Lithops, often called “living stones,” are succulent plants that mimic pebbles in their natural South African habitats. A common concern arises when these typically firm plants become squishy. Understanding why a Lithops might feel soft is crucial for its continued health. This article explores the reasons behind a squishy Lithops and provides guidance on how to address this issue.
Understanding Lithops Physiology
Lithops have developed adaptations to thrive in arid environments. Their most prominent feature is a pair of fleshy, fused leaves largely buried underground, with only a translucent “window” at the top exposed to sunlight. These leaves serve as water storage organs, allowing the plant to survive prolonged periods without rainfall. A deep taproot further aids in anchoring the plant and seeking moisture deep within the soil.
This structure allows Lithops to store significant water, influencing their environmental reaction. They also undergo a distinct growth cycle where new leaves emerge from between the old ones, absorbing moisture and nutrients from the older pair. This natural process involves the gradual shriveling of old leaves, which can sometimes be mistaken for a problem.
Causes of Squishy Lithops
Overwatering and Rot
Overwatering is the primary cause of a squishy Lithops. Excess moisture can cause the plant’s cells to burst, resulting in a soft, mushy texture. This mushiness can quickly progress to fungal or bacterial rot, a destructive condition.
Signs include overly swollen or mushy leaves, often with brown or black discoloration. A foul odor indicates advanced rot. In severe cases, the plant may disintegrate, and the root system turns dark, soft, or slimy.
Natural Growth Cycle
Squishiness can also be a normal part of the Lithops’ natural growth cycle. Lithops typically produce a new pair of leaves once a year, usually during fall or winter. During this period, the older outer leaves transfer their stored water and nutrients to the new, emerging leaves.
As the new leaves develop, the old ones will gradually shrivel, become soft, and dry out into papery husks. This process results in wrinkly or deflated old leaves, not a mushy texture. New, firm leaves should be visible emerging from the split in the center, confirming a healthy transition.
Action Steps for a Squishy Lithops
Once the cause of squishiness is identified, immediate action is necessary. If overwatering and rot are suspected, halt all watering immediately. Carefully remove the Lithops from its pot to inspect the roots and surrounding soil. Any dark, mushy, or foul-smelling roots should be pruned away using a sterile, sharp tool.
After trimming, allow the plant to air dry for several hours or even a few days in a well-ventilated area away from direct sunlight. This drying period prevents further rot before repotting into fresh, dry, gritty soil. If rot is extensive, the plant may be beyond saving, and discarding it prevents pathogen spread. If squishiness is due to the natural growth cycle, no intervention is needed. Continue to withhold water until the old leaves have completely dried into papery husks and the new leaves are fully formed. Watering during this period can disrupt the process, as new leaves absorb moisture from old ones.
Preventative Care for Healthy Lithops
Healthy Lithops growth relies on mimicking their native arid conditions. Watering is the most important aspect, requiring infrequency. Only water when the plant shows clear signs of thirst, such as significant wrinkling or concaving of the tops, not just minor softness. During their dormant periods, typically summer and winter, watering should be significantly reduced or stopped entirely.
Lithops require well-draining, gritty soil to prevent water retention and root rot. An ideal mix consists of a high percentage of inorganic materials like pumice, perlite, or coarse sand, with little organic matter. Provide bright, direct sunlight for at least 4-5 hours daily, as insufficient light can lead to stretching and weakness. Good air circulation also helps evaporate lingering moisture and maintain a healthy environment.