Without dwelling too much on the broad field of plant classification (here, if you want, you will find an article dedicated to this topic) and taking it for granted that the term “succulent plants” refers both to cacti and to many other succulent botanical families whose specimens have a different appearance from any other cactus, we are addressing a very “heartfelt” topic among novice growers. Even the grower who boasts a good knowledge of a given family, however, may find the following article useful, which recommends succulent plants (belonging to various botanical families) that are less demanding, more robust and simple to grow and therefore more suitable for those who are only now approaching the world of succulents. (…)

Premise

With a minimum of initial documentation and experience it is possible to grow all succulents without particular difficulties. Striking down to the essentials, the main cultivation elements to take into consideration are the substrates, watering, exposure and temperatures. In many cases these elements may be common to different types of succulents, for example the substrates, which for succulents must always be very draining, rich in inert materials and able to dry quickly. Other cultivation factors, however, can vary enormously from family to family but also from genus to genus. Some examples: cacti tolerate the cold well, while succulents originating from Madagascar or some African areas (e.g. Adenium, Uncarina, Pachypodium) cannot resist temperatures below 15-16 Celsius degrees. In the same Cactaceae family we find genera that are very resistant to cold (Echinopsis, Pediocactus, Opuntia) and genera that do not tolerate low temperatures (epiphytic cacti such as Epiphyllum, Schlumbergera, Rhipsalis or Melocactus and Discocactus).

This is why, for those who are only now approaching the cultivation of succulents, it is important to know which plants to start with in order to accumulate experience and best cultivate the newly purchased plants. The discussion, as mentioned, applies as much to cacti as to all other succulent families, since an enthusiast can be an expert in cacti and approach other families for the first time, such as Crassulaceae, Aizoaceae, Apocynaceae, Euphorbiaceae, etc.

Cactus

Let’s start with cacti. The first genera recommended to those who have no experience with these plants are undoubtedly Echinopsis, Gymnocalycium, Rebutia, Parodia (=Notocactus), Opuntia, Ferocactus. Be careful, there are many other cacti that are easy to grow but if you have to suggest some kind, you can’t go wrong with these. These are genera that group together very robust species, with few demands, capable of tolerating many cultivation errors and at the same time easily giving abundant and splendid blooms.

Attention: in some cases by clicking on the genus you will be directed to the downloadable PDF cultivation sheet of that same genus: a useful and detailed tool (4 pages) to deepen your knowledge of those plants.

Echinopsis are very common plants, extremely robust and able to tolerate the cold very well. They are therefore ideal for those who do not have a greenhouse or winter shelter (cold environment, necessary to encourage flowering). Echinopsis can spend the winter outdoors, often even in damp soil, although it is advisable to place them under a shed or porch. In spring and summer they produce showy flowers with a large corolla and long calyx.

Gymnocalycium are plants of South American origin (Argentina). They are easy to grow, tolerate the cold well (not frost: it is best that they do not go below 5 Celsius degrees and always in dry soil) and have growth rates that are not particularly slow. Furthermore, the genus brings together a large number of very different species and even just by cultivating Gymnocalycium it is possible to set up a very respectable collection. They flower in spring and summer already 4 or 5 years after sowing.

Other cacti recommended for those with little experience are the Rebutia. These are plants of South American origin, generally globose and with a tendency to cluster. Cultivation is very simple and their strong point are the flowers. In spring, these cacti produce an impressive quantity of medium-sized flowers of various colors depending on the species.

Parodia (once classified as Notocactus) are robust and very easy to grow cacti. They are satisfied with little care, have growth rates that are not excessively slow and produce beautiful blooms at the apex during the summer. Depending on the species, the flowers can be yellow, purple, red, orange. Even the thorns are variable from species to species and you can go from plants with slender and thin thorns to plants with very respectable thorns (P. maassii, P. buiningii).

Opuntias are bombproof cacti. They grow quickly, tolerate intense cold, multiply extremely easily by cutting and in many countries they can grow in the open ground, even exposed to bad weather during the winter. They can reach large dimensions (especially if grown in open ground) and produce beautiful flowers with colors ranging from pink to red, from yellow to orange.

Finally, for lovers of thorns, the first genus to recommend is Ferocactus. These are very robust cacti, always equipped with notable thorns, easy to grow, as long as they are guaranteed plenty of light, and grow relatively quickly. Some species flower relatively early (F. macrodiscus, F. schwarzii), others require at least a dozen years to produce the first flowers. Many species of Ferocactus can reach considerable dimensions even if grown in pots. However, those who have little experience with cacti should avoid starting with Ferocactus johnstonianus and Ferocactus lindsayi: two slightly more demanding and slow-growing species.

Crassulaceae

If you’re not particularly fond of thorns, the Crassulaceae family offers a wide variety of succulent genera and species. This family includes genera such as Aeonium, Adromischus, Crassula, Echeveria, Kalanchoe, Graptopetalum, Pachyphytum and the immortals Sedum and Sempervivum. Recommending a genus or a single species is almost superfluous: all Crassulaceae are easy to grow, very decorative, resistant and have good tolerance to cold. Having to indicate a couple of plants of this family, we can mention the very widespread Crassula ovata, called “jade tree”, with a small tree shape and oval, fleshy and bright green leaves. Another very interesting genus from an aesthetic point of view and easy to grow is that of Echeveria: plants of Mexican origin, very robust and with a characteristic rosette shape. Thanks to the high number of species and the many crossings carried out over the years, an infinite variety of Echeveria is available, with colored leaves that can range from blue to red.

Euphorbia

The Euphorbia family is very vast and includes very different genera. You can go from plants with a rounded stem without thorns, such as E. obesa, to plants with a columnar, curled shape, with leaves and thorns. Overall, the cultivation of Euphorbia is simple, but there is no shortage of species that require some experience. To begin with, E. resinifera, a very resistant and adaptable plant, E. enopla and E. obesa, beautiful and with an epidermis characterized by fascinating striations, can be indicated.

Agaves

It’s hard to go wrong with Agaves. These are very robust succulents, extremely adaptable and very easy to grow. In reality, they can almost be ignored completely: if placed in draining soil they are satisfied with rainwater, they resist intense sun and cold very well, to the point that in many regions they are grown in the open ground. They have rather rapid growth rates and many species can reach considerable sizes within a few years, particularly if kept in open ground.

Aloe

Even Aloes, in some ways similar to Agaves, are succulent plants suitable for those who are approaching the world of succulents and do not yet have much experience. Compared to Agaves, however, Aloes (succulent plants of African origin) tolerate intense cold less and should be kept at minimum temperatures no lower than 6-7 degrees. To begin with, you can start from the common but always elegant Aloe vera, a robust and relatively fast growing plant. Other very widespread and easy to grow species are Aloe arborescens and Aloe variegata, very easy to propagate and very generous with blooms.

Hoya

Finally, a succulent plant belonging to the Asclepiadaceae family. Hoya has seen its popularity grow among green enthusiasts in recent years. Aesthetically it has little in common with other succulents, but it is still a very decorative plant, also suitable for home cultivation and capable of producing beautiful cluster blooms. The star-shaped flowers are very particular, they have fleshy and smooth petals to the point that the Hoya themselves are also known as “porcelain flower” or “wax flower”. The plant produces long stems from which thick and fleshy leaves are formed, ranging in color from dark green to bright green, up to green streaked with yellow. Cultivation is simple and growth is relatively fast. Furthermore, Hoya also tolerate relatively low temperatures well, around 10 Celsius degrees.

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Correlated articles

• Recognising succulents plants and cactus
• How to grow succulents
• Most frequent questions and doubts
• All cultivation cards in pdf
• Distribution of cacti and succulents: maps

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Keep on reading the article if you want to know how this story goes (…)

Well, if on the one hand, I would still like to see my expression immediately after having smelled that flower, on the other hand, the joke of that nurserywoman has forever imprinted in my memory my first encounter with a Stapelia (in this case a Stapelia gigantea), but above all with its flower, as beautiful and showy as it’s terrible, disgusting in terms of smell. And on the other hand, this is the main characteristic of almost all the plants belonging to the Asclepiadaceae family: their flowers, be they the small ones of the Piaranthus or the huge ones of certain Stapeliads, have a terrible smell. The smell they give off is that of rotting flesh, in particular, and there’s a specific reason Nature has chosen this for them.

Let’s see why this large family of succulents is condemned to produce flowers with beautiful shapes, incredible streaks and yet terribly smelly. Let’s get to know better the Asclepiadaceae, the various genera belonging to this family native to Africa and let’s learn how to correctly cultivate its species.

Origin and provenance

The Asclepiadaceae family includes about two thousand species and almost 250 genera, a quarter of which are succulents. In the last years, the classification has changed the Asclepiadaceae family to a subfamily included in the Apocynaceae family, but for convenience and brevity, I will write here of “family” referring to the Asclepiadaceae. First of all, it must be said that not all Asclepiadaceae are succulent plants: in this large family, you can find herbaceous plants, leafy plants, bushes, trees and even lianas. The origin of these plants is mainly African, in particular the temperate, tropical, subtropical and desert regions of the African continent. However, their distribution is not limited to Africa: some genera of the Asclepiadaceae family are native to the American continent, others to the Arabian Peninsula to China, and others to Oceania. Finally, two species are of European origin: Caralluma mumbyana and Caralluma europaea, actually native to the extreme South of Italy (Lampedusa) and North Africa (Morocco, Tunisia, Libya).

Maps with the distribution of succulents in the world.

Flowers are of various sizes and go from the few centimetres of Hoya to the huge ones, up to about thirty centimetres, of Stapelia gigantea, but they are always star-shaped, with five sepals and five petals joined together at the base.

The most known and cultivated genera

As for the lovers of succulent plants, the most appreciated and cultivated Asclepiadaceae belong to the group (or “tribe”) of Stapeliae. In this group are included: the genera Stapelia, Caralluma, Duvalia, Echidnopsis, Frerea, Hoodia, Huernia, Orbea, Piaranthus, Pseudolithos, Tavaresia, Whitesloanea. Among the Asclepiadaceae not belonging to the Stapeliae group, more cultivated by the lovers of succulents, there’re Hoya (the epiphytic plant with “wax flowers”), Ceropegia and Fockea. The species of the group Stapeliae are almost all characterized by fleshy stems and tufty posture. In some cases, they develop proper succulent branches, in others, they form rounded or short-cylindrical “articles” (as with the genus Piaranthus). In other cases, the stem is like a sculpture, similar to a small monolith or a rock (e.g. Pseudolithos and Whitesloanea). Totally different is instead the posture of Hoya, which develops very long stems from which fleshy, thick leaves come out. Ceropegia has a similar appearance, while Fockea forms big brown caudex (caudex is basically the thick and wide stem) from which long branches with small, not fleshy, leaves of an intense green colour branch out.

Why do the flowers smell?

Let’s start by saying that not all the flowers of the Asclepiadaceae deserve the nickname of “carrion flower” or “stinky plant”, with which Stapelia flowers are usually associated. Many flowers of plants belonging to this family produce perfume or ugly odour, as in the case of Hoya, whose flowers grouped in clusters have a beautiful shiny appearance, perfect, to be defined as “of wax”. Same for the flowers of Fockea, not very evident and without any particular smell or fragrance. They certainly deserve the definition of “carrion flower” many other genera, almost all belonging to the group Stapeliae, particularly the flowers of Stapelia and those of Piaranthus.

Why this curse? Why do such showy, beautiful and colourful flowers give off the smell of rotting flesh? Simply because the pollinating insects of these plants are flies, and it’s to these insects that these plants rely on to multiply. The most emblematic example is Stapelia hirsuta (the plant you can see above, under the title), which produces large star-shaped flowers, blood-red in colour to recall the colour of meat, and smelly, just like rotting flesh. The flies are strongly attracted to it: they pass from one flower to another just as bees do with any flower, pollinate the Stapelia and lay their larvae inside the flower, which, however, drying up, will prove to be a deadly trap for the larvae themselves, condemned to die inside the closed flower. If the smell of rotten meat is typical of the species of the genus Stapelia, many other Asclepiadaceae produce smell even if with different “fragrances”, as in the case of Piaranthus, Orbea and Pseudolithos, just to mention a few. Finally, as for the flowering period, almost all the Stapelia‘s plants group flower in autumn until the beginning of winter. An element, this one, which can interest those who want to enjoy blooming for almost the whole year, if they place side by side to the cultivation of Cactaceae the cultivation of Asclepiadaceae.

Cultivation regime

Staying in the Stapeliae group, which is of interest to succulent growers, it should be noted that Asclepiadaceae need a very different cultivation regime than the one effective for Cactaceae. Firstly concerning the minimum winter temperatures, which should be kept under control so that Asclepiadaceae do not go down 7-8 Celsius degrees. Fundamental, as for cacti, is that the plants remain in full dry soil from October to the end of March. If we see that the stems begin to lose too much turgidity, we can give little water on sunny days. I recover my Asclepiadaceae in an unheated cellar, with minimum temperatures between 6-8 degrees. At night, in the greenhouse, it can go down to 0 degrees, and I prefer not to risk it. Even about the exposure, the differences with most of the Cactaceae are of relief. The Asclepiadaceae of the group Stapeliae do not go exposed to the direct sun if not in the morning. From when the sun gets warmer, around midday, the plants should be sheltered in a greenhouse or by a shading net or, again, placed behind plants and shrubs that can give them shade. If kept in too much sun, Stapeliae suffers, slow down their vegetation and become extremely red. In summary: give them lots of light but not direct sun.

Watering should be done only from the end of March to the end of October but without exaggerating because these plants are sensitive to water stagnation and environmental humidity. Watering should be reduced, therefore, and the soil should be very draining. About the substrate, some grow Asclepiadaceae succulents in mineral soil, without organic (peat or humus), mixing pumice, zeolite, akadama, gravel, etc… Other growers keep them in only pumice, which promotes rooting and retains excess water by releasing it little by little. I’ve been growing these plants in the usual mix of equal parts peat, pumice, and lapilli, but I’m gradually switching to pumice alone, which requires more frequent fertilizing because it doesn’t provide much in the way of nutrients. Alternatively (as I did in the video at the end of this article), you can use a substrate made of pumice with the addition of a few humus (10%) and not much sand to give a minimum of nutrients and to add a good part to the compost, which with only pumice would be too coarse.

The soils to use with succulent plants.

In his book, Giuseppe Lodi advised to grow the Asclepiadaceae “in rather oily soil, but very permeable and sandy at the top”. He suggests it just to ensure that the collar does not remain wet for too long, being easily subject to rot. Always noted Lodi: “It is advisable to put a rich layer at the bottom (more leaf mould than sand and soil), then an intermediate layer with more sand and an upper one even more sandy” (Giuseppe Lodi, “Le mie piante grasse” – Edagricole).
For the rest, the cultivation rules indicated for most succulents are valid: as much air as possible and sparing fertilizations with specific products for succulents only during the vegetative season.

Main adversities

Collar rot and cochineal mealybug are the main problems in the cultivation of succulent Asclepiadaceae. To preventing rottenness, it’s advisable to moderate watering, use correct substrates and give as much air as possible to our plants. Against mealybug, the same cares are more or less valid since proper cultivation is the best prevention. Also, as a preventive measure, it’s possible to use specific products in particular periods. A few passes of copper oxychloride by spraying the stems at the end of the growing season and just before spring, for example, and Neem oil, again by showering during the warmer months (here a specific article). Against mealybug, some recommend inserting two or three balls of mothballs in the soil, a little deep. I have never tried this method, but I have heard of it several times.

Propagation

The multiplication of Asclepiadaceae can be done, as always, by seed or by cuttings. Seeding is necessary for those kinds of plants that do not branch, such as Trichocaulon and Whitesloanea, while cutting is the fastest method to reproduce genera such as Stapelia, Orbea, Caralluma, etc… It’s enough to cut a branch with a sharp cutter, let it dry for a couple of weeks in an airy place, sheltered from the sun and then place it on pumice with a superficial layer of sand. At that point, it’s possible to nebulize the stem and the substrate’s surface once every two or three days, thus favouring the rooting of the cutting. Obviously, reproduction by cuttings must be done during the vegetation period, therefore from late spring onwards and never in winter. Moreover, to avoid rottenness, it is better to sprinkle with copper oxychloride powder both the mother plant in the point where the branch has been cut and the cutting itself.

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Repotting of Asclepiadaceae: the video

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