Lithops, often called living stones, are unique succulent plants that have evolved to resemble pebbles in their native arid environments. This mimicry involves a highly specialized structure, consisting of two fleshy leaves that serve as massive water reservoirs. When a Lithops suddenly feels soft or squishy, it is an alarming signal that the plant is in serious distress, indicating a profound failure in its specific care requirements.
The Primary Cause of Squishiness: Rot
For a Lithops, a soft or squishy texture is almost always a result of internal rot, which is caused by an excess of moisture. These plants are adapted to regions with sporadic rainfall, meaning their physiology is designed to absorb and store water efficiently. The plant’s body is comprised of water-storing cells, and when subjected to constant moisture, these cells become engorged and eventually rupture, leading to cell death and decay. The rot typically begins in the root system and then progresses upward into the fleshy leaves. This decay process is often fueled by fungal or bacterial pathogens that thrive in consistently wet, anaerobic conditions. The use of incorrect potting medium is a major contributing factor, as standard organic potting soil retains moisture for far too long, smothering the roots and creating a perfect environment for rot organisms to multiply. This is why a squishy Lithops is usually a plant actively decomposing from the inside out.
Determining the Severity of Damage
Before attempting any treatment, you must accurately assess the extent of the internal damage, which determines the plant’s chance of survival. Immediately unpot the Lithops and gently remove all soil particles from the taproot and the plant’s base. The feel of the tissue is the most important diagnostic tool. Healthy Lithops tissue, even if slightly dehydrated, will feel firm and solid. Rotting tissue, in contrast, will be dark brown or black, slimy, and easily collapse when pressed. A foul, musty odor emanating from the base or roots is a definitive sign of severe, active bacterial or fungal rot. If the entire plant body has turned to a complete, shapeless mush, it is likely too far gone to save. However, if the squishiness is confined to the outer leaves or the very tip of the taproot, and the central portion remains firm and pale, immediate intervention may still be successful.
Emergency Steps to Save a Squishy Lithops
The initial emergency protocol involves cutting away all infected tissue to prevent the rot from spreading further into the healthy parts of the plant. First, sterilize a sharp blade, such as a hobby knife or scalpel, using rubbing alcohol. Carefully begin slicing away the rotted tissue, starting from the roots or the bottom of the plant’s body. You must continue making thin slices until you reach tissue that is completely firm, dry, and pale white or green. The goal is to remove every trace of brown, dark, or translucent decay, even if this means cutting the plant down to a small, headless stump.
After the cutting is complete, the exposed wound must be treated to prevent re-infection. Dust the entire cut surface with elemental sulfur powder or ground cinnamon, both of which possess antifungal and antibacterial properties that act as a sealant. The plant must then be left unpotted in a shaded, dry, and well-ventilated location for a period of three to seven days. This crucial drying time allows the wound to fully desiccate and form a hard, protective callus. Repotting the Lithops before the cut surface has fully callused will expose it to pathogens in the soil. Once a hard, dry scab has formed over the wound, you can repot the plant into a bone-dry, highly inorganic soil mix. Do not water the newly repotted plant for at least two weeks to allow it time to establish new, fine feeder roots.
Essential Care to Prevent Future Problems
Long-term survival depends on replicating the arid, mineral-rich environment of the Lithops’ natural habitat.
Soil Composition
The correct soil mix is predominantly inorganic, containing 80% to 90% mineral components like pumice, lava rock, coarse sand, or grit. This composition ensures that water drains almost instantly, preventing the prolonged moisture retention that leads to rot. The remaining 10% to 20% can be a low-organic succulent mix to provide minimal nutrients.
Watering Cycle
Watering must strictly align with the Lithops’ distinct annual growth cycle, which involves periods of active growth and dormancy. New leaves are typically grown by absorbing the moisture from the older, outer leaf pair, a process known as splitting. During this time, which often occurs in winter and spring, you must not water the plant at all, as the old leaves need to dry out completely. Watering during the splitting phase can interrupt the absorption process and cause the plant to rot. Only provide water when the plant is not splitting and the sides of the leaves begin to show distinct, horizontal wrinkles, which is the visual cue for thirst.
Light Requirements
Lithops also require ample light, ideally four to five hours of direct sun daily, supplemented with bright indirect light. Insufficient light can exacerbate moisture problems by slowing down the plant’s metabolic rate and reducing water evaporation.