Lithops, often called "living stones," are fascinating succulent plants native to the arid deserts of southern Africa. To understand their watering needs, one must first understand their unique physiology and annual growth cycle. They have evolved to survive in environments with minimal and highly unpredictable rainfall by storing all necessary water in a single pair of fused leaves. Their watering schedule is not a simple calendar event but a dance synchronized with their growth stages and environmental conditions.
Our yearly routine is dictated by a predictable cycle of growth, dormancy, and renewal. Watering at the wrong time can be fatal, causing us to rot from the inside out.
Spring (The Growth Period): As daylight increases, our new leaves begin to develop inside the old leaf pair. The old leaves will slowly shrivel and transfer their moisture to the new growth. During this time, you should only water very sparingly, if at all. The old leaves are our water source; additional water is largely unnecessary and can hinder the absorption process.
Summer (The Dormant Period): This is our rest time. The intense heat of our native habitat signals us to slow down. We are most vulnerable to rot during this period. You must withhold water entirely, relying on the moisture stored within our leaves. The only exception is if we show extreme signs of wrinkling on the top and sides (not just the fissure), and even then, a tiny amount of water is all that is needed.
Autumn (The Flowering and Active Growth Period): This is our main growing season. As temperatures cool, we break dormancy, and many of us produce beautiful flowers. This is when we are most thirsty. You can begin watering, but always only after the soil is completely and utterly dry. A good deep watering followed by a full drying period is what we crave.
Winter (The Caution Period): Growth slows again as light levels drop. During this time, you should reduce watering frequency significantly. Our soil must stay mostly dry, especially if we are kept in cool conditions, as cold and wet soil is a death sentence for our roots.
Our needs are also shaped by our immediate environment. The "soak and dry" method is essential, but the timing between soaks depends on several factors.
Soil and Drainage: We demand exceptionally well-draining soil. A mix of mostly mineral grit (pumice, perlite, coarse sand) with very little organic matter is ideal. We must be planted in a pot with a drainage hole. Without this, water pools around our roots, and we will succumb to rot quickly.
Light and Temperature: We thrive in bright, direct light. More light and warmer temperatures cause the soil to dry faster, potentially shortening the time between waterings in the autumn. Less light and cooler temperatures mean the soil stays wet longer, requiring much longer periods between waterings.
Humidity: In regions of the U.S. with high humidity, the soil will take much longer to dry. You must extend the dry periods significantly between waterings to compensate for the moisture in the air.
Do not water on a schedule. Instead, learn to read our bodies. The tell-tale sign of thirst is subtle wrinkling or puckering on the top and sides of our leaves. We will feel soft to the touch. If we are firm and smooth, we are full of water and do not need more. When in doubt, it is always safer to wait. We are far more likely to die from overwatering than from underwatering. A thirsty Lithops can be revived with water; a rotted one cannot be saved.
