Living Stones, Lithops, are unique succulent plants known for their remarkable camouflage. They mimic pebbles and stones, an adaptation that helps them evade herbivores in their native arid habitats of Southern Africa. These fascinating plants consist of two thick, fleshy leaves fused together, often with a fissure from which flowers emerge. Their stone-like appearance, with various patterns and colors, makes them a captivating addition to any plant collection.
Light and Environmental Needs
Lithops require significant light, ideally four to five hours of direct morning sun, followed by partial afternoon shade. A south-facing window or unobstructed eastern exposure works well indoors. Insufficient light causes etiolation, where plants stretch, lose their compact shape, and can rot. While they appreciate strong light, intense midday sun in hotter climates can lead to sunburn or scorching.
Lithops are adapted to warm temperatures, tolerating up to 100 degrees Fahrenheit, but flourish between 65 to 80 degrees Fahrenheit. They need fresh air and tolerate dry indoor air; high humidity is detrimental. Temperatures below 40 degrees Fahrenheit are not tolerated, requiring protection from freezing.
Watering Your Living Stone
Correctly watering Lithops is crucial; overwatering is the primary cause of plant failure. These succulents store water in their leaves and survive extended droughts. A “less is more” approach is paramount: it is safer to underwater than to overwater.
Signs a Lithops needs water include slight shriveling or a concave appearance on its top surface. When watering, use the “soak and dry” method: thoroughly drench the soil until water drains, then allow the potting medium to dry completely before watering again. Water in the mornings so excess moisture evaporates quickly.
Avoid watering during dormancy (summer and winter). Do not water when new leaves are forming and absorbing the old ones, as this disrupts natural development. After flowering, cease watering until new leaves are well-developed. If a plant appears shriveled during dormancy, a very light, shallow watering (moistening only the top half-inch of soil) may restore firmness, but avoid deep watering.
Soil and Nutrition
Lithops require an extremely well-draining, gritty soil mix, mimicking their natural rocky and sandy habitats. This substrate prevents water from lingering around roots, essential to avoid rot. Suitable components include pumice, perlite, coarse sand, and decomposed granite, with minimal organic matter. Mixes with at least 50% drainage material are recommended.
Commercially available cactus or succulent mixes often contain too much organic material and benefit from additional inorganic amendments. Lithops have extensive root systems, so choose a pot three to five inches deep for ample root growth. These plants have minimal nutritional needs and do not require regular fertilization. If you fertilize, apply a very diluted, low-nitrogen, high-potassium succulent fertilizer sparingly, perhaps once during their active growing season.
Understanding the Growth Cycle
Understanding the annual growth cycle of Lithops is fundamental for successful cultivation, as it directly dictates watering patterns. Lithops begin active growth in the fall, continuing through winter and into spring. During this period, new leaves develop inside the existing ones. The old leaves shrivel and are absorbed by the new growth, providing essential moisture and nutrients.
Flowering occurs in autumn and early winter, with daisy-like yellow, white, or pale orange flowers emerging from the fissure. These flowers open in the afternoon on sunny days and close at night. After flowering, plants enter a dormant phase (summer and winter dormancy, depending on species and climate). During dormancy, Lithops conserve water by relying on stored moisture, making it a time to withhold watering to prevent rot. The cycle then repeats with new leaves emerging as temperatures cool, initiating another growth period.
Repotting and Propagation
Repotting Lithops is necessary every few years, especially when their extensive root system outgrows the container or the soil mix degrades. The best time to repot is in spring, after new leaves have fully emerged and old ones have completely withered. Use a similar gritty, well-draining mix, ensuring the plant’s taproot has sufficient depth. Do not bury the plant too deep; the Lithops should sit slightly above the soil surface. Avoid immediate watering after repotting unless the plant appears distressed.
Lithops can be propagated through division or from seed. Division is possible when a mature plant forms multiple heads; carefully lift the plant, gently separate roots, ensuring each new section has a portion of the taproot. Replant these divisions immediately into appropriate soil. Growing Lithops from seed is a slower process, taking months for germination and years for plants to reach maturity and flower. This method involves sprinkling seeds over a moist, gritty medium and maintaining humidity until germination, gradually reducing moisture as seedlings establish.
Troubleshooting Common Issues
One of the most frequent problems with Lithops is rot, primarily caused by overwatering. Symptoms include mushy or yellowing leaves and a general decline. To address rot, cease all watering immediately and ensure the plant is in a well-draining medium. Often, once rot sets in, it can be irreversible, but prompt action may save the plant.
Insufficient light leads to etiolation, where Lithops stretches, becoming tall and elongated rather than remaining compact. This condition is addressed by gradually increasing light exposure. Introduce brighter light slowly to prevent sunburn, as stretched plants are more susceptible to scorching.
Shriveling or wrinkling can indicate either underwatering or the natural process of old leaves being absorbed by new growth. If wrinkles appear primarily on the sides and the plant feels soft, it likely needs water. However, if old leaves are shriveling and becoming papery while new growth is visible in the central fissure, this is a normal part of the growth cycle, and watering should be withheld. Differentiating between these two scenarios is key to appropriate care.