Caladiums, often called “Angel Wings” or “Heart of Jesus” plants, are cherished for their vibrant, colorful foliage. While stunning, their leaves can sometimes turn yellow. This article explains common reasons for yellowing caladium leaves and how to address them.
Normal Yellowing Versus Problematic Yellowing
Distinguishing between natural processes and actual problems is important when observing yellowing caladium leaves. A few older leaves yellowing and dying off is a normal part of the plant’s growth cycle, especially as new foliage emerges, allowing the plant to redirect energy.
Caladiums are tuberous plants that naturally enter a dormant period, typically in cooler months. During dormancy, all leaves yellow and die back, which is normal. However, extensive yellowing outside these natural cycles usually indicates an underlying environmental stressor or health issue.
Key Causes of Caladium Leaf Yellowing and How to Address Them
Watering Problems
Improper watering frequently causes yellowing leaves. Both overwatering and underwatering lead to distress. Overwatering saturates the soil, depriving roots of oxygen and leading to root rot, which manifests as mushy stems and overall yellowing. Conversely, underwatering causes leaves to droop, develop crispy edges, and yellow due to dehydration.
To correct overwatering, ensure adequate drainage and allow the top 1-2 inches of soil to dry between waterings. For underwatered plants, water thoroughly until water drains from the bottom, then maintain consistent moisture without sogginess.
Light Issues
Caladiums thrive in bright, indirect light. Direct sun can scorch delicate leaves, causing yellowing, browning, or holes. Too little light results in pale, leggy growth and general yellowing because the plant cannot photosynthesize efficiently.
Relocate your caladium to a spot with filtered sunlight, such as a north or east-facing window indoors. Outdoors, place them in a shaded area with dappled light. If indoor lighting is insufficient, consider supplementing with a grow light.
Nutrient Deficiencies
A lack of essential nutrients can cause caladium leaves to yellow. Nitrogen deficiency typically results in older, lower leaves turning pale green and then yellow. Magnesium deficiency often presents as interveinal chlorosis, where areas between leaf veins yellow while veins remain green. Iron deficiency also causes interveinal yellowing, but usually appears first on younger leaves.
Regular fertilization during the growing season can address these deficiencies. Apply a balanced liquid fertilizer every two to three weeks, or use a quarter-strength controlled-release fertilizer. Ensure the soil is rich and well-draining to support nutrient uptake.
Temperature and Humidity Stress
Caladiums are tropical plants that prefer warm, humid conditions. Temperatures below 60°F (15°C) or above 85°F (29°C) can cause stress, leading to yellowing or browning of leaves. Low humidity, especially in dry indoor environments, can make leaf tips turn brown and crispy before yellowing.
Maintain daytime temperatures between 70-75°F (21-23°C) and nighttime temperatures around 60-65°F (15-18°C). To increase humidity, group plants, use a pebble tray with water, or employ a humidifier. Avoid cold drafts and sudden temperature fluctuations.
Pests and Diseases
Pests and diseases can contribute to yellowing leaves as a symptom of damage or infection. Common pests like spider mites, aphids, and mealybugs feed on plant sap, causing discoloration and distorted growth. Fungal diseases such as root rot (often from overwatering) or leaf spot can also lead to yellowing, wilting, and brown spots.
Regularly inspect your caladiums, especially leaf undersides, for signs of pests. Treat mild infestations with insecticidal soap or neem oil. For fungal issues, improve air circulation, avoid overhead watering, and remove affected leaves. If root rot is suspected, remove the plant, trim rotten roots, and repot in fresh, well-draining soil.
Maintaining Healthy Caladiums
Proactive care prevents yellowing leaves and ensures caladiums thrive. Consistent attention to their environmental needs helps maintain vibrant foliage. A well-draining potting mix is foundational for healthy root development and preventing water-related issues.
Keep the soil consistently moist, but never waterlogged, by checking moisture before watering. Ensure the plant receives bright, indirect light, moving it away from harsh direct sun that can damage leaves. Maintaining high ambient humidity (ideally 60-80%) through humidifiers or pebble trays supports lush growth. Regular, but not excessive, fertilization during the growing season provides necessary nutrients.