Hi there - looking for an answer. Planted the white echinacea and the leaves went black. The plant wasn't too healthy to start with, but wondered if my new amended soil was just a trifle too rich. I did ask the guy who brought the rotted manure and top soil (all mixed in) whether the manure was really aged and it certainly looked like it. Do you think the manure burnt the roots? No other shrub or plant seems to be affected - yet!! Thanks guys!
Would you like some 'white swan' echinacea seed? It's very very easy to grow from seed. I am an organic gardener & this is a disease resistant strain. I haven't havested the seed yet, but it's out on the plant if you want some. Just email me & I'll get a SASE from you.
Byorn, could you describe this disease a little more and what can be done about it? I've been fighting something similar, may be the same thing. I'm especially concerned about a big pot of oleander. I've pruned it back very heavily, but some of the remaining leaves still have a few black spots on them. I'm into the hardwood part of the plant, the softwood stems had black spots on them, so they had to go, flowers and all. :o(