They are native to southern Africa, where they generally receive less than an inch of rain per year. Their water needs are met by pre-dawn fog. Once the fog burns off as the sun rises, there is no further water for the rest of the day. This makes them the ultimate in xeric plants, and a great plant choice for those who tend to neglect their plants. They also make a great conversation starter if you are looking for a centerpiece plant for your collection.
There are two distinguishing forms of mesemb: leaf pairs on a taproot such as a Lithops of Pleiospilos, or a colony of flat-topped leaves on a taproot or caudex such as a Fenestraria or Frithia. While there are other plants in the Aizoaceae family, my view is that more it looks like a "typical" succulent, the less it falls under the class of being a living stone. If it has pointy leaf shapes, or is forming rosettes, or long stems with multiple alternating leaves, it is not a mesemb.
Potting up your mesemb
Pot up your mesemb in a mixture of rocks such as granite, lava rock, or small gravel. Mix just a small amount of cactus potting mix in the pot with the rocks.
Plant your mesemb about half an inch above the potting mix surface, then add a topdressing to mimic its nature rocky environment.
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| source pic: gardenmanage.com |
The best time to repot a mesemb is during the growing seasons (spring and autumn). Provide a small amount of water to a newly repotted mesemb.
Warning:Mesemb have very specific needs. They do not do well when potted with other succulents (or really, any other type of plant). They are unsuitable for a mixed-plant container display.
Watering your mesemb
Mesemb require very little water. In fact, they should only be watered once or twice a year. How do you know when they need water?
Is it summer or winter? Don't water them. They are either dormant or the old leaves are drying out as the plant grows. Remove the dead leaves and give the plants a bit of water when they are ready.
Is it autumn or spring? If they show signs of producing a flower, give them a bit of water to help it along.
In short, if you are not sure if they need water, they probably don't. Ignore them. They thrive on neglect. They are the perfect low-maintenance plant!
If you wish to emulate their native environment, place them in a bathroom where they can absorb the humidity from morning showers. Once that dissipates, they will be dry the rest of the day with no need for direct watering.
Fertilizer for your mesemb
Like most succulents, no fertilizer is required for an established plant. Fertilize young plants only when watering. A dilute fertilizer is best. I use a dilute solution of gentle fertilizer meant for epiphytes.
Lighting for your mesemb
Mesembs love a full sun environment. They want direct light, and lots of it! Outdoors would be best unless you are in a damp climate. A south facing window is ideal if you are growing them indoors, however.
Propagation of your mesemb
Many mesembs cannot be propagated by leaf cuttings like so many other succulents. They need their leaves, and unless it is a type of mesemb that forms a colony, it is also rare for them to produce offsets which might allow for division.
The primary way to propagate a mesemb is by the seed collected when the plant flowers. However, mesembs are not self-fertile. Use a small paintbrush to transfer pollen from one flower to another. Once the flowers die back, there should be a seed pod remaining. Open the pod to collect the seeds.
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