What’s the problem?
My kalanchoe plant’s leaves have developed a strange white, powdery coating, and I’m worried it may spread.
Diagnosis
This sounds like powdery mildew, a common fungal disease. It thrives in warm, humid environments with poor airflow. Powdery mildew doesn’t usually kill a plant outright, but it weakens growth, damages leaves and can spread quickly to nearby plants.
Prescription
Start by isolating the affected plant to prevent the fungus from spreading. Remove any heavily infected leaves carefully. Improve airflow by opening a window often or using a fan. Treat the remaining leaves with a natural antifungal spray: mix one teaspoon of baking soda with a litre of water and a drop of castile soap. Spray the plant weekly until the mildew clears. For more stubborn infections, apply neem oil or use a store-bought fungicide.
Prevention
Make sure not to overcrowd your plants and maintain good air circulation, particularly around succulents. Check them regularly, especially during the cooler months, to identify early signs of fungal activity.
