Houseplant · Aizoaceae
Lithops
Lithops
Tiny living stones, smooth and fleshy, that drink almost no water and split themselves open to grow.
Full sun
41–77°F · 5–25°C
USDA 10–11
1–2 in · 2–4 cm
Overview
Up close, a lithops reads as two fat, fused leaves pressed together into a single squat body, its top sliced by a narrow fissure down the middle so it looks like a cleft pebble. The surface is smooth and firm to the touch, patterned in muted stone colors, greys, browns, coppers, and dusky pinks, often netted or dappled so it truly passes for a rock. Set into a clear window across the flat top, faintly translucent, is a pane that lets light sink into the leaf and reach the tissue below.
Each plant is small and full of stored water, seldom more than 2 inches (5 cm) across, its flesh so plump the body feels taut and slightly yielding. The real spectacle comes with renewal: a fresh leaf pair swells inside the old one and forces it apart, drawing the outer pair dry until it collapses into a papery husk wrapped around the new growth. From the fissure at the top, in late summer and autumn, a single daisy-like flower opens, white or yellow, its slender petals fanning wide from the very center of the stone.
The colors and markings shift from one plant to the next, no two quite alike, which is a large part of the appeal. Beneath the stony surface sits a soft, water-filled interior built to ride out drought, and the whole small body works as a living reservoir. Keep the watering true to its cycle and that stone-like form holds its shape and pattern for decades.
Care
The short version: give them the brightest sun you have, pot them in a sharply draining gritty mix, and water only during active growth in autumn and spring while keeping them completely dry through summer dormancy and the leaf split.
Light
Lithops need full sun or the brightest light you can give them, year-round, with a south-facing window ideal indoors. Skimp on light and the firm, flat-topped bodies stretch tall and fade to a soft pale instead of holding their squat, stone-like shape.
Water
This is where most lithops are won or lost. Water only during active growth in autumn and spring, soaking the gritty soil and then letting it dry out completely before the next drink. Through summer dormancy and the leaf split, keep the fleshy bodies bone dry, since water at the wrong moment rots them fast.
Soil
Plant them in a very gritty, sharply drained mineral or cactus mix that water runs straight through, at a pH anywhere from 6.0 to 7.5. The faster the coarse soil dries around the base, the safer the plant.
Temperature
They handle a wide range, from about 41°F to 77°F (5°C to 25°C). A cool, dry winter rest suits them, but shield the tender bodies from hard frost and from baking heat that would force them to drink when they shouldn't.
Humidity
These are desert plants that want low humidity and moving air, so there is no figure to chase. Damp, stagnant air only softens the surface and invites the rot that kills them.
Feeding
Lithops barely need feeding. A dilute, low-nitrogen, high-potassium cactus fertilizer during the autumn and spring growth is plenty, and even that is optional. Too much food swells soft, weak flesh.
Pruning
There is nothing to cut. When the old leaf pair shrivels to a husk during renewal, let it dry and be absorbed on its own, and resist peeling or pulling it off, which only tears at the new body and sets the plant back.
Repotting
Repot only every 3 to 5 years, and only once the clump has crowded its pot or pushed roots out the drainage holes. The little stony bodies like a snug container, so there is no rush to move them.
Size & spacing
Each plant stays tiny, just 1 to 2 inches (2 to 5 cm) tall and about as wide, the squat bodies slowly gathering into a clump over years. A small, shallow pot holds several stones with room to spread.
Troubleshooting
Almost every lithops problem traces back to water and light, and most of it is preventable. The plant shows its trouble in the body itself, softening, stretching tall, or puckering into wrinkles, so learn to read those changes in the flesh against where it sits in its yearly cycle. Match what you see below before you reach for the watering can.
Flesh gone jelly-soft and translucent, sagging into the soil
When the firm, stony body turns soft and see-through, glassy where it should be solid, that is rot taking hold. It nearly always follows water given at the wrong time, whether through summer dormancy, during the leaf split, or in soil that stays damp against the base. Stop watering, cut the collapsed, discolored tissue away with a clean blade, and set what remains into dry, gritty mix until the surface firms up again.
Fix:
- Stop watering immediately
- Remove the plant and cut away any rotted tissue with a clean blade
- Repot into dry, gritty mineral mix and withhold water until firm growth resumes
A pale column stretching upward as the flat pebble shape disappears
A body that pushes upward and fades to a washed-out pale, losing the low, flat-topped shape, is starved of light. That squat, pebble-like form only holds under strong sun. Move it to the brightest window, and raise the light in stages so the tender surface does not scorch under the sudden brightness.
Fix:
- Move to the brightest available position
- Introduce stronger light gradually to avoid scorch
A stack of old and fresh leaf pairs wedged one atop another
When the shriveled old leaves stay clamped around a fresh pair pushing up between them, the plant has taken water during its leaf split. The new bodies are built to drink from the withering old pair, drawing it dry, not from the soil. Hold back every drop and let the old leaves collapse to papery husks and be absorbed.
Fix:
- Withhold all water until the old leaf pair fully dries and is absorbed
Puckered, wrinkled skin across the body during the autumn or spring flush
When the smooth, taut surface puckers into fine wrinkles during the growing months, the plant is simply thirsty, and a careful drink swells it back to its plump, rounded form. Timing is the whole of it. The same wrinkling through summer dormancy or renewal is a natural drawing-down and should be left alone.
Fix:
- Resume careful watering only if the plant is in active growth
Toxicity
Good news for homes with pets or small children: lithops are non-toxic across the board. Cats, dogs, rabbits, birds, and people can all share a space with them safely. The fleshy leaves hold no harmful compounds, so a stray bite into the firm body is nothing to worry about.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats face no poison from it. A bite into the firm, fleshy body does no harm, though a mouthful of the coarse gritty mix can bring on a brief bout of vomiting, and that is the soil rather than the plant.
Dogs None
A dog that crunches one of the little stony bodies comes to no harm, since it holds no toxic compounds. Its low, squat shape rarely tempts them anyway.
Horses Safe
Nothing in the plant is poisonous to horses, and a body barely wider than a pebble offers almost nothing to graze.
Rabbits Safe
Rabbits can sample the plump, fleshy leaves without risk, since they carry no harmful compounds.
Livestock Safe
Cattle, goats, and sheep meet no toxic threat from it, and a succulent this small, no larger than a stone, seldom crosses their path.
Birds Safe
Pet birds can peck at the smooth surface freely, since the plant holds no toxins to trouble them.
People Safe
The plant is harmless to people, children included. It is not grown to eat, but a curious taste of the firm flesh does no damage.
Varieties
The genus holds dozens of species, prized for the colors and surface markings that play across their windowed tops. A few turn up again and again in collections.
Lithops aucampiae
One of the easier species to grow, its tops a warm reddish-brown to copper crossed by darker, branching lines.
Lithops lesliei
A widely grown species with finely netted, rusty-brown windowed tops and yellow flowers.
Lithops optica 'Rubra'
A collector's favorite whose bodies burn a deep, striking purple-red.
Lithops karasmontana
Its pale grey to pinkish bodies are traced with an intricate reddish pattern spread across the surface.
Lithops salicola
Grey-green tops set with translucent windows, and it shrugs off a touch more moisture than most of its relatives.
How to propagate
You can raise more lithops from seed or by splitting an older clump, and neither is quick. Both ask for patience and a light hand with water.
SeedModerate
Sow in spring or early autumn onto gritty mix and keep warm and lightly moist until germination. · 2 to 3 years to reach mature flowering size
Most lithops start as tiny seed, scattered over gritty mix in spring or early autumn and kept warm and lightly moist until minuscule green bodies break the surface. It rewards patience, since a seedling needs 2 to 3 years to swell to mature flowering size and a careful hand with moisture the whole way.
DivisionModerate
Divide established multi-headed clumps at repotting during active growth. · Several months to root and re-establish
Older clumps that have thickened into several heads can be split during active growth, usually at repotting. Cut cleanly between the fleshy heads so each keeps its roots, let the pale cut faces dry over, then pot them up and give them several months to root and re-establish.
Myths
Lithops are a type of cactus.
They are leaf succulents in the family Aizoaceae, unrelated to the true cacti of the Cactaceae despite the stony, spineless look. The two groups landed on the same water-storing form from separate branches of the plant world.
Lithops like their soil kept moist on an ordinary houseplant rhythm.
Watering them like a leafy windowsill plant is what kills most of them. The stony bodies must stay completely dry through summer dormancy and the leaf split, and overwatering is the single most common cause of death.