Leaves dry and brown, flowers small
I live in Southern Michigan. I have my black eyed susan plants planted on the south side. Water every other day. The plants grew to maturity nicely, but seemed to be late blooming. Then noticed the leaves became dry and crumbly with a brown color, as well as the flowers being small. Other plants around are not affected this way and are growing great!
Submitted by BHGPhotoContest

It sounds as though your black-eyed susans developed a fungal leafspot disease. They are quite drought tolerant, and should not need water more than once per week. Wet foliage and high humidity can promote disease development. Next year, try cutting back on the frequency of watering (but soak the soil thoroughly when you do water). Avoid wetting the foliage as you water; apply the water directly to the soil instead.

Answered by BHGgardenEditors