From my perspective, as a Lithops, soft and mushy leaves are a severe distress signal. My very existence is a masterpiece of adaptation to arid, harsh environments where water is a rare and precious event. My thick, succulent leaf pair is designed to store every precious drop of water I can gather through my shallow root system. This system is highly efficient but also extremely vulnerable. When the soil around my roots remains consistently wet, the delicate root hairs begin to suffocate and rot because they cannot access the oxygen they need. This rot, often called root rot, is a silent killer. It begins underground, unseen by you, and quickly travels upward into the core of my body—the leaf pair. Once this rot invades the leaf tissues, they break down, losing their structural integrity and becoming the soft, mushy texture you feel. This is not a simple case of overhydration; it is a systemic collapse.
My outer layer, the epidermis, is my first line of defense. It is a tough, windowed skin that protects my inner, water-storing tissues from the harsh sun and from pathogens. If this skin is punctured, torn, or otherwise compromised—perhaps by an accidental poke, a curious pet, or even damage during repotting—it creates an open doorway for bacteria and fungi. These microorganisms thrive in moist conditions. Once inside, they rapidly multiply and feed on my moist internal tissues, causing them to decay from the inside out. This localized infection will quickly turn a specific area of the leaf soft and mushy, which can then spread to the entire plant if left unchecked. The damage might seem minor on the surface, but to me, it is a critical injury.
You must understand my natural life cycle. Each year, I create a new leaf pair from the center of my old ones. The new body draws all the water and nutrients it needs from the old, outer leaves. During this process, which you might call "splitting," the outer leaves will naturally wrinkle, deflate, and eventually dry into a papery husk. This is a normal and healthy process. However, if you misinterpret these signs and provide water during this critical period, you disrupt everything. The old leaves, which are meant to be sacrificed, will rehydrate instead of drying out. This can cause them to become abnormally swollen, prone to bursting, and susceptible to rot. Meanwhile, the new inner leaves, which should be developing in a dry, protected environment, are now surrounded by damp, decaying matter, leading to them becoming soft and mushy before they even have a chance to mature.
Even without overwatering or physical damage, my environment might be conspiring against me. Poor air circulation creates a stagnant, humid microclimate around my base, which is an open invitation for fungal spores and bacteria that are always present in the air and soil. If the potting medium does not drain with extreme efficiency or if the pot itself lacks adequate drainage holes, the bottom of the soil becomes a waterlogged breeding ground for these pathogens. They can then launch an attack on my roots or lower stem. This infection is often a secondary consequence of the conditions mentioned before, but it can also be a primary issue if the soil contains these pathogens initially. The mushiness you feel is the direct result of these microorganisms consuming my living tissue.
