It took about six dead Split Rocks (Pleiospilos nelii) in about as many years for me to get the hang of keeping one alive. The specimen in the photo is my first and only surviving Split Rock out of all those tries. It is thriving, and it even flowered in 2006. The flower was a pale yellow with an orangey tinge. This plant didn’t produce any flowers this past spring for some reason, but it’s definitely healthy and thriving. One sign of good care is a firm, round, symmetrical plant with no old leaves still attached at the end of summer.
The secret to keeping a Split Rock alive, I have learned, is to control the urge to water it all year long. I water this plant lightly in the fall for a couple of months and then again in early spring, and very seldom the rest of the time. In the winter, it grows new leaves from the center of the split, and the new leaves then consume the old leaves. If the plant is over watered, the old leaves remain and the plant usually rots and dies.
I took this photo today, and as you can see, there are no old leaves left at all, which means it received the proper amount of water in the summer. I watered the plant today, for the the first time in quite some time, now that fall is beginning. Even with no watering the leaves don't shrink and prune up like some succulents do when they are not watered. The Split Rock stays plump--even after months with no water.
The P. nelii is in the Aizoaceae family, but it is not in the Lithops genus, as some believe. Lithops are similar, and they are also in the Aizoaceae family, but they are a separate genus. The Pleiospilos genus, native to South Africa, contains well over 30 species, and as far as I know, all have various degrees of speckling on the leaves. I think the Split Rock has the most attractive markings of all of them. It's just cute, and I'm glad I've learned how to properly care for it.