Hope you can help me out. I planted this white coneflw.

last fall.

It has flowered with black stripes making the plant look horrible. Don't know if it's diseased or what.

It has gotten more black as time goes on.

What can I do to correct this.

Will it happen again next year?

Thanks for listening.

Thought I could send u a picture. sorry I hope my info is enough to solve this problem.