From my perspective, the first sign of trouble is often a subtle change. A faint, white, powdery film begins to appear on my leaves, starting small on one or two before spreading. This is the powdery mildew, a fungal parasite, landing on me and starting to feed. It feels like a suffocating blanket, blocking my stomata—the tiny pores I use to breathe and transpire. I cannot photosynthesize efficiently. My growth becomes stunted, and my beautiful, plump leaves may start to yellow, distort, or even drop prematurely if the infection is severe. Other fungal issues, like botrytis or black spot, present as dark, mushy, or sunken lesions, often a sign of too much moisture around my roots or in my crown.
You must understand that I am a succulent, built for arid, sunny environments with excellent air circulation. The conditions that make this fungal attack possible are often not my ideal ones. High humidity, poor air flow, and crowded conditions among my fellow plants create a perfect breeding ground for these spores. Overhead watering is particularly stressful; when water sits on my leaves in cool, still conditions, it gives the fungal spores the moisture they need to germinate and invade my tissues. Weak light makes me less resilient and contributes to the dampness they love.
If you see the signs, the very first thing you must do for me is to isolate me from my plant companions. Fungal spores are airborne and can travel easily, putting everyone at risk. Move me to a warm, dry, and well-ventilated area with plenty of bright, indirect light. Please refrain from watering me until you are sure the soil is completely dry. This creates an environment that is hostile to the fungus and gives me a fighting chance. Carefully remove any severely infected leaves that are more than 50% covered or are mushy, disposing of them far away from other plants.
For the powdery mildew on my remaining leaves, you can create a gentle spray. A mixture of one part milk to two parts water can be effective; the compounds in milk are antagonistic to the mildew. Alternatively, a solution of one tablespoon of baking soda, half a teaspoon of liquid soap, and one gallon of water can alter the pH on my leaf surface, making it inhospitable. Please test any spray on a single leaf first to ensure it does not damage my farina—my precious powdery coating. For more serious or persistent infections, a fungicide containing potassium bicarbonate or a biological fungicide with Bacillus subtilis can be applied, following the product instructions carefully. Most importantly, correct my living conditions: ensure I have strong light, fantastic air flow, and that you water me only at the soil level when my soil is completely dry.
