Pleiospilos Nelii, or also labeled as Split Rock, Living Rock Cactus, Cleft Stone, or Mimicry Plant, is an eye-catching flowering succulent native to South Africa. This plant doesn’t grow more than a few inches in height and has two to four gray-green stone-looking leaves that are separated by a cleft down the center.
Growing Split Rock is not that hard. In fact, they are low maintenance, which makes them a wonderful decorative houseplant, especially with their very interesting hues and shapes. You just need to figure out the right balance of their needs to thrive.
Read on to find out more.
Growing cycle and Watering
Like most succulents, Split Rocks are drought tolerant, allowing it to survive long periods without water, making it the ideal plant for someone with a very busy schedule.
Ideally, this should be given a good soak of water whenever the soil has completely dried out in between watering during its growing season, which usually happens in Spring and early Fall. In Summer and Winter, where extreme temperatures are present, your watering routine should be reduced significantly to once every few weeks.
Bear in mind that overwatering can cause the Split Rock to crack and eventually rot. So make sure to check the soil first and the hardness of the leaves before watering again. If you feel that the soil is almost dry, but the leaves are still solid, this means that they don't need to be watered yet.
Also, keep in mind that a healthy and happy Split Rock often only have two sets of leaves at a time. Once your plant is starting to develop more than two sets or even show the slightest cracking on its epidermis, it's an indication that you are already drowning it. So as soon as you see these signs on your Split Rock, avoid watering it for at least a week.
Light + Temperature
When it comes to light exposure, Split Rocks need partial shade to full sun to grow happy and healthy. So if you are growing it indoors, you should expose this plant to as much light as possible to flourish, especially during Winter, as cold temperatures tend may affect the plant’s general well-being. A spot near a south-facing window should meet this condition. If you don’t have a south-facing window or any spot where your Split Rock can get enough light, consider getting some grow lights.
You can also grow your Split Rock in your garden outdoors to enjoy bright light, but make sure to keep it protected against the harsh sun in the afternoon and rain. Also, keep in mind this plant is not cold hardy. So if you live in a zone where it gets colder than 30 degrees Fahrenheit, we highly recommend growing it in a container or pot where they can easily be brought inside as soon as the temperature starts dropping.
Soil and Pot
As a succulent, Split Rock needs well-draining soil as well. You can meet this condition by blending a 25% cactus mix and 75% pumice. And since split rock has a long taproot, the pot size should be at least 3.5 to 4-inches deep with a hole in the bottom for proper drainage. This will lessen the risk of risking your plant to get root rot problems.
Since Split Rocks are slow growers, repotting should only happen once every 3 to 5 years. To do this, simply select a new plant to transfer your plant that’s around 4-inches deep with a hole at the bottom. This should provide proper drainage to your Split Rock and allow its roots enough space to grow.
You may also plant your Split Rocks on the ground in your outdoor garden. Just make sure that the soil you’ll use and draining conditions are optimal to avoid rot due to improper drainage or freezing. Your plant will also appreciate it if you are to add some rocks on top of its soil, as this will let them feel at home. Also, make sure to cover at least ⅓ of its stem in the soil, leaving ⅔, just like the way a rock would sit on the ground.
Once you have successfully transplanted your Split Rock, it is important not to give it any water for at least a few days to a week to encourage its roots to grow and adjust to its new soil. After a week, you may water, but only as needed.
Moreover, make sure not to disturb or repot your Split Rock while it’s still in the dormant period. Instead, do this before the plant starts its blooming cycle, which usually happens in early Spring.
Growing New leaves
Every late Spring or early Summer, Split Rock grows new pairs of leaves in the center to replace the old ones. So if your Split Rock starts to produce more than one pair of leaves or whenever your plant becomes wrinkled and a little soft, cut off with your watering. This should enable your plant to use its stored water, allowing the outer pair of leaves will dry out, shrink and disappear, as they will be used by the plant as a nutrient to support its new growth.
During Spring, Split Rocks also produce some spectacular flowers with coconut-like smell from the crack or cleft. These flowers may come in yellow, orange, white, or magenta colors and is usually a little larger than the plant itself.
Like Lithops, Split Rocks may also bloom flowers in Autumn. However, Lithops can only produce one flower at a time. Split Rock, on the other hand, has the ability to produce more than one in just one blooming cycle.
While these 2 plants are quite similar, you may easily differentiate them from one another, as Lithops are smaller than Split Rock and do not grow when buried in the ground.
As Split Rocks have the capability to take care of its own, it doesn’t require grooming at all. However, if you see that the old leaves were not completely absorbed by the plant, you can remove it. But only if you feel that can easily come off. In other words, if the leaves are still firmly attached to the rest of the plant, give it more time to shed the leaves itself, to avoid hurting or damaging the plant.