Euphorbia obesa, care and cultivation from A to Z

Today I want to dedicate a short video to a succulent plant that attracted my curiosity for various reasons, in particular:

• there is one strange shape which earned her the epithet of “baseball facility“;
• not only do I find it fascinating, in fact it has been awarded by the Royal Horticultural Society, winning the Award of Garden Merit;
• the fact of being dioecious (on the shop you can find both: Euphorbia obese male and female), even if sometimes it is possible to find phenomena of hermaphroditism;
• it is a curious example of evolutionary convergence.

Today let’s talk about her: Euphorbia obese!

Euphorbia obesa

Euphorbia obesa, also known as the «baseball plant» due to its spherical shape, is a decorative succulent that does not go unnoticed. Originally from South Africa, this particular plant stands out for its globose stem without thornswhich can reach a diameter of 6-15 cm depending on age. While when young it takes on a perfectly rounded appearance, over time the Euphorbia becomes obese it tends to stretch slightly upwardscan even reach 25-30 cm in height.

The number of crests that we can see on the stem is quite stable, in fact there are usually 8, decorated by gibbons that trace the crest. Every time we see a specimen, it could surprise us, in fact we could notice new differences from plant to plant, especially in the color of the globe which exposed to different light intensities it responds in a typical manner remaining more green/blue, sometimes veering towards purple tones, arriving, in some cases, to become bronze brown.
Usually, it is a succulent that grows singly, but occasionally it can develop suckers that form small spheres at the base of the stem. The leaves are extremely small and tend to fall off quickly, fortunately this is not a big problem for the plant as the stem is also capable of carrying out chlorophyll photosynthesis. The inflorescence, called cyathium, is a cup-shaped cluster composed of modified leaves enclosing unisexual flowers. These flowers are rather small and not very significant, the aesthetic power of the plant is in fact given by the particularity of the stem.

Be careful, latex is toxic like other Euphorbias.

Euphorbia obesa care and cultivation

Temperature of Bigeye Euphorbia

I’m a bit nervous about Euphorbia, a vast genus of thorny and non-thorny plants (here we are in the second case). Last year I started growing a «White ghost» which, like some other Euphorbias, is a little more sensitive to frost than the others, for this very reason, at a certain point, I was about to lose it, fortunately then, at the beginning of winter, I moved it to a place where it could have its 15°C and everything worked out in the best way 😉

Unlike most ‘fat succulents’ this genus has some more difficulty in approaching zero, with Euphorbia obesa it is possible to stay on 9-10°c, if the area is cleaned.

Somewhere I found even minimum temperatures of -5 tolerated, let me know if you have experience at these temperatures, I’m a little reluctant to do the test.

Euphorbia obesea exposure

Euphorbia obesa loves light very muchthe color of the stem changes based on the type of radiation it receives, certainly a lot of direct light, especially in the central days of summer, even a few hours of more intense sun could give rise to a fascinating change in the plant towards bronze tones, this is normal. In bright but not direct environment instead it maintains this beautiful bright green blue color.

Browning responds a bit like our skin reacts with tanning, according to some it is still an avoidable stress that can slow down the growth of the plant, I will also do some experiments in this case to understand how things are, but let me know if any of you have already tried it.

A good compromise is that of one only partial direct light in summer.

Substrate for Euphorbia obesa

To avoid rot, it is important to choose a suitable soil for succulents. If you are in cooler areas, where the soil tends to dry more slowly, it is advisable to add between a third and a half of pumice to the substrate. This measure is essential because the soil must dry quickly; without an appropriate substrate, the plant risks rotting.

When to water Bigeye Euphorbia?

Watering is an important aspect for Euphorbia obesa, here’s how to do it based on the time of year:

• in summer: when the soil is dry, water deeply but infrequently.
• in winter: suspend watering, with the exception of sporadic sub-irrigation interventions, only if the soil is extremely dry. Better to wait until spring to resume regular watering.

Which pot should you use to repot Euphorbia obesa?

For Euphorbia obesa it is essential to use a perforated pot and proceed with repotting only when necessary, switching to a slightly larger pot of about 2 cm, as the plant fears overpotting.

Euphorbia bigeye reproduction

Propagation of Euphorbia obesa can occur via seeds or cuttings. I advise you against propagating Bigeye Euphorbia from seed because it is a rather complex process: during spring or summer, the seeds should be planted in sandy, loamy soil, maintaining a high level of humidity. Germination occurs in about three weeks. By using cuttings instead, you can exploit the offsets that develop at the base of the plant, perhaps being careful to cut them as close as possible to the main stem. Then it will be sufficient to let them dry for a few days until the surface of the cut has dried out and formed a callus. Next, plant the cutting in a mix of sand, potting soil and pumice.

Bigeye spurge flowering

The flowers of Euphorbia obesa are small and yellow and can be seen appearing from the top to the stem from April until July. A curious thing, but which in reality is also common to other types of plants, is that if after being pollinated the Euphorbia gives rise to seeds, these will be exploded from the capsule in which they are contained by flying for several metres. This is a strategy that is adopted in nature to allow the plant to spread further.

Evolutionary convergence in Euphorbia obesa

Evolutionary convergence is when different species living in similar environments develop, due to the same environmental pressures, similar structures or adaptations through natural selection. These species are called convergent.

Astrophytum asterias (sea urchin cactus) and Euphorbia obesa exhibit this phenomenon. Although they live on different continents (the first is a cactus from Mexico), they have developed similar shapes to adapt to similar environmental conditions.

Euphorbia male and female

In the shop you will find Euphorbia obesa in several sizes, but above all you will find male or female, this is because, as we said at the beginning, Euphorbia obesa is a dioecious plant, like, for example, the kiwi. They are plants that evolution has endowed with two separate sexes on different individuals, therefore there is the male plant which produces pollen but not fruits, and there is the female plant which after being pollinated produces flowers, fruits and seeds. The male plant is equipped with stamens with the anthers at the apex, while in the female we do not find the male parts, but instead we find the pistil with the classic three-body shape.

In these plants it can be observed hermaphroditismthat is, the change of sex from female to male when there are no males available for pollination.

Euphorbia obesa and the risk of extinction

Euphorbia obesa is threatened with extinction in the wild due to overharvesting, poaching, its slow growth and the fact that each pod produces only 2 or 3 seeds. However, it is cultivated on a large scale, making it, in fact, not endangered.

My advice is always to grow them outside and not as houseplants where in the absence of other options they can still grow without problems but in short we know this thing well by now, if we want to replicate the conditions that the plant goes through in nature the winter temperature range will allow the flowers to appear!