To understand our watering needs, you must first understand our fundamental biology. We are xerophytes, plants supremely adapted to arid environments. Our most famous feature, the spines, are modified leaves that minimize surface area to drastically reduce water loss through transpiration. Our true work, however, is done by our green, fleshy stems. These stems are engineered for water storage, consisting of a thick, spongy parenchyma tissue that can expand to hold vast amounts of water after a rare desert rain. Our outer skin is covered with a thick, waxy coating called the cuticle, which acts as a waterproof barrier. This entire physiological package is designed for one purpose: survival through long periods of absolute drought. Therefore, your watering can is not a source of daily sustenance but should mimic the infrequent, deluging storms of our native habitats.
The single most important guideline for hydrating us is the "soak and dry" method. This process directly mirrors the natural boom-and-bust water cycle we have evolved with. When it is time to water, you must do so thoroughly. Pour water evenly around the soil surface until it begins to flow freely out of the drainage holes at the bottom of the pot. This ensures that the entire root system has access to moisture and encourages deep, healthy root growth. The critical second part of this rule is to then allow the potting medium to become completely dry before you even consider watering again. You must check the soil's moisture at the root level, not just the surface; a finger inserted two inches into the soil or a wooden chopstick should come out completely dry.
There is no universal weekly schedule. The frequency between "soak" cycles is dictated by your specific indoor environment. You must observe and adjust for these factors:
Our health is deeply rooted in what we are planted in. A pot made of porous terracotta allows water to evaporate through its walls, drying the soil much faster than a plastic or glazed ceramic pot. More importantly, we require a gritty, extremely well-draining potting mix. Standard potting soil retains too much moisture and will suffocate our roots, leading to fatal rot. Our ideal medium is a specialized cactus or succulent mix, often amended with extra perlite, pumice, or coarse sand to ensure it dries out rapidly after a thorough soaking. Learn to read our body language. The signs of overwatering and underwatering can, confusingly, sometimes look similar as both lead to cell failure. Chronic overwatering will cause us to become soft, mushy, and discolored (often yellow or brown), starting at the base—a clear sign of rot. The plant may feel unstable in its pot. Underwatering, while far less immediately dangerous, will cause us to use our internal water reserves. We will appear shrunken, withered, or wrinkled and may feel limp or less rigid. The skin might look overly thin. An underwatered cactus will typically recover quickly after a deep drink, while an overwatered one often cannot be saved.
Season (Light Availability): During the spring and summer, our growth period with longer, brighter days, we are actively growing and will use water more quickly. You may water us every 10-14 days, but always verify the soil is dry first. In autumn and winter, we enter a period of dormancy due to shorter days and lower light intensity. Our growth halts, and our water requirements plummet. During this time, you may only need to water us once a month or even less frequently, just enough to prevent severe shriveling.
Temperature and Humidity: A hot, dry environment will cause potting soil to dry out faster than a cool, humid one. Air conditioning and heating systems can significantly reduce ambient humidity, accelerating evaporation.
Pot and Soil Type:
4. Recognizing the Signs of Distress
