Succulents are cherished for their unique forms and drought tolerance, but a common concern is when they begin to turn white. This change can range from a natural protective feature to a sign of distress, requiring careful observation to determine the cause. Understanding why your succulent is turning white is the first step toward effective care.
Understanding Farina: The Natural White Coating
Many succulents naturally produce farina, a powdery, waxy substance appearing as a white or bluish-silver film on their leaves and stems. This natural coating is a crucial protective layer. Farina acts as a natural sunscreen, reflecting ultraviolet rays and preventing sunburn. It also serves as a hydrophobic barrier, repelling water to prevent excessive moisture absorption and reduce rot. This waxy layer helps keep leaves clean by causing water to bead up and roll away, carrying dirt with it. Farina is delicate and easily rubbed off, so handle succulents with care to preserve its protective qualities.
Common Reasons Your Succulent is Turning White
Sunburn and Bleaching
Excessive exposure to direct, intense sunlight can cause a succulent’s leaves to turn pale, white, or bleached. This discoloration typically appears on parts most directly exposed to the sun, resulting from chlorophyll degradation and loss of green pigmentation. Affected areas may become thin or crispy. To address this, gradually acclimate your succulent to brighter light over several weeks. Moving the plant to a location with filtered or less intense sunlight, especially during the hottest parts of the day, can prevent further damage.
Pest Infestations
White discoloration can signal a pest infestation, particularly from mealybugs. These soft-bodied insects appear as small, white, cottony masses, typically found in leaf axils, on undersides of leaves, or along stems. Mealybugs feed by sucking sap, leading to weakened growth, distorted leaves, and a white, powdery appearance from their waxy residue and sticky honeydew. To treat, dab individual mealybugs with a cotton swab dipped in 70% isopropyl rubbing alcohol, or apply an insecticidal soap. Repeated applications may be necessary to eradicate the infestation.
Fungal Infections
Powdery mildew is a common fungal infection appearing as white, powdery spots or patches on succulent leaves and stems. This fungal growth spreads rapidly, covering significant portions of the plant, favored by high humidity, poor air circulation, and cooler temperatures. The fungus thrives in stagnant, moist environments, hindering photosynthesis and potentially leading to stunted growth or leaf distortion. Improving air circulation, reducing humidity, and promptly removing severely infected leaves can help manage the spread. For persistent cases, apply a fungicide labeled for powdery mildew on succulents.
Mineral Deposits from Water
Hard water or tap water with high mineral content can leave white, chalky, or crusty deposits on succulent leaves, especially with overhead watering. These mineral residues, primarily calcium and magnesium carbonates, remain after water evaporates. While often cosmetic, a thick layer of deposits can impede light absorption and photosynthesis. To mitigate this, use distilled, rainwater, or filtered water for irrigation. Wiping leaves gently with a soft, damp cloth can remove existing deposits. Adjusting to bottom-watering can also prevent water from accumulating on the leaves.
Preventing Future White Discoloration
Preventing white discoloration involves consistent care tailored to succulent needs. Provide appropriate lighting by gradually introducing succulents to brighter conditions to avoid sunburn, ensuring ample but not excessive light. Implement proper watering techniques, such as allowing soil to dry completely between waterings and avoiding overhead watering, to prevent fungal issues and mineral buildup. Adequate air circulation helps deter fungal growth by reducing humidity. Regularly inspect succulents for early signs of pests, particularly mealybugs, for prompt intervention. These proactive measures contribute to your succulents’ overall health and vibrant appearance.