Lithops: Growing Unusual Living Stone Plants
Contents
Have you ever been browsing in the succulent section of a garden center and discovered a pot with nothing more than a pair of flat-topped split rocks in it? If so, you may have discovered the lithops plant, an unusual African genus of succulent.
Sometimes called split rocks or pebble plants, lithops living stone plants are extremely drought-resistant and are widely popular in low-water gardens in desert regions. They can be grown both indoors and outdoors, but outdoor growers should be careful that they don’t get too much water.
The term lithops is both singular and plural, so don’t go searching for a lithop… always look for lithops succulents. But this plant is easy and fun, and definitely something different to mix into your succulent garden!
Subscribe to the Epic Gardening Podcast on iTunes or Spotify
Good Products At Amazon For Growing Lithops:
Lithops Overview
Common Name | Lithops plants, living stones, living stone plant, split rocks, split rock plant, pebble plant, flowering stones |
Scientific Name | Lithops aucampiae, Lithops dorotheae, Lithops fulviceps, Lithops hookeri, Lithops karasmontana, Lithops lesliei, Lithops localis, Lithops optica, Lithops pseudotruncatella, Lithops ruschiorum, Lithops salicola, Lithops verruculosa, Lithops viridis and other lithops species |
Family | Aizoaceae |
Light | Full sun to partial shade |
Water | Extremely light to none at all |
Temperature | 65-80 degrees optimal, can take heat to 90-100, do not go below 50 degrees |
Humidity | Tolerant of short bursts of humidity |
Soil | Gritty or rocky, sandy soils; extremely well draining soil preferred |
Fertilizer | None to extremely light high-phosphorous |
Pests | Spider mites most common. Can also attract thrips, scale insects, mealybugs, aphids, snails, slugs, and root knot nematodes. Mice and other small animals may eat it for its water content. |
Diseases | Almost none, but can develop rot if overwatered, exposed to cold conditions, or damaged |
All About Lithops
Lithops plants are fascinating little succulents. The living stone or flowering stones plant is very sensitive to the extreme seasons of the year, but can live for decades. Further, many species flower in the fall, which can be a great burst of light color amidst all the oranges and reds of the growing season.
Let’s explore the life cycle of the lithops succulent plant in more detail now, and then go over some of the most common varieties.
Lithops Lifecycle
When one looks at lithops plants, all that’s visible above the ground’s surface is usually a pair of fleshy, succulent leaves that look like flowering stones, with a crevice between them. The majority of the plant is beneath the soil surface.
These succulents have window-like cells on the leaf surfaces that allow light deep into the plant to aid in photosynthesis. The main taproot is the most important for the plant’s survival, but a series of finer roots also helps draw in extra nutrition when needed.
Lithops succulents flower in the late autumn or early winter generally, although some species flower in the spring or early summer. A single flower will be pushed up from the crevice between the pair of leaves. However, only plants older than 3 years (and sometimes 5 years) will produce flowers.
The lithops flower is daisy-like in appearance, and depending on the species can be anywhere from a half-inch to an inch and a half in diameter. It can be orange, white, or pale yellow. Some have a scent which is described as spicy-sweet.
These flowers will open in the early afternoon to soak in sunlight and allow for pollination, and then will close in the late afternoon before dusk. As lithops is not self-pollinating, they are reliant on insect pollinators or humans to produce seed.
When the lithops flower fades, the center forms a seed capsule. This capsule does not open unless it’s been moistened, but once it does, rain droplets can cause seeds to bounce out of the capsule and land up to a foot away from the parent plant.
As the lithops seed capsule dries again, it will naturally close to protect any remaining seeds inside. If you are trying to harvest lithops seeds, you can simulate rain by using a dropper to drip water on the seed capsule until it reopens and then remove the fine seeds.
After flowering has concluded, the plant will go dormant. During this time, it starts to form a new body. When it begins to grow again, the new leaf pair will emerge from the crevice between the old leaves.
Over time, the plant will draw its moisture and nutrients from the old leaves, transferring it to the new pair. The older leaves will thin out. Once they’ve become paper-thin and are devoid of their moisture, they can be removed to reveal the new plant body.
Lithops may grow in size by creating two leaf pairs instead of a single pair, and can gradually expand to become a clump of small plants.
Types of Lithops
It’s estimated that there are at least 37 species of lithops, and around 145 varieties. More varieties are regularly discovered or bred by hybridization and are shipped bare root. If you don’t know where to start, try a lithops starter pack!
While we’re not going to cover every possible lithops species today, here’s some of the most popular houseplant varieties.
Lithops aucampiae
Named after Juanita Aucamp, the woman who discovered this species, Lithops aucampiae’s native habitat originates in South Africa. It naturally grows in sandstone, chert, quartzite and ironstone-based soils, but can be grown in most sandy, extremely well-draining soils.
Most of this species of living stones tends to be in the red to red-brown range colorwise, and they produce yellow or white flowers. It is one of the species which most tolerates occasional incorrect watering, making it extremely popular amongst gardeners.
Lithops dorotheae
Another species from Southern Africa, this one was discovered by Dorothea Huyssteen, leading to its naming. Naturally growing lithops on feldspar, sheared quartz and quartzite, it can adapt to other grit-filled soils as well.
This species has a creamy pale green coloring with a brown or darker green leaf surface, mottled with cream-colored speckles. It produces a yellow flower annually.
Lithops fulviceps
Originating in Namibia, lithops fulviceps prefers rocky areas and cold desert regions. It naturally prefers quartzite-heavy environments, although it can live on limestone slopes too.
In coloration, the sides of the leaves are a greyish-green or yellowish hue with orange, brown, green, and sometimes cream-colored mottled upper surfaces. The leaf shapes are very similar to kidney beans as they divide to flower, but form a neat oval when not flowering.
Lithops fulviceps produces a white or yellow flower depending on the cultivar.
Lithops hookeri
Preferring quartzite and lava rock to grow on with some limestone, lithops hookeri is another South African stone plant with a marked stone like appearance. It can grow quite large for a pebble plant with leaf sizes nearing 2″ across at their widest point. Normally growing singly, it can form clumps of up to 10 pairs off leaves.
The upper surface of its leaves can range from brownish to red or pink tones, occasionally picking up bits of orange. The sides of the leaves are often a dull grey or greyish-brown, almost terracotta tone. Its flowers are usually bright yellow.
Lithops karasmontana, ‘Karas Mountains Living Stone’
Depending on species, lithops karasmontana will either mimic the grey and brown hues of local quartzite stones, or will develop a brilliant red-orange upper leaf in some varieties like var. laricheana. The sides are uniformly grey with a tinge of brown.
Its name refers to the Karas Mountains in its native Namibia, but it can also be found in South Africa proper. It produces a brilliant white flower with a yellow center.
Lithops lesliei, “Lesliei Living Stone’
Found naturally in Botswana and parts of South Africa, the lesliei lithops plant is the only lithops-type plant found in its natural environment. The species is incredibly variable in terms of color, ranging from pale green all the way to a rust or coffee coloration on the leaves.
It often camouflages itself to match the color of the soil around it, making it difficult to see, and it rarely rises more than a couple milimeters above the soil’s surface to further disguise itself. The yellow-flowered plants are often harvested for medicinal use in South Africa.
Lithops localis, ‘Lithops terricolor’
A species which can tolerate a poor watering schedule or inconsistent habits, lithops localis tends to be a uniform grey or green-grey color across most of its surface, giving it quite a stone like appearance. Speckles of a darker grey hue dapple the flat top of the leaves.
Indigenous to the southern Karoo region of South Africa, split rocks often grows amongst other rocks and shading shrubs as a way to disguise itself from animals that might eat it. Its natural environment gets most of its rainfall during the summer months, and thus it tends to flower in the fall.
Lithops optica
Another Namibian species, lithops optica lives in an area which gets winter rainfall, making it one of the few varieties adapted to winter watering. The most popular variety of this plant is Lithops optica var. rubra, which is purplish-pink across its entire surface.
The thin-petaled flowers tend to be yellow or white and have very slender petals. While the Rubra variety is brilliantly colored, most other optica species plants tend to be grey to grey-brown in coloration, with a very rounded shape.
Lithops pseudotruncatella, ‘Truncate Living Stone’
From southwestern Africa, the truncate living stone is very distinctive. Its exterior leaf walls tend towards an even grey tone, but the upper leaf surfaces are dappled with cream, olive green, and rust hues.
One of the few species regularly subject to mealybug attack, this plant is otherwise a sturdy and long-lasting species of lithops. In its natural environment, it often lasts for months without any water, simply absorbing moisture from the air around it.
Lithops ruschiorum
Off-white, grey, or tan in coloration, this particular plant looks very much like a living rock. Some varieties are a pure cream color, where others range between tan or grey with darker stone-like streaking.
Namibia is home to this cultivar as well, and it lives most often in cold deserts or rocky regions in the wild.
Lithops salicola, ‘Salt-Dwelling Living Stone’
The salt-dwelling living stone takes its name from the mineral-rich environment in which it naturally occurs. It can be found in both Namibia and South Africa and is somewhat tolerant of incorrect watering practices.
While it can’t tolerate freezes, the grey to grey-green leaves are more tolerant of dry, cool temperatures than some. It produces a bright white or yellow flower in the late summer to early fall. Royal Horticultural Society has given this species the Award of Garden Merit.
Lithops verruculosa
One of the more recognizable species, these flowering stones often develop distinctive red warts on their surface. Different cultivars can take on different colorations ranging from reddish in hue to a gray-green tone with the red warting.
The “Rose of Texas” variety produces pink-tinged flowers, where other verruculosa species produce white or yellow flowers. It has a natural habitat originating in Southern Africa.
Lithops viridis, ‘Green-Rock Plant’
The green-rock plant has a natural habitat that originates in a very small portion of the Northern Cape area of South Africa, and is extremely uniform in coloration. The sides are greyish-pink, grey-green, or pure grey with an upper surface that is a dark grey-green tone.
Producing yellow flowers with yellow or white centers, lithops viridis is often only seen in cultivation in botanical gardens. The more greenish specimens are some of the most prized, as they look like pale green-grey nubs rising from the gritty soil.
Lithops Care
For the most part, growing lithops is a very hands-off process. They handle themselves quite well! But there’s a few things about how to care for a lithops plant that you’ll need to know.
Light
In its natural environment, lithops is a full-sun plant. Flowering stones require enough sunlight to produce their colorful stone-like display.
However, in gardens or as houseplants, 4-5 hours of direct sunlight per day should be enough to keep your plant happy. Some partial shade is just fine.
In coastal regions or where the temperatures are cooler, you may be able to leave it in direct sun all day long. Those who live in desert conditions or areas where it reaches excessive heat will want to place their plants where they’ll receive indirect light and some afternoon shade to cool off.
Not growing your lithops outside? Be sure it gets enough direct sunlight every day and that you regularly rotate your plant. Etiolation, an elongation or warping of the leaves, can happen if your plant isn’t getting enough sun. It’ll stretch out its leaves to try to get the most light it can.
Color loss can also become problematic if your plant gets too little direct sunlight. Usually, a south or west-facing window will get your plant enough sunlight to thrive, but you’ll want to regularly turn it so that the whole plant gets some sun.
If your plant is indoors and was in lower-light conditions over the winter months, slowly re-adapt your lithops to longer periods of light in the spring by gradually increasing its full sun exposure. This will prevent scarring or sunburn on the leaves.
Plants in warm climates (regions where it doesn’t drop below 50 degrees) can remain outdoors all winter long and will not need gradual exposure.
Temperature
The South African regions like Namibia, where the natural habitat of lithops originates, rarely experience frost conditions. This means that the plant itself has never adapted to colder temperatures, and it really, really doesn’t like the cold.
Prevent exposure to frost or freezes because the cell walls in the thick leaves will rupture if it’s too cold. This will cause your plant to rot and die. Ideally, don’t allow your lithops to remain in conditions below 50 degrees Fahrenheit, and never leave it outside below 40 degrees.
While the optimal growing season for lithops involves temperatures between 65-80 degrees, these desert plants can tolerate intense heat and temperatures up into the 90s and 100s for short periods. However, they should be exposed to morning sun and afternoon shade in these conditions.
Water
The most difficult part of lithops care is watering because the plant is from an area of extreme drought. Less than an inch of water in a year is not unknown in its natural environment. The plant has adjusted to a life of water conservation in arid regions.
Almost the entire plant is devoted to storing water to sustain itself. Those fleshy, rock-like leaves are basically water tanks for the plant’s survival!
Because of this, you need to water according to the time of year because the plant has distinct seasonal habits.
Spring and fall are the plant’s normal growing season and when it’s most likely to need water. During those seasons, limit your watering to once every ten days or less. Do not water unless the soil has completely dried out to four or five inches below the surface.
If your plant seems happy without water during the spring and fall, don’t water it. Chances are that it’s getting enough moisture from the humidity in the air. Many species of lithops draw the majority of their moisture from dew or humid air.
Rain exposure should be greatly limited, even in well-drained soil. As I mentioned, these plants are not accustomed to having much water, and too much will cause decay in the plant!
During the summertime, we’re all used to watering our plants more often. However, living stones go dormant during the summer heat. During summer dormancy, it’s important to only water them if the plant is becoming wrinkled and looking as though the leaves are drying out.
If you do water during summertime, do it in the early morning, and give only a tiny bit of water to the area where your lithops grow. The smallest amount should provide ample moisture for the leaves to plump back up and the plant to become good as new.
Avoid watering during the winter entirely. Your plant will be in semi-dormancy, although sometimes a flower may linger into the early part of the winter months.
This is a plant that is incredibly easy to overwater. Err on the side of underwatering, and your lithops will be quite happy.
Soil
A well-draining, grit-rich cactus mix of potting mix is ideal for most lithops plants. Their natural habitats range from sand to decomposed granite and rarely hold on to much water.
Don’t have access to a cactus mix? Don’t panic. Make your own by mixing 50% potting soil or compost with 50% grit material. Good options include pumice or lava rock, sand, decomposed granite, perlite, or other gritty materials which make for well-draining soil.
Soils that hold too much moisture can cause your lithops to develop root rot or can spur the development of pests that can attack the roots. Since their natural environment is quite harsh, they tolerate poor soil a lot better than rich soils, so err on the side of gritty or sandy potting mix.
Fertilizer
As a general rule, fertilizing your lithops isn’t needed. These plants get almost no fertilizer in their natural habitats, like most other succulents.
However, some people do offer their living stone plant a little burst of fertilizer just prior to its normal blooming season to encourage flowering. If you opt to do that, use a heavily-diluted cactus fertilizer, one which is low-nitrogen, high-potassium in formulation.
Just like watering, you want to fertilize sparingly, if at all. And avoid foliar fertilization, as it can cause sunburn on the leaves.
Propagation
Most people propagate lithops from seed. To do this, you simply prepare a pot of soil as described above, carefully sprinkle your lithops seed over the surface, and cover with a fine layer of sand. Keep the sand lightly moist until germination occurs, and gradually reduce watering for your baby seedlings. Your lithops seedling size will reach .3 to .5 inches in about 12 months.
These plants can also be propagated by division of a parent plant. If you have a cluster of plants, you can carefully remove it from its pot, gently dusting off the soil around the roots. Examine the root and leaves to decide where to cut, then use a sterile razor blade to neatly remove the leaf pair with a good amount of taproot still attached.
Including any of the other finer feeder roots is less essential, as these will quickly regrow. But your lithops leaf pair will require some of the taproot to survive.
Once separated, repot as directed below.
Repotting
Unless you’re dividing your plant, you may find that repotting is rare. Lithops can live for 40 to 50 years, and it’s not uncommon for someone to have their plant in the same pot for 10-20 years!
The most common reason to repot is to divide the plant if your plants start to take over the entire pot. Otherwise, you may want to place their lithops in a larger pot to develop a larger colony of plants.
Regardless of why you’re repotting, you will need a pot that’s deep enough to handle the long taproot. A minimum of 3″ is required, but 5″ or even slightly deeper is better. This allows the taproot to grow without coiling around the pot.
Prepare a well-draining cactus potting soil, and plant your living stone plant with its leaf tops slightly above the soil’s surface. About a half-inch above the soil is fine. Be cautious with the root structure, as the taproot is essential to your plant’s survival.
Once repotted, you can place gravel or rocks around the soil surface to simulate the split rocks plant’s natural environment. Avoid transplanting it for at least another 3-4 years, and if it was a division, wait even longer.
Pruning…?
Nope! Living stones or split rocks don’t need pruning. Since only two leaves are visible above the soil level, the plant will take care of itself.
At the most, you may rarely have to remove the papery remnants of older leaves of split rocks once the plants start to reabsorb all of their moisture and nutrients. Even then, the new leaves will spring up from the older ones, and eventually the older leaves will slough off on their own.
Lithops Problems
On the whole, the majority of problems with the living stone plant or split rocks come from overwatering. However, a few pests may be tempted by the juicy leaves, and there are a few other issues that might strike your plant. Here’s how to deal with those!
Growing Problems
Etiolation is a term that refers to a plant basically stretching and warping to reach sunlight. The living stones are prone to etiolation, and instead of lying flat against the surface of their soil, they will rise above it and bend or twist so that the tops of the leaves are angled to the sun.
If your plant appears to be suffering from etiolation, it needs more consistent direct sunlight. Gradually reintroduce your plant to more light, trying to ensure that the entire plant gets regular light. During its next dormancy cycle, the new growth should form against the soil level again.
Dessication or wrinkling of the split rocks leaves can occur when your plant gets thirsty. If it starts to develop a raisin-like surface, you need to give your plant a drink, and it should re-plump itself up within a day or two. At the same time, avoid over watering as excess water can be a problem, too.
Scrapes to the leaf surfaces can cause brownish or whitish scars that look very similar to a scratch on human skin. These scars will remain until the plant has developed a new leaf pair, and then those leaves wither away as the old leaves’ moisture is reabsorbed into the plant.
Pests
Most pests are likely to ignore lithops the majority of the time. However, a handful can act to damage your plant if the opportunity presents itself.
Spider mites are the most likely problem of lithops growers. Most often they will live in the crevice between split rocks leaves, or hidden between an old leaf and a new one. They cause white spots of scar tissue on the plant’s surface, and they thrive in dry environments. If they’re left to feed on your plant, they can make the leaves wither.
If you encounter spider mites on your plant, consider using a product like neem oil along the sides and in the center crevice of the plant. The mites rarely attack the upper surface of the leaves, so this should be enough to protect it. A fine mist is all that’s required, don’t soak the plant!
There are a few other pests that can attack your plant, but these are opportunistic pests. They prefer other plants as a general rule, but if your living stones make an appealing target, they may strike. Here’s a short list:
- Thrips. If your pebble plants are shedding older leaves, thrips can live between the older thinning leaves and new ones. They can cause dark scarring to the newer leaves. Use insecticidal soap to eliminate these on your lithops and other surrounding plants.
- Scale Insects or Mealybugs. Mealybugs are a form of scale insect, and both regular scale and mealybugs will attack many cacti and succulent plants. Gently scrape them off if found, and apply insecticidal soap to the plant’s exposed surfaces.
- Aphids. Cactus aphids may be lured to your lithops and its juicy leaves. Again, insecticidal soap should eliminate these pests.
- Snails and Slugs. If growing your living stones outdoors, grazing animals like snails and slugs may cause damage to the leaves. Use bait to draw them away from your succulent garden.
- Root Knot Nematodes. While these often will not cause severe damage, the microscopic soil-dwellers can make the roots of your lithops warp and twist. They often do not survive well in drier soils, so use a well-draining, grit-rich soil to keep them at bay.
- Mice. Surprisingly, mice find lithops plants to be attractive food sources, and they can chew away large portions of your plants if you’re not careful. Use good mouse traps to keep them out of your house, and consider placing a fine mesh cloche over potted outdoor specimens.
Generally, the only pest that most people will ever see on their lithops is spider mites, because the optimal conditions for other pests aren’t usually met. But in the rare circumstance that other pests appear, now you know how to deal with them!
Diseases
The vast majority of plant diseases have little to no impact on lithops. Since they grow in sandier soils, they are not subject to most soilborne fungal diseases, and they do not typically develop powdery mildew or other above-ground fungal diseases.
However, they are susceptible to rots caused by overwatering or damage to the leaves. An excess of water can cause the fleshy leaves to swell and crack or burst, leaving them open to bacterial infection. Scrapes or cuts on the leaves can also leave them at risk.
Generally, as long as you are careful about not scratching your pebble plants and limit your watering to only when it’s most necessary, you will not experience any plant diseases.
As I mentioned earlier, cold temperatures at 40 degrees or less can also cause your lithops to rot. This is a slightly different form of rot, and is caused by the water-filled cells of the plant bursting inside the plant’s skin. Avoid exposing your plant to colder temperatures to prevent this.
Frequently Asked Questions
Q: Are lithops hard to grow?
A: Not at all! They are slow-growing, but are very easy to care for.
Q: How often should you water lithops?
A: Very rarely. Usually, the best indication that your lithops plant is thirsty is it becoming wrinkled. Those fleshy leaves are like water storage bladders, and wrinkling indicates they aren’t as full of water as they could be.
Q: Do lithops split every year?
A: Yes, this is normal. What most people are experiencing is the process of lithops forming new leaf pairs. In the process, the old layers are shed, much like a snake sheds its skin – but it looks strange!
Q: What do overwatered lithops look like?
A: Yellowing is a sure sign of an overwatered lithops. In addition, a mushy texture may mean that it’s starting to rot, a common issue if it’s been overwatered for too long. Finally, edema, or a blistered, brown patch, can form when it’s had too much water.
Q: What is Blue Witchford lithops?
A: There are a number of unusually-colored plant seeds sold online (often from China), and Blue Witchford lithops is one of those. In most cases, these are fakes.
In the case of “Blue Witchford lithops,” it’s believed that the images shown online of it are heavily photoshopped. In fact, they aren’t even of a lithops plant at all – they’re images of Pinguicula esseriana that have been colorized blue to sell seeds by scammers. Purchase seeds from reliable seed companies to prevent disappointment!
Q: Are lithops poisonous?
A: There are reports of people in Namibia chewing on a lithops plant to extract the moisture, and the ASPCA has it marked down as non-toxic to dogs or cats. So the lithops plant itself may not be toxic.
Whether or not it tastes good may be a different matter. The flowers themselves can smell spicy-sweet, but there are few reports as to the flavor of the leaves, suggesting it’s not an ideal food source. Still, they should not be poisonous.
If you are concerned, it’s best to check with your doctor or veterinarian. Better to be safe than sorry!