The Pleiospilos nelii ‘Royal Flush’, often called the “Split Rock” plant, is a unique succulent celebrated for its striking, stone-like appearance. This plant features thick, egg-shaped leaves with a distinct purplish-red coloration, often speckled with tiny dark dots, allowing it to camouflage with granite pebbles in its natural habitat. Originating from the Great Karoo region of South Africa, it is a slow-growing plant that can reach up to 3.2 inches tall and 4 inches in diameter.
Care Requirements
Light
The ‘Royal Flush’ thrives in bright, direct sunlight, needing at least six hours of light daily to maintain its vibrant purplish-red pigmentation. Placing it near a south-facing window indoors or in a location with full sun exposure outdoors is ideal. Acclimate the plant gradually to intense direct sunlight to prevent sunburn, especially if it was previously in lower light conditions. Sufficient light intensifies its coloration; insufficient light can cause it to revert to a greener shade or become etiolated.
Watering
Watering the ‘Royal Flush’ requires a careful “less is more” approach, as overwatering is a common cause of issues. Allow the soil to dry out completely between waterings, and then water deeply but infrequently. The plant signals its thirst when the oldest leaves show a slight wrinkling or softness. Avoid watering when the plant is actively splitting or when it has more than two pairs of leaves, as this can lead to rot. During its growing season in spring and fall, watering every two to four weeks may be appropriate, but in summer and winter dormancy, watering should be significantly reduced or withheld entirely.
Soil
An extremely well-draining, gritty soil mix is essential for the ‘Royal Flush’ to prevent root rot. The ideal composition should be low in organic matter, mimicking its natural rocky and sandy South African habitat. A common recommendation is a mix containing 75-80% mineral grit like pumice, perlite, or coarse sand, combined with a small amount (20-25%) of succulent potting mix. This porous blend ensures rapid drainage and aeration for root health.
Temperature and Humidity
The ‘Royal Flush’ prefers warm temperatures, ideally between 60°F and 80°F (15°C to 27°C), during its active growing season. While it can tolerate cooler temperatures, it should be protected from freezing, as it does not tolerate temperatures below 50°F (10°C) and has a frost tolerance down to about 25°F (-3.9°C). Its desert origins mean it has very low humidity requirements and thrives in arid conditions. Good air circulation is also beneficial for its overall health.
Unique Growth Cycle and Flowering
The ‘Royal Flush’ exhibits a growth cycle centered around its “splitting” phenomenon. New leaves emerge from the deep fissure between the older, existing leaf pair. As the new leaves grow, the plant reabsorbs moisture and nutrients from the older, outer leaves, which then shrivel and dry. This process is essential for the plant’s health. Do not water during this splitting phase, as excess moisture disrupts reabsorption and can lead to unhealthy stacking or rot. Ideally, the plant should maintain only one to two pairs of leaves at a time.
The ‘Royal Flush’ produces large, daisy-like flowers that are typically deep rose or pink with a white center. These blooms can reach up to 3 inches in diameter. Flowering occurs in early spring and can extend into autumn or winter. The flowers have a unique habit of opening in the mid-afternoon and closing again just after sunset. The blooms have a coconut-like fragrance.
Troubleshooting Common Problems
Overwatering is the most frequent issue encountered with ‘Royal Flush’, often leading to rotting or mushy leaves. If leaves become yellow, swollen, or translucent, it indicates too much water. Withhold water and check roots for rot.
Wrinkling or shriveling of the outer leaves is a normal part of the splitting process, as the plant reabsorbs water from them. However, if inner leaves show significant wrinkling or the entire plant appears shriveled, it indicates extreme underwatering. In such cases, a thorough but careful watering can help rehydrate the plant.
Lack of proper splitting or development of more than two leaf pairs (stacking) signals overwatering. The plant produces new leaves without fully reabsorbing the old ones because it has too much external water, preventing it from drawing on its internal reserves. Reducing watering frequency will encourage the plant to correctly absorb the older leaves.
If the ‘Royal Flush’ loses its vibrant purple coloration and appears greener or becomes elongated (etiolated), it is a sign of insufficient light. Moving the plant to a brighter location with more direct sunlight will help restore its characteristic pigmentation and compact form.
While pest-resistant, ‘Royal Flush’ can be affected by common succulent pests like mealybugs or red spiders. Regularly inspecting the plant allows for early detection and treatment, such as wiping pests away with a cotton swab dipped in rubbing alcohol.