Hi Alandale ... would you happen to be able to post some photos? Last year, lots of my plants had come down with asters yellows, so many rudbeckias were struck that I hadn't even bothered to pull them out. Though, this year, only one plant was hit and I discarded it early in the season.

Terrance

I'm not an expert, but my own ech purpurea grew funny this year - stems grew whorly and never shot up or bloomed. I snapped off the offending stems late in July and now new growth seems normal, but so late in the season I won't have a chance to see the blooms to decide if I should remove the plant.

Seems like if it is aster yellows, that virus will remain in the roots to come back the following year. A mite could cause symptoms similar to A/Y's, please check the link below. Also recommend you hop over to the perennial form and do a search there. Many posters are from warmer zones, but lots of info on the echinacea and it's problems. Many have dug up large collections due to yellow asters. So very sad. Darn those sucking insects (aphids, leafhoppers) for spreading this!

Best wishes to your garden.

Here is a link that might be useful: Echinacea diseases

Thank you both for your replies. Coincidentally while I was taking pics to post here, a kindly neighbour who's been gardening all his life, stopped by and said "You should really pull those plants out dear. They've got aster yellows." I had to laugh although it will be a bit depressing actually yanking them out. I just hope I haven't waited too long. I guess I'll find out next year. It's been a challenging gardening season what with those wretched scarlet lily beetles finally hitting this area, an awful spring, and now this disease. Oh well, on the positive side I now have space to try something new. That doesn't happen often. Cheers and happy gardening!