My plants are dying. The roots are drying. Curry patta plant started with white powdery substance all over stems and twigs. And then I cut the entire thing; now even other plants are getting same problem and dying.
Areca Palms Are Dying of Some White Powdery Disease
Certified GKH Gardening Expert
Your problem is powdery mildew, which is a fungus. Here is an article or two that you may find helpful: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/answers-to-what-causes-hibiscus-leaves-turning-yellow.htm