Split Rock succulents (Pleiospilos nelii) and Lithops, or Living Stones, are distinctive succulents known for their stone-like appearance and camouflage. These plants often cause confusion among enthusiasts due to their specialized care requirements. This article clarifies their differences and cultivation needs.
Understanding Split Rock Succulents
Pleiospilos nelii, or Split Rock, typically has two to four thick, fleshy leaves fused at the base with a central fissure. These gray-green to brown leaves often have darker dots, mimicking stony landscapes. New leaves emerge from the central split of the old leaves, which then gradually wither as new growth develops. A healthy plant usually maintains two leaf pairs; more can indicate overwatering. Split Rocks produce large, daisy-like flowers, typically yellow to coppery-orange, in late winter to early spring. These blooms open in the afternoon and close at night.
Understanding Lithops
Lithops, or Living Stones, are known for their camouflage, resembling pebbles. Each plant has two fleshy, fused leaves forming a cleft, from which new growth and flowers emerge. Their varied coloration and patterns help them blend with rocky surroundings in Southern Africa. New leaves emerge from the cleft, and the old pair shrivels and is fully absorbed, providing moisture and nutrients. Lithops produce small, daisy-like flowers, usually white or yellow, typically blooming in autumn. These flowers open during the day and close at night.
Key Distinctions and Similarities
Split Rocks and Lithops differ primarily in leaf structure and growth patterns. Split Rocks typically have two to four distinct, triangular leaves, with new leaves emerging from a central fissure. Lithops have two highly fused, rounded leaves forming a deep cleft, from which new leaves emerge, absorbing the old pair. Split Rocks often appear more angular with a rougher, dotted texture, while Lithops are smoother and more uniformly rounded, resembling pebbles. The handling of old leaves also differs: Split Rock leaves persist longer and may stack if overwatered, whereas Lithops fully absorb theirs. Flowering seasons vary, with Split Rocks blooming in late winter to early spring (yellow to coppery-orange flowers) and Lithops in autumn (white or yellow flowers).
Both are camouflaged succulents native to arid South Africa. They require bright, direct sunlight, are sensitive to overwatering, and need well-draining, gritty soil.
Care Considerations for Both
Watering is a primary care consideration, differing based on their growth cycles. For Split Rocks, water when leaves shrivel or pucker, allowing the soil to dry completely between waterings. Reduce water during summer dormancy, and provide minimal water in winter to support blooming. Overwatering can cause leaf splitting or rot; maintaining more than two leaf pairs often signals excessive moisture.
Lithops have a stricter watering schedule. Water from late spring into summer, then stop during summer dormancy. Resume watering in late summer or early autumn during active growth and flowering. Withhold water completely in winter and spring when new leaves develop and absorb old ones; watering too soon hinders this process and causes rot. If Lithops leaves appear wrinkled or sunken, it may indicate a need for water, but mushy or yellow leaves signal overwatering.
Both succulents need ample bright, direct sunlight, ideally four to five hours daily, with some protection from intense midday sun to prevent scorching. Etiolation, or stretching, can occur in low light conditions. Well-draining, gritty soil, high in inorganic material like pumice or perlite, is essential to prevent root rot. Repotting should be infrequent. Fertilization is rarely needed; if used, apply a diluted succulent fertilizer sparingly during active growth.
Common Misconceptions and Troubleshooting
The similar appearance of Split Rocks and Lithops often leads to misidentification and incorrect care. A common misconception is that all stone-mimicking succulents have identical watering needs, causing problems when Lithops are watered like Split Rocks, or vice-versa. For example, overwatering a Lithops during its leaf reabsorption phase, treating it like a Split Rock, causes rot. Conversely, underwatering a Split Rock during active growth or blooming can stunt its development.
Mushy or yellowing leaves typically indicate overwatering and root rot for both. Shriveling leaves can signal thirst for Split Rocks, but for Lithops, they often mean the plant is properly absorbing old leaves, making watering detrimental. Observing each plant’s leaf development stage is key for troubleshooting.