A humidity level of 45% is recommended for the polka dot begonia. When your plant is in warm and dry conditions for too long, the mildew develops. However, the plant will still thrive with higher humidity levels. Powdery Mildew Multiple fungal pathogens can cause powdery mildew on begonias. Older leaves that rapidly become yellow are a clear sign of over-watering, usually caused by too little light, with other symptoms include mouldy or heavy soil, stunted growth and a rotten base. Maculata can grow up to 60 inches or 1.5 meters in height. Pick any heavily infested leaves from the begonia and destroy them. This exotic plant derives its name from its unique silver spotted leaves and red undersides. Keep temperatures between 67 to 70°F with high … I know, I probably should have quarantined the new plant, but we live and learn I suppose. Clusters of angelic white flowers enhance the beauty of this peep in the warm days of spring and summer. Begonia maculata is another houseplant that has taken the plant world by storm and is super popular. My Begonia Maculata Wightii was sitting next to my Begonia China Curl. However, the begonia maculata is prone to powdery mildew that would compromise the beauty of the plant. The leaves will turn yellow and dry up. Although mildew is ugly and can disfigure your begonia, the chances are good that the plant won’t die. Each mature leaf can grow in the range of 20 to 25 cm in size. This is different than other fungal diseases. Powdery mildew, or Oidium begoniae, appears on begonia leaves as a white powder or powdery looking spots. Begonia Maculata Flowers. This disease appears as powdery white spots on both leaf surfaces, stems and … The disease covers your plant’s leaves with dusty mildewy spots. Your Begonia Pavonina has a Powdery Mildew . I have started to see reddened spots on the China Curl, so I believe I need to treat this one for powdery mildew and leaf spot as well. Begonia Maculata commonly referred to as the Polka dot Begonia, is undoubtedly one of the most strikingly gorgeous species of indoor plants. Care for Begonia Maculata houseplant: Begonia maculata is a plant that needs indirect bright light, like to thrive in temperature between 18 degrees C to 30 degrees C, fertilize one in a month, normal humidity range is enough, easy to propagate and regular pruning is required. Although Begonia can do well in darker locations, the frequency of irrigations must be reduced to counteract the chance of root rot. Leaves. A humidifier would be the ideal way to maintain the right humidity levels around the plant. The Begonia Maculata does well in a potting mix with good drainage using a soil mix with sand and clay. Common Issues with Begonia Maculata. This will cause rotting to occur and also invite various diseases that begonias can be prone to including powdery mildew, among others. Powdery mildew on your Begonia pavonina happens.