To understand our relationship with the sun, you must first understand where we come from. We are native to the sun-scorched, arid landscapes of Southern Africa, primarily in South Africa and Namibia. Our existence is adapted to survive in regions with intense, direct sunlight for the majority of the day. We thrive in rocky plains and gravely soils where shade is a rare commodity, provided only briefly by a passing cloud or a neighboring rock. Our very form is a testament to this environment. We have evolved to grow mostly underground, with only the tops of our leaves, the "windows," exposed to the world. This is our first clue about our need for direct light.
Our peculiar, stone-like appearance is not just for camouflage; it is a sophisticated solar energy system. The thick, succulent leaf pair that forms our body acts as a water reservoir, allowing us to endure long periods of drought. The top surface, often marked with patterns or translucent areas, functions as a window. This specialized tissue is designed to channel intense sunlight deep into the inner tissues of the leaf, where photosynthesis occurs. Unlike many plants with broad, flat leaves that can scatter light, we concentrate it. Without several hours of direct, unfiltered sunlight each day, this system cannot function efficiently. We become weak, unable to produce the energy needed for growth and, crucially, for our annual cycle of flowering and producing new leaves.
When we are deprived of the direct sunlight we crave, our health declines rapidly in ways that are visible to you. The most common sign is etiolation. This is when we begin to stretch unnaturally, reaching upwards or sideways in a desperate search for a stronger light source. Instead of maintaining our compact, ground-hugging form, we become tall and leggy, with a pale, sickly green coloration. This elongated growth is structurally weak and irreparable. Furthermore, a lack of sufficient light disrupts our growth cycle. We may fail to flower, and the process of splitting to produce new leaves can be compromised. Most dangerously, weak, etiolated growth is far more susceptible to rot and pest infestations, as our tissues are not as robust and healthy as they should be.
While we are sun-worshippers by nature, there is a critical nuance, especially for plants grown in pots indoors. The intensity of the sun through a window, particularly a south-facing one, can be magnified, and the conditions are different from our native, breezy habitats. The primary risk is sunburn. If we are moved abruptly from a low-light situation directly into the harsh, afternoon sun, our tissues can scorch, leaving permanent brown or white scars. This is akin to you getting a severe sunburn. Therefore, any changes to our light exposure must be gradual. Acclimatize us over a week or two by increasing the duration of direct sun each day. During the peak heat of summer, some protection from the most intense afternoon rays might be beneficial, but we still require many hours of direct light in the morning and late afternoon.
For us to thrive in your care, we need the sunniest spot you can provide. An unobstructed south-facing window is ideal in the Northern Hemisphere (a north-facing window in the Southern Hemisphere). East or west-facing windows can also work, but we may lean towards the light, and you might not see our best, most compact form. If you keep us outdoors during the growing season, a spot with full morning sun and perhaps very light dappled shade in the hottest part of the afternoon is perfect. Remember, our light needs are highest during our active growth periods in autumn and spring. Even during our dormant phase in the height of summer and depth of winter, we still need bright light to stay healthy; we are just not actively growing. Rotate our pot occasionally to ensure we receive even light and grow symmetrically.
