Houseplant · Aizoaceae
Lithops
Lithops
Tiny living stones that thrive on almost no water, so the kindest thing you can do is leave them be.
Full sun
41–77°F · 5–25°C
USDA 10–11
1–2 in · 2–4 cm
Overview
At first glance a lithops looks like two smooth pebbles tucked into the soil, and that clever disguise is exactly how it survived the dry grasslands of southern Africa. Each little plant is really just two plump, water-filled leaves joined together, with a window on top that lets sunlight reach down inside. They stay small for their whole lives, seldom more than 2 inches (5 cm) across, yet with a light touch they can share your windowsill for decades.
The thing that makes them special is the yearly rhythm they follow, and once you see it, everything clicks. Across the hottest months they slip into dormancy and want no water whatsoever. Then a fresh leaf pair forms inside the old one, gently splits it open, and draws it dry, so the plant seems to remake itself from the inside out. Come late summer and autumn, a single daisy-like flower in white or yellow rises up from the seam between the leaves.
None of this is as hard as it sounds, and a lithops is far more forgiving than nervous growers expect, since it asks for calm rather than fuss. The whole knack is learning when to water and when to leave them bone dry, and even a slip or two is usually recoverable. Get that rhythm right and you'll have one of the toughest, longest-lived little plants a sunny sill can hold.
Care
The short version: give them the brightest sun you can find, pot them in a sharply draining gritty mix, and water only during their autumn and spring growth while keeping them completely dry through summer dormancy and the leaf split.
Light
Lithops want full sun or the brightest light you can offer, all year round, and a south-facing window is just about perfect indoors. If they don't get enough, the bodies stretch tall and pale rather than staying flat and compact, but that's an easy fix once you spot it.
Water
This is the part that matters most, and it's simpler than it seems. Water only during active growth in autumn and spring, soaking the gritty soil and then letting it dry all the way out before the next drink. Through summer dormancy and the leaf split, keep them bone dry, because water at the wrong moment is what leads to rot.
Soil
Give them a very gritty, sharply drained mineral or cactus mix that lets water pour straight through. Any pH from 6.0 to 7.5 will suit them nicely. The quicker the soil dries out, the safer and happier the plant.
Temperature
They're comfortable across a wide range, from about 41°F to 77°F (5°C to 25°C). A cool, dry winter rest suits them well, though it's kind to shield them from hard frost and from baking heat that might tempt them to drink when they shouldn't.
Humidity
As desert plants, they prefer low humidity and air that keeps moving, so there's no number you need to fret over here. Damp, still air is really the only thing to avoid, since it invites the rot that does them in.
Feeding
Lithops hardly ever need feeding, so you can breathe easy on this one. A dilute, low-nitrogen, high-potassium cactus fertilizer during their autumn and spring growth is more than enough, and even that is optional. Too much food only pushes soft, weak growth.
Pruning
There's genuinely nothing to trim. As the old leaf pair shrivels during renewal, just let it dry and be reabsorbed on its own, and try to resist peeling or pulling it away, since that only 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. They're quite happy in a snug container, so there's no need to hurry them along.
Size & spacing
Each plant stays wonderfully tiny, just 1 to 2 inches (2 to 5 cm) tall and about as wide, slowly gathering into a little clump over the years. A small, shallow pot will hold several with room enough to spread.
Troubleshooting
Nearly every lithops worry traces back to water and light, and the reassuring part is that most of it is easy to prevent and easy to catch. The plant wears its troubles right on its body, going soft, stretched, or wrinkled, so it helps to read those signs alongside where you are in its yearly cycle. Match what you notice below before you reach for the watering can, and you'll usually find the answer is simpler than you feared.
The body has turned soft and mushy, with a glassy, sinking look
If the body has gone squishy and see-through, you are looking at rot, and the good news is that catching it early gives you a real chance to save the plant. It nearly always follows a drink given at the wrong moment, whether through summer rest, during the leaf split, or in soil that stays soggy. Set the watering can aside, trim away every soft, rotted part with a clean blade, and settle the plant into dry, gritty mix until you see it firm 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
The body is stretching tall and pale instead of staying low
A plant that has reached upward and lost its plump, squat form is simply hungry for light, and that is an easy thing to put right. Those flat, tidy tops only stay flat when the sun is strong. Give it the brightest window you have, and let it settle into the brighter spot over a few days so the fresh light never scorches the surface.
Fix:
- Move to the brightest available position
- Introduce stronger light gradually to avoid scorch
Old leaves refusing to let go while a new pair arrives
When the old leaves hang on while the new pair pushes up beside them, it usually means the plant got water during its leaf split, and no harm has been done yet. The young growth is meant to live off the old pair as it shrinks, not off the soil. Simply hold off on all water and let those old leaves dry down and vanish on their own.
Fix:
- Withhold all water until the old leaf pair fully dries and is absorbed
Wrinkles and a shriveled look during the autumn or spring growing season
When the body wrinkles while the plant is actively growing, it is just asking for a drink, and a gentle watering will fill it back out in no time. The trick is watching the calendar. If the shriveling comes during summer rest or while the new leaves are forming, that is perfectly normal, so you can relax and let it be.
Fix:
- Resume careful watering only if the plant is in active growth
Toxicity
Here's a real weight off your mind if you keep pets or have little ones about: lithops are non-toxic through and through. Cats, dogs, rabbits, birds, and people can all share a home with them safely. Nothing harmful hides in the leaves, so a stray nibble is truly nothing to lose sleep over.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
You can rest easy with cats around. A stray nibble won't poison them, though a mouthful of the gritty mix might cause a little short-lived vomiting, and that comes from the soil rather than the plant itself.
Dogs None
A dog that chews on one will be just fine, since there are no toxic compounds to worry about. Happily, those low little bodies rarely catch a dog's interest to begin with.
Horses Safe
Horses have nothing to fear from it, and because the plant is so tiny, there's barely a mouthful to graze anyway.
Rabbits Safe
Rabbits can nibble it with no trouble at all, as the fleshy leaves hold nothing harmful.
Livestock Safe
Cattle, goats, and sheep are in no danger from it, and a windowsill succulent this small will hardly ever end up in their reach.
Birds Safe
Pet birds are welcome to peck away. There's nothing toxic inside to trouble them.
People Safe
People, children included, are perfectly safe with it. It isn't a plant you grow to eat, but a curious taste won't do any harm.
Varieties
The genus holds dozens of species, and growers fall for them because of the colors and surface patterns on their windowed tops. A handful show up again and again in collections, and any of them makes a friendly place to begin.
Lithops aucampiae
A forgiving species to start with, showing reddish-brown to coppery tops crossed by darker, branching lines.
Lithops lesliei
A popular choice you can spot by its finely netted, rusty-brown windowed tops and cheerful yellow flowers.
Lithops optica 'Rubra'
A much-loved variety whose bodies glow a striking purple-red.
Lithops karasmontana
Its pale grey to pinkish bodies wear a fine reddish pattern that runs right across the surface.
Lithops salicola
With grey-green tops and translucent windows, it forgives a little extra moisture better than most of its cousins.
How to propagate
You can raise more lithops from seed or by dividing an older clump, and while neither route is fast, both are well within reach. Each one simply asks for a little patience and a gentle 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 begin life as seed, scattered over gritty mix in spring or early autumn and kept warm and just lightly moist until the little sprouts appear. It's a lovely slow project for a patient grower, because a seedling needs 2 to 3 years to reach mature flowering size and a gentle, watchful hand with moisture the whole way through.
DivisionModerate
Divide established multi-headed clumps at repotting during active growth. · Several months to root and re-establish
If you have an older clump with several heads, you can split it during active growth, and repotting time is the natural moment to do it. Slice between the heads so each piece keeps its roots, let the cut faces dry for a while, then pot them up and give them several months to settle in and take hold.
Myths
Lithops are a type of cactus.
They are leaf succulents in the family Aizoaceae and have no close relation to the true cacti of the Cactaceae. Both simply arrived at the same water-storing idea from different corners of the plant family.
A lithops needs to be watered on a steady schedule, just like any other houseplant.
Watering them like a leafy windowsill plant is the quickest way to lose one, though it's an easy habit to unlearn. They need to stay completely dry through summer rest and the leaf split, and too much water is far and away the most common cause of death.