end of March and mid-September, I water with varying frequencies, approximately every 15 days, intensifying if necessary in the warmer months, when I can bathe every 8-10 days. Very important, after the dry winter, during which the plants tend to deflate (in some cases also remarkably) is to start gradually watering again. The first two or three waterings must be light, not as abundant as in June or July. In fact, the plants must start to drink little at a time because if they find water immediately available in large quantity they absorb it quickly with the risk of swelling so fast to break. It happened to me a few times. I had a Frailea, a Thelocactus and some Ferocactus that after the first two waterings have swollen immediately, with the result that the stem has split. The plants are not dead but taking a risk because the internal tissue if exposed, can be easily attacked by bacteria that then go to trigger rottenness (not to mention the aesthetic damage of a plant with a literally pierced coast).

As for the frequency of wetting, the old rule can be useful: in doubt, water only if the soil is well dry. We see it from the superficial layer: if pressing with the finger, we feel humid, better to wait. This is a basic rule based on common sense – it is difficult for a cactus to die of thirst, but it is easier that it can rot for an excess of water, especially if in very organic soil. Then the experience will tell us when to give water to our plants. To me, for example, it is enough to touch the stem or weigh the pot to understand if the plant is thirsty and if the soil is still wet or not.

I reserve special treatment for my Cactaceae seedlings of at least one year and for the few succulent plants that I have (Crassula, Echeveria etc.): for these, the frequency of watering is greater than the Cactaceae in general. Leaf plants obviously tend to disperse water more than cacti, while the seedlings have the desire to grow and to support them are wetted more frequently than adult plants.

In August, usually, I suspend watering for cacti (not for seedlings and not for succulents in general). The Cactaceae, in the hotter months, tend to go in estivation, that is slow the growth and in some cases block it to restart as soon as the temperatures return to tolerable levels (in August in my open greenhouse the temperature can exceed 40 degrees). For the plants I keep outside in the vegetative season, as I wrote above, I leave it to nature. They can take water for days and days or stay whole weeks in the dry. If the drought extends, I provide with extra watering.

Regarding the times in which it is better to wet the plants, it is better to do it early in the morning, before the sun begins to raise the temperatures, or in the late afternoon. Even better in the evening, so the plants will have all the night – basically with lower temperatures than the day – for absorbing the water before it can evaporate on the surface of the pot.

It is essential do not water immediately after a repotting: the roots may have been damaged during the operation; it is good to wait at least ten days before wetting the soil, to allow the rooting apparatus to heal its wounds and avoid the risk of rot that wet soil could trigger.

Nebulization

Some recommend spraying the succulents often. I do not find it useful. I did it for years, at first, then I saw that the plants had no benefit at all. Even to nebulize them abundantly, in a few minutes they completely dry and I do not see the point in wasting time to wet the cactus and succulent stem. The only useful nebulizing, in my opinion, is that with water added with fungicides or acaricides. Over the years, since I have strengthened the plants with the cultivation regime and the soil I use, I have reduced these treatments a lot. Usually, I give the copper once in spring and once in autumn, before dry, and an acaricide a few times during the growing season.

Fertilization (or “manuring”)

I discuss fertilization (also written “fertilisation”) in a specific post, at this specific link. Here it is enough to recall that cacti and succulents must be fertilized with specific products with low nitrogen content and not generic, for example for ornamental plants or for the vegetable garden. The fertilizers for succulents are based on nitrogen (N), phosphorus (P), potassium (K), to which various micro-nutrients are added. For succulents, in general, it is good that the ratio between the three main elements, N-P-K, is in the order of 5-15-30 (another basic formulation used is 1 of nitrogen, 2 of phosphorus and 4 of potassium). Fertilizers, in good substance, little nitrogenous and with high percentages of phosphorus and potassium.

Watering and repotting

Caution: freshly repotted succulents should never be watered. It is good to wait at least ten days from repotting before wetting the soil. The repotted plants may be nebulized so that the topsoil can get settled the surface, especially in the cases of habitat reconstruction, but for wetting the earth in-depth is better not to hurry.

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© 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 How often and how much to water cactus (cacti) and succulent plants and which water to use proviene da Il fiore tra le spine.