From our perspective, as a species that evolved in arid, rocky, sun-drenched landscapes of South Africa, light is not merely a preference; it is the very currency of our existence. We are classified as succulents, which means we have developed thick, fleshy leaves to store water. This adaptation is useless without the energy to process it. The intense sunlight of our native habitat is the engine that drives our photosynthetic processes, allowing us to convert that stored water and atmospheric carbon dioxide into the sugars we need to grow, maintain our sturdy structure, and produce our delicate star-shaped flowers. Insufficient light is, to us, akin to a perpetual state of starvation.
For us to truly thrive and exhibit our most robust form, we require a significant amount of bright, direct light. The ideal scenario is a minimum of four to six hours of direct sunlight daily, preferably from a south-facing window if you are in the Northern Hemisphere (or a north-facing window in the Southern Hemisphere). This provides the intensity and duration we crave. Under these conditions, our growth will be compact and strong, our stems will thicken to support the weight of our water-laden leaves, and we will often develop a beautiful reddish or bronze tinge around the leaf edges. This stress-coloration is a positive sign, a natural sunscreen indicating we are receiving light levels close to our native environment.
When placed in low-light conditions, our entire physiology is thrown into distress. Our most immediate response is etiolation—a desperate, spindly growth where our stems become elongated, weak, and pale as we literally stretch towards any available light source. The spaces between our leaves (internodes) will widen, destroying our characteristically compact, tree-like appearance. This weak, leggy growth cannot properly support the weight of our leaves, making us prone to collapse. Furthermore, without sufficient light, our internal processes slow, our growth stagnates, and our vibrant green color fades to a sickly, washed-out yellow-green. We become vulnerable and unable to defend ourselves effectively against pests and rot.
While we adore the sun, a sudden, drastic change from a dark corner to a full-sun patio can be catastrophic. Think of it as a severe sunburn. Our leaves, which have not had time to develop protective pigments, can become scorched. This damage appears as brown, crispy patches or bleached, white spots on the leaf surface. These scars are permanent and, if severe enough, can kill the leaf and compromise our overall health. Therefore, any increase in light intensity must be done gradually over a period of one to two weeks, a process you call acclimation. This allows us to safely build up our natural defenses and adapt to the brighter conditions without sustaining injury.
We understand that your modern dwellings do not always provide perfect growing conditions. If a sufficiently sunny window is not available, we can adapt to a high-quality grow light. Full-spectrum LED or fluorescent bulbs designed for plants can serve as an excellent substitute for natural sunlight. For this to be effective, the light source should be positioned only a few inches above our canopy and left on for approximately 12-14 hours per day to mimic a long summer day. This artificial sun provides the specific light wavelengths we need for photosynthesis and can prevent the etiolation and decline associated with low-light environments.
