we have purple coneflowers that produce a green ball for the flower but no petals. Is this thrips and what can I do about it?
Howard County Maryland flowers: annuals and herbaceous perennials
Would you be able to send us photos of the flowers? There is a condition called aster yellows, a virus-like pathogen, that can cause purple coneflowers to be deformed and exhibit bizarre tufts of deformed leaves inside the flower heads. A similar symptom can be caused by eriophyid mite feeding. You can find additional information (and photos for comparison) here: http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advi...
Our specialists viewed your photos. We cannot say for sure what you are dealing with. It could be either aster yellows or mite feeding. The best recommendation is to remove the affected plants and place in the trash.