Living stone

Karas mountains living stone

Closely related sister species — distinguished by greyish-cream rather than reddish-brown dorsal colour. Care identical.

Cone plants

Smaller pebble-mimic relatives in the same family. Conophytum has a single rounded body without the obvious transverse fissure of Lithops, and flowers from a small apical opening rather than a central split.

Split rock / Living granite

Same family (Aizoaceae) but much larger — bodies are 5–10 cm across, granite-grey with darker speckles, and obviously split at the top. Often sold alongside Lithops as 'living rocks' but is not a Lithops.

Direct sun, at least 4 hours of unfiltered daylight.

Lithops needs the most direct sun of any popular houseplant — a south-facing window with no curtain is the minimum. In Nordic latitudes the summer is fine; the winter is the killer. October–February light alone is too dim, and bodies stretch (etiolate) into elongated cones losing their pebble shape. Either accept the etiolation as cosmetic damage that will correct over the next leaf-renewal cycle, or supplement with a strong full-spectrum grow light (above 50 W per square metre) for 12–14 hours daily.

Seasonal: Nordic latitudes above ~55°N: bodies WILL etiolate without grow lights from November–February. The new spring leaves emerge correctly-shaped if the plant returns to bright sun by April.

Twice in autumn, twice in spring. Bone-dry summer (May–August) and winter (November–February).

The Lithops watering rhythm reverses everything you know about plants. Active growth is in autumn and spring; summer and winter are dormancy when the plant draws on stored water and any irrigation rots the roots. Water once thoroughly in early autumn (September) when bodies start to show new growth from the fissure, again in mid-October. Stop watering by November. Keep bone-dry through winter while the new leaves develop inside the old ones. Resume in March–April with one thorough watering, then a second 3 weeks later. Stop watering by May. Through summer (May–August) the plant looks shrivelled and partially withdrawn into the soil — this is normal dormancy. Resist watering. Lithops rotted in summer is the single most common kill mechanism.

Seasonal: If old leaves haven't fully shriveled by mid-April, do not water — the plant is still drawing moisture from them. Premature watering during leaf renewal causes the old leaves to refill instead of absorbing into the new pair, leading to a stacked deformity.

Almost pure mineral grit — 70 % inorganic, 30 % organic at most.

Mix is unlike any standard houseplant blend: 50 % coarse pumice or perlite, 20 % crushed lava rock or grit, 20 % cactus mix, 10 % peat-free houseplant mix. Top-dress with a 1 cm layer of mineral grit so the body sits on stone, not damp organic matter. The taproot needs to descend deeply, so prefer pots at least 8–10 cm deep with strong drainage. A standard 'cactus and succulent' mix from a nursery is usually too organic — amend with extra pumice 1:1.

20–40 % is ideal; tolerates 15 %.

Lithops actively dislikes humid air. The species evolved in semi-desert habitat where afternoon humidity drops below 25 %. Damp stagnant air in a bathroom or kitchen invites fungal infections at the body-soil interface. Open windows, fans, and dry rooms are all helpful. Never mist Lithops — water on the body during dormancy is a sure rot vector.

10–28 °C; tolerates brief 5 °C dry.

Lithops handles a wide temperature range as long as soil stays dry. Cool dry winter conditions (10–15 °C, no water) actually trigger better leaf renewal in spring. Sustained heat above 30 °C without ventilation can scorch the dorsal surface, especially under glass on a south window. A brief frost down to 5 °C is survivable if the plant is bone-dry; wet soil plus freezing temperatures kills.

Optional — half-strength low-nitrogen feed once in spring and once in autumn.

Lithops is adapted to nutrient-poor mineral soils and grows fine without fertiliser. If feeding, use a low-nitrogen cactus formula (e.g. 2-7-7 NPK) at half-strength, once in early spring and once in early autumn. High-nitrogen feed produces soft bodies that split open, rot, or fail to renew leaves correctly.

Do not remove old shrivelled leaves — let the plant absorb them.

The most counterintuitive Lithops care rule: when old leaves shrivel to a paper husk in spring, leave them alone. The new emerging body is still drawing residual moisture from the old leaves; pulling them off prematurely starves the new growth and the plant can fail. Only remove the husk after it has dried completely and detaches with a gentle pull — usually June or July. The same applies to a flower — let the seed capsule dry on the plant before removing.

Every 3–5 years in early autumn before active growth.

Lithops resents disturbance. Repot only when the cluster has clearly outgrown its pot or when soil has degraded into compacted organic matter. Best timing is late August to early September, after summer dormancy and before autumn watering resumes. Use a deep narrow pot to accommodate the long taproot. Plant bodies should sit with their tops just above the soil line — burying them too deep induces rot. Withhold water for 2 weeks after repotting to let any damaged roots heal.

No documented toxicity in humans. The genus is not used as food but is regarded as harmless.

Lithops is not formally listed in the ASPCA toxic or non-toxic plants database. Veterinary toxicology literature reports no documented poisoning cases for the genus, and the bitter taste of the leaves makes ingestion unusual. Generally regarded as safe for cat households, but absence of a formal ASPCA listing means caution is warranted if a cat is observed chewing.

Lithops is not formally listed in the ASPCA toxic or non-toxic plants database. No documented poisoning cases. Generally regarded as safe for dog households, but absence of a formal ASPCA listing means caution is warranted.