To understand our watering needs, you must first understand what we are. We are Lithops, often called "living stones," native to the extremely arid deserts of southern Africa. Our entire evolutionary purpose is to survive in an environment where rainfall is scarce, unpredictable, and often followed by intense, water-evaporating heat. Our physical form is a direct adaptation to this. Our above-ground body consists of two fused, succulent leaves that act as a water reservoir. This pair of leaves contains all the moisture we need to survive for months. Our roots are fine and relatively shallow, designed to absorb a sudden downpour quickly before it vanishes into the deep, dry soil. Therefore, our core biological imperative is not to seek constant moisture but to avoid it. Overwatering is a far greater and more immediate threat to our survival than underwatering.
You cannot water us on a fixed weekly or monthly schedule. Our needs are dictated entirely by our internal growth cycle, which is synchronized with the seasons. Your watering must follow this cycle precisely.
Phase 1: Spring Growth (Approx. March-May): This is our period of active growth following winter dormancy. As the days lengthen and temperatures warm, you can begin watering. Water deeply (soak the soil completely) only when the soil is completely dry and our leaves show slight signs of wrinkling or softness on the sides. This may be every 2-4 weeks, depending on your local climate and pot conditions.
Phase 2: Summer Dormancy (Approx. June-August): We enter a rest period to escape the intense heat. During this time, you must drastically reduce or completely stop watering. High heat combined with moisture around our roots will lead to fatal rot. Only consider a very light watering if we show extreme signs of shriveling and only if we are in a climate with very low humidity.
Phase 3: Autumn Flowering and New Leaf Pair Development (Approx. September-November): This is our second and most crucial watering period. As temperatures cool, we prepare to flower and, internally, a new leaf pair begins to form. Resume deep watering only when the soil is completely dry. This supports flowering and the growth of the new leaves inside the old ones.
Phase 4: Winter Dormancy (Approx. December-February): We are completely dormant. Withhold all water. The old leaf pair will slowly shrivel and transfer its stored moisture and nutrients to the new pair growing inside. Watering now can cause the old leaves to rehydrate and refuse to transfer resources, ultimately rotting both the old and new growth.
The vast climatic diversity across the USA means our needs will vary. A Lithops in humid Florida will need far less frequent watering than one in arid Arizona. The key environmental factors are temperature, humidity, and light intensity. Furthermore, the pot itself is critical. We demand an extremely well-draining soil mix, typically 80-90% mineral grit (pumice, perlite, coarse sand) and only 10-20% organic matter. We must be planted in a pot with a drainage hole. A deep pot that allows our taproot to stretch is ideal. A clay terracotta pot is beneficial as it wicks away excess moisture from the soil. The better the drainage and the more airflow, the safer an occasional extra watering will be.
Forget the calendar. The most reliable method is to observe us. The sides of our leaf pairs will develop slight wrinkles and feel slightly soft or spongy to a gentle touch when we have used our internal water reserves and are ready for a drink. This is your signal. If we are firm, smooth, and bulging, we are full of water and must not be watered. The top of the leaves should also be observed; if it is sunken in, it is a sign of thirst. However, a split in the top is a natural part of our growth cycle as the new leaves emerge, not a sign of thirst. When in doubt, it is always safer to err on the side of dryness. Our tolerance for drought is measured in months, while our tolerance for overwatering is measured in days.
