My Basil plants have this black mildew/powdery substance under some of their...
My Basil plants have this black mildew/powdery substance under some of their leaves. What is it? It wipes off easily. Can I still sell it at the farmers market? Is it still safe to eat?
Washington County Minnesota
It sounds like you are describing basil downy mildew. Here is a publication: http://www.extension.umn.edu/garden/yard-garden/vegetables/basil-downy-mildew/
The MN Department of Agriculture considers this to be a serious disease - it can wipe out entire crops. And, while it wipes off easily, I am not sure I would be comfortable selling this basil even after it appears to wipe off easily. These plants should be destroyed to help reduce the spread of the disease.