I've grown Zinnias before but never had this problem until last year and now its this year too. What is into my zinnias-- purple, deformed stems, curling stems, sad blooms? I am not an experienced gardener. I shook some Sevin dust but didn't do much. I've thrown out two plants already which seemed to be dying.

Help?? Thank you, Katherine
I live in Woodruff, SC, not far from Spartanburg.