How to Grow Euphorbia obesa

Written byJen Greene

Animal lover, plant enthusiast, and addicted to the sunshine and warmth in San Diego.

July 26, 2021

I wasn’t necessarily the biggest fans of Euphorbias to start. The white, toxic sap is pretty annoying, and they don’t produce the big, showy blooms that cacti do. 

But, on the other hand, the spines are generally less irritating, or in the case of these little succulent spheres, they’re non-existent! 

Euphorbia obesa was one of my first euphorbia loves. I stumbled across them for the first time at a little succulent cafe years ago, and it was incredibly difficult to find them for sale in the US. For a short time in late 2019 and early 2020, they were a little more available, but have been hard to find at the 4″ size that I bought most of mine as. 

My first Euphorbia obesa was a two-headed specimen I found at a 2018 cactus and succulent society sale.

With this first, two-headed plant, I made all my initial learning mistakes. Too much sun, too little, not enough water, too much, too hot, too cold, you name it, I did it. 

As long as you watch them, and adjust what you’re doing accordingly, they’re generally super forgiving. 

I’ve ended up picking up multiple Euphorbia obesas, with the goal of producing seed and growing my own inventory over the next few years. I like the obesas with some character on them, which is a good thing, because it’s nearly impossible to grow them perfectly to any significant size, unless you have a greenhouse and a skilled hand. 

euphorbia obesa

General Care for Euphorbia obesa

These are, genuinely, extremely hardy and easy to care for plants. If you can grow a haworthia, echeveria, or run-of-the-mill garden store cactus, you can do baseball plants.

Soil and Potting 

These like well-draining soil, and should have a mix that’s about 30 – 50% pumice mixed with a quality cactus and succulent soil. If you’re in a climate that’s dry more often, use more soil, and if you get regular rain and high humidity, add more pumice. The main thing is allowing the soil to dry out each time before you water again. 

You also shouldn’t overpot these (a mistake I definitely have made). They can be potted into a 4″ pot and then grow happily there for years, just getting their soil refreshed every other year. These little succulents stay quite small, developing height with time and seldom getting larger than 3 or 4″ across. 

Their small mature growth and correspondingly small root systems make them ideal container plants, which is another aspect contributing to their popularity. 

Euphorbia obesa

Watering and Growth Cycle

In the wild, these are winter-growing plants, but they’ll grow pretty much any time of year if provided with adequate water. 

“Adequate” water means that whenever they’re dry, they get watered again, with maybe a day or two of being left dry before the water is added. They like regular water, but not too much – too much will make them rot out quickly. 

When it’s hot out (like it is here in San Diego right now), they can take water every few days. In winter, when it’s colder, it’s more like once every week or two. Even though they’re winter growers, it’s more a result of water access than it is temperature – too cold and they won’t grow, even if it is their usual growing season. 


Euphorbia obesa do best in partial shade, particularly during the hottest part of the year. In too much sun, they’ll develop stress coloration, which is an orange-tan-brown shade, like the plant pictured right. While this coloration can be attractive, the stress of protecting itself against the intense sunlight can make it grow more slowly than same-size plants grown in shade. 

I find mine thrive best with 2 to 3 hours of morning sun, and full shade the rest of the day. I recently moved them to my greenhouse, where they are protected with a 40% shade cloth. The greenhouse is full sun, so the shade cloth is necessary for nearly all the plants. 

sun stressed euphorbia obesa
Euphorbia obesa

The euphorbia above shows unripe seeds with the little 3-pronged stigma stuck on top. 

At right, you can see unfertilized female flowers all clustered on the top. Usually, bees, butterflies, or even just regular flies or ants will pollinate these. The little stigmas are kind of large, and the relatively large yellow stigmas are how I tell the difference between a male flower and a female flower. 


Sexing your Euphorbia Obesa

One of the things I like most about these plants is that they have a fun little surprise: if there’s not enough of a given gender of the plant, they’ll swap!

So even if you pick up a male or female plant, there’s an excellent chance they’ll just switch what gender of flower they produce.

Female flowers have three little antler-shaped stigmas, no pollen, and when pollinated, produce seeds.

male euphorbia obesa

At right, you can see the base of the seed pods just peeking through the base of the flower. 

Interestingly, on a couple, you can also see one or two anthers poking up from the same flower. 

Male Euphorbia Obesa

At the moment, I only have one male euphorbia obesa, but my two-headed specimen seems to be in the middle of flip flopping. 

Male euphorbia obesa flowers have little white, puffy looking bases with three little anthers that stick up and have the pollen. Female flowers, if you look closely, have the base of their seed pods peeking out of the flower base. Male flowers will just have the white base. 

female euphorbia obesa

Collecting Seeds

Euphorbia obesa, like other euphorbias, creates seed pods that will violently explode when ripe. If you have more than one plant, and they’re making viable seeds for you, you’ll need to catch them somehow. 

I’ve seen people put the plants in buckets and then cover the top with a screen, I’ve seen people use the little tents you can get to cover food that’s out at a picnic, and I’ve seen people use jewelry bags! It doesn’t matter much what you use – just that you’re able to collect the seeds easily. They will go everywhere

Growing from Seed

Euphorbia obesa is quite easy to germinate from seed, but can be a bit challenging to grow to a size that is robust.

I’ve successfully grown about a dozen from seed, but lost nearly all of them due to rats eating them – so be aware that rodents will love to eat your seedlings! 

Use moist sterile cactus and succulent soil, and place your seeds on top of the soil. Lightly sprinkle play sand over the top – just the lightest layer to keep the seeds in place, but not so much you block out light. Place in a humidity chamber (covered with plastic wrap, in a germination pod for starting garden plants, or place the pot in a plastic bag), and then pretty much leave them alone for a few months. They should sprout within a week. 

You’ll want to mist your seedlings occasionally so they don’t dry out completely, but within 6 months, they should be established and ready to leave the humidity chamber. You can divide them up into 2.5″ grow-out pots at this point, or give them another month or two to get acclimated before dividing. 

They take at least 2 years to reach about 2″ or so, or the smallest size you might consider robust enough to offer for sale. More often, plants you see for sale are 3 years old or older, or grown under artifical lighting to encourage a longer growth cycle than natural daylight. 

Thanks to rats eating my seedlings, I can’t tell you much about their growth after the first year based on personal experience, but I have been able to watch batches mature at my favorite wholesalers. They are small plants that mature slowly! 

euphorbia obesa two headed

My two-headed Euphorbia obesa now! It’s been 4 years, and it’s big enough to fill up its 6″ pot. You can see some of the “bark” developing at the base, and with minor scarring up the sides. 

No two euphorbia obesa are the same, with their patterns, scarring, and growth all giving them a look that is subtly unique for each plant. 

Definitely a fascinating, fun little plant that is worth adding to any cactus and succulent collection! 

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