Kalanchoe plants are popular houseplants, appreciated for their vibrant blooms and succulent foliage. Yellowing leaves are a common concern for many Kalanchoe owners. Understanding the reasons behind this discoloration is the first step toward restoring your plant’s health. This guide identifies the causes of yellowing leaves and provides solutions.
Understanding Why Kalanchoe Leaves Turn Yellow
Both overwatering and underwatering can cause Kalanchoe leaves to yellow, with distinct symptoms. Overwatering often leads to mushy or translucent yellow leaves, sometimes with a softened stem. Underwatered leaves typically turn yellow and become crispy, often starting from the tips or edges.
Light exposure plays a significant role in Kalanchoe leaf health. Too much direct sunlight can scorch the leaves, causing yellow or brown patches. Conversely, insufficient light can also result in pale, yellowing leaves as the plant struggles to produce chlorophyll. Kalanchoes generally thrive in bright, indirect light.
Nutrient deficiencies can cause yellowing leaves. A lack of nitrogen often causes older, lower leaves to turn uniformly yellow. Magnesium deficiency appears as yellowing between the veins, with veins remaining green. Iron deficiency typically affects younger leaves, causing them to yellow while veins stay green.
Extreme temperatures can stress Kalanchoe plants, leading to leaf discoloration. Cold drafts or temperatures below 50°F (10°C) can cause leaves to yellow, wilt, and drop. Prolonged exposure to hot conditions, especially with inadequate watering, can also induce yellowing from heat stress.
Pests and diseases can contribute to yellowing foliage. Sap-sucking insects like spider mites, aphids, or mealybugs can drain the plant’s vitality, leading to yellow spots or overall yellowing. Fungal diseases, such as root rot from excessive moisture, can also lead to widespread yellowing and wilting as the root system becomes compromised.
Yellowing leaves can also be a natural part of the Kalanchoe’s life cycle. As the plant matures, older leaves, typically at the base, will naturally yellow and drop off. This process is normal and usually does not indicate a serious problem if only a few bottom leaves are affected.
Diagnosing and Treating Yellowing Kalanchoe Leaves
- Adjust watering practices. Allow the top 1-2 inches (2.5-5 cm) of soil to dry completely before watering. Water thoroughly until it drains from the pot bottom, then empty any excess from the saucer to prevent root rot.
- Optimize light conditions. If leaves appear scorched, move the plant to bright, indirect sunlight. If leaves are pale and uniformly yellow, it may need more light; relocate it to a brighter spot, avoiding intense afternoon sun.
- Address nutrient needs by fertilizing during the growing season. Use a balanced, water-soluble fertilizer diluted to half strength every 2-4 weeks in spring and summer. If a specific deficiency is suspected, a soil test can confirm it for targeted application, but general houseplant fertilizer often suffices.
- Manage temperature fluctuations. Keep your Kalanchoe in a stable environment between 60-75°F (15-24°C). Protect plants from cold drafts from windows or air conditioning vents, and avoid placing them near heat sources.
- Identify and treat pests with regular inspection of leaves and stems. If pests are present, use insecticidal soap or neem oil spray, following product instructions. For fungal issues like root rot, repot into fresh, well-draining soil and adjust watering habits.
- Recognize natural leaf drop. If only the lowest leaves are yellowing and the rest of the plant appears healthy, simply remove the yellowed leaves. This helps the plant redirect energy to new growth and maintain vigor.
Ongoing Kalanchoe Care for Healthy Growth
Maintain healthy Kalanchoe plants with an appropriate potting mix. A well-draining succulent or cactus mix is ideal, preventing waterlogging and promoting healthy root development. Repotting every 1-2 years into a slightly larger pot with fresh soil refreshes the plant’s growing environment.
Proper air circulation around the plant prevents fungal issues that can lead to yellowing. Avoid overcrowding plants, allowing sufficient space for air to move freely around the foliage. This reduces humidity around leaves and stems, creating a less hospitable environment for pathogens.
Consistent care routines, including regular inspection, prevent problems before they become severe. Periodically check the top and undersides of leaves for signs of discoloration or pests. Early detection allows for timely intervention, preventing minor issues from escalating into significant health problems.