I noticed that two of my scabiosa plants have white mildew and two next to them do not. We have had a great deal of rain this year and it is my understanding that scabiosas do not like too much moisture however why only two plants are affected? What advise can you offer? Thank you, Christina
Certified GKH Gardening Expert
Sounds like a case of Powdery Mildew.
This article will help you.