Zinnia Problem

Zinnia Problem

Something is happening to my zinnias and it's happening fast. What was a problem on just one flower the other day is quickly taking over my zinnia flower bed. Can anyone help me identify what's going on? Photobucket It starts at the leaves like this.. Photobucket and ends up doing this to the flowers. I suspect the white stuff might be powdery mildew, but I'm not sure. I don't know about the brown spots. Does anyone know how to organically treat this problem (I have an all organic garden)? Thank you.
Saving money in the garden

Saving money in the garden

two plant ids

two plant ids

Plant ID question

Plant ID question

Pics of the living room.

Pics of the living room.

New 2 Bedroom Apartment

New 2 Bedroom Apartment

Potatoes, Sunflowers and a question

Potatoes, Sunflowers and a question