they don't really talk about how envious this plant really is of being green do they?
Try and move this one in the fall to a place that gets more shade then other coneflowers. The sun will bleach this one to a gray/purple/blah before the flower even completely opens... so you never seen the two colors.
here is mine from a spring bloom.. which held it's color for less then a week before it looked like a normal purple coneflower. I am going to move mine again to an even more shaded location.
Good advice...mine have been in 60% shade for the past decade and bloom well each year. I think the important thing is mine were raised from divisions, not seeds. As a grower, I find most of the newer hybrids do not remain true if grown from seed and often revert in second and third generation to the native species.
Your Green Envy may be a third generation reversion...which too often occurs in our market today...buyers have created a 'rush to sell' which often results in short supplies and short-cuts on sales...as well as inadequate field testing.
I have a large area of 30+ Green Envy. The only reversion -- return to dominent pink -- is from the natural seedlings that occur in that portion of the bed...only one out of 30 or so second generation seedlings have proven to maintain the bi-coloration...and it reverted this year (3rd) to complete pink.
As to the rust, I have never experienced it on coneflowers. It is usually in the dna of the plant, but it could also be inadequate air flow...they will take the breezes.
I am sorry you have had poor luck with this particular plant...I love it and so do the butterflies! LOL
Seeds from any of the new hybrids won't match the parent.. or it's genetically a very slim change... you might get something interesting.. though a majority of the time it will be like a standard purple.
The actual hybrid plant itself though can't revert back to a purple plant. Many times if you buy a hybrid... a seed can fall to the crown. The next year you get standard seedlings grown mixed in the grown with no blooms. By the third year they do bloom and it appears as though it's reverted. And many times the standards outgrow the hybrids which have a shorter lifespan anyway.
Here are some of the odd ball blooms i have gotten from seed over the past few years of seeding tons of hybrid plant seeds.
Even the oddball blooms are nice and interesting though, ever tried cuttings from any of them that had enough stem?
They spider looks like a few of the hybrids, is that near what cross pollinated with that stem bloom?
It is late but, I am trying a few Pow Wow Wild Berry from seed, Maybe they will stay or be true, I have read here they are the only hybrid that grows true from seed.