Good Morning Helen, 

Thank you for contacting the U of M Extension Service. 

Please click on the following link: https://extension.umn.edu/plant-diseases/gray-mold-flower-garden

This information discusses gray mold, wilting leaves and spots on the leaves. 

Here is another link that discusses powdery mildew: https://extension.umn.edu/plant-diseases/powdery-mildew-flower-garden

From viewing your photos, the third photo which has oddly shaped blooms might have aster yellows: 

https://extension.umn.edu/plant-diseases/aster-yellows

Please read through the aster yellows information. If you decide your plant has aster yellows, in this case, you need to remove the plant. 

The rain and cool weather has been hard on plants. 

Good Luck!