Lithops or stone plants, are small stemless succulents that resemble stones to avoid being grazed by animals in their native habitat. They come from some of the driest regions of South Africa and therefore need very little water: some of them rely only on fog and mist to obtain the humidity necessary for survival.
Each lithops plant includes just two thick, fleshy, fused leaves, designed to hold the water the plant needs to survive. The leaves have a crack, or fissure, at the top, from which new leaves and flowers emerge. Because lithops require little water, they make excellent houseplants. The yellow or white, daisy-like flowers sometimes appear in summer.
These fascinating “living stones” are loved by succulent collectors for their unique appearance and ability to survive in extreme conditions. In nature they grow among the pebbles and sand of the desert, so much so that they are almost invisible: a perfect example of plant mimicry.
How to Care for Lithops
Lithops must be grown in a very draining soil, such as that for cacti, in a bright, sunny and dry place, such as a windowsill facing south or east. Water very sparingly, much less than other succulents. Do not water from October until the old pair of leaves have completely wilted, often until the following May. Then avoid watering again during the dormant period in summer.
Repotting Lithops should be done with extreme caution, every 3-4 years at most. It is important to choose a deep pot, preferably terracotta, which allows good ventilation of the roots. The ideal substrate is composed of 50% coarse sand, 25% pumice or perlite and 25% cactus soil. Avoid soils rich in peat, which retain too much moisture.
Where to place the Lithops
The lithops needs a sunny location: the aim is to get around five hours of direct sun a day, so a south or east-facing windowsill is ideal. Keep in mind that in winter you may need to remove the lithops from the windowsill if temperatures drop significantly.
How to water Lithops
Lithops have a very particular growth cycle and therefore need to be watered in a very particular way. The main consideration when watering lithops is the growth of new leaves. Lithops develop new leaves every year, which emerge from the gap between the two older leaves, which then gradually shrivel. The watering regime is based on the growth of these new leaves, if you water too soon after the new leaves appear, the old leaves may not wilt properly.
Unlike other succulents, lithops begin growing in the fall. In nature, this coincides with seasonal rains, so it is good to water the lithops in this period (early September). In this period the flowers begin to appear: observe the opening of the crack and the growth of a bud.
Lithops continue to grow throughout the winter and spring, with the new pair of leaves growing inside the old. However, it is important not to water the plant in winter, the new pair of leaves grows by drawing water from the old pair, so the soil must be very dry.
In spring, the old leaves shrivel and the new leaves are exposed, start watering again when the old pair of leaves are completely wilted. Water little at a time, allowing the soil to dry between waterings.
How to Propagate Lithops
You can propagate Lithops by division or by seed, although both options are time-consuming. To divide lithops you need to wait several years for the plants to develop into a cluster, then carefully remove the plant from its pot and cut the roots, ensuring that each part of the plant still has a viable taproot. Repot each division into a pot deep enough to allow the taproot to grow without being crushed.
To grow lithops from seed, prepare a pot with free-draining cactus potting soil and additional grit. Water the soil and let it drain, sprinkle the lithops seeds on the surface and cover with a thin layer of sand or vermiculite. Keep slightly moist until germination, then gradually reduce watering.
To encourage germination, cover the pot with transparent film or a plastic dome to maintain constant humidity, and place it in a bright place but not in direct sunlight. Lithops seeds can take 2 to 8 weeks to germinate.
Common problems
Too much water
Overwatering, or watering at the wrong time of year, is the main problem you can run into when growing lithops.
An over-watered Lithops normally shows signs such as;
When you notice these signs, quickly examine your Lithops to identify the problem, remove the damaged roots and clean them with a jet of water. Be sure to let the healthy part of the roots dry and disinfect before potting them with a new potting mix and a new container. Once this is done, it is best to change your watering routine to ensure that overwatering no longer occurs.
Etiolation
As with all other succulents, low light exposure can cause Lithops to elongate or etiolate. So, if you notice that the plant seems to be stretching, increase the light exposure. Keep in mind that to remedy an elongated or etiolated Lithops it will take a few growth cycles for your Lithops to return to its normal size.
Parasites and diseases
Again, overwatering Lithops can attract pests such as mites, thrips, mealybugs, mealybugs, aphids, snails, slugs and root knot nematodes. Additionally, mice and other small animals may attempt to eat this plant for its water content.
How to make Lithops flower?
As mentioned above, Lithops mostly require direct exposure to the sun, except for intense summer days. Even in contexts where outdoor cultivation is not practicable, providing them with 4-5 hours of direct sunlight per day is sufficient to promote luxuriant flowering even indoors.
The flowers are daisy-like, with shades of white, yellow and orange, often blooming in late autumn and early winter. Similar to a clover, they open early on sunny days, then close later in the day.
After flowering, the withered flower leaves a small capsule containing the seeds. This capsule opens only with humidity — a natural mechanism that ensures germination only in the presence of rain. You can collect the seeds and save them for propagation.
Are Lithops toxic?
Lithops are not considered toxic to humans and pets, in fact, according to some reports, African children eat these plants to quench their thirst. Be careful though, because they can be poisonous if chemicals, such as pesticides, have been sprayed on them. So it is better to be cautious and place this plant out of reach of children and pets to be safe.
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