It seems leaf spot and powdery mildew have taken over my zinnia flower bed. In just a week, over half of my flowers have been affected. Most of the leaves are covered in spots and/or mildew and now blooms are dying.
Are there successful organic treatments for these? I think the leaf spot happened first and the mildew took over because the flowers were weakened.
My area has had a pretty wet, mild spring, so I think this has contributed to the problem.