The String of Pearls (Senecio rowleyanus or Curio rowleyanus) is a popular succulent with distinctive, spherical leaves. White discoloration of these “pearls” often indicates underlying stress or damage, and understanding its appearance can help diagnose the issue.
Understanding “White Pearls”
The appearance of white pearls varies, providing clues to the plant’s distress. Bleached white and crispy pearls suggest excessive light exposure and scorching. Mushy, pale white pearls usually indicate overwatering and potential root decay. Shriveled and pale pearls are typically a sign of dehydration or insufficient water. In some cases, a powdery white substance covering the pearls indicates a pest infestation.
Primary Causes and Solutions
Overwatering and Root Rot
Overwatering is a common cause for String of Pearls turning white and mushy. Excessively moist soil deprives roots of oxygen, leading to root rot. This decay prevents nutrient absorption, causing pearls to become translucent, soft, and eventually pale or white. To address this, check soil moisture; if wet, allow it to dry completely before the next watering. If root rot is suspected, remove the plant, inspect roots for black, brown, or slimy sections, and trim diseased portions before repotting in fresh, well-draining succulent soil.
Underwatering and Dehydration
Insufficient watering leads to white or pale pearls, typically appearing shriveled, dry, and flattened. This occurs as the plant depletes water reserves stored within its bead-like leaves, causing them to wrinkle and lose plumpness. To resolve this, water thoroughly when the soil is completely dry. Consistent, deep watering is important for hydration. After watering, ensure any excess water drains from the pot.
Excessive Sunlight
Too much direct and intense sunlight can cause the pearls to become bleached, scorched, and turn a crispy white or pale yellow. String of Pearls thrives in bright, indirect light, often preferring morning sun over harsh afternoon sun. If the plant is receiving too much direct light, especially during peak hours, relocate it to a spot with filtered sunlight. An east-facing window is often ideal, providing gentle morning sun without the intensity of midday or afternoon rays.
Pest Infestations
Certain pests, particularly mealybugs, can cause a white appearance on String of Pearls. These small, oval-shaped insects secrete a white, cottony substance as they feed on the plant’s sap, making the pearls appear covered in white fuzz. If mealybugs are identified, they can be removed by dabbing them directly with a cotton swab dipped in 70% isopropyl alcohol. For more widespread infestations, spraying the plant with insecticidal soap or a diluted neem oil solution can help control the pests.
Less Common Factors and Overall Health
Nutrient Deficiencies
A lack of essential nutrients can contribute to plant stress and discoloration, though rarely a pure white hue. Yellowing leaves may signal nutrient deficiencies. During the active growing season in spring and summer, apply a balanced, diluted liquid succulent fertilizer every two to four weeks. Avoid over-fertilizing, as this can damage roots.
Temperature Extremes
Sudden or prolonged exposure to temperature extremes can stress the plant, causing the pearls to appear unhealthy or pale. String of Pearls prefers stable indoor temperatures, typically ranging from 21°C to 27°C (70°F to 80°F). Protecting the plant from cold drafts, air conditioning vents, or direct heat sources helps maintain a consistent environment. Cooler temperatures, around 13°C to 18°C (55°F to 65°F), during winter can be beneficial for a rest period.
Natural Aging
As pearls age, especially on longer, older strands, they might naturally lose some vibrancy and shrivel slightly. While this does not typically result in a stark white appearance, older pearls may become less plump and green over time.
Preventative Care for Thriving String of Pearls
Preventing white pearls involves consistent care. Ensure bright, indirect light and use well-draining soil with proper drainage. Water only when the soil is completely dry, and regularly inspect for pests.