I have a number of coneflowers: Double Decker have had for 4+ years, grows well but has never gotten a double flower. Sundown doing well. Green Jewel doing well. Hot Papaya looked bad at first but is looking much better now, did the same last year too. Marmalade, died after first year and replaced it last year, looks okay so far this year, hope it increases a little. Harvest Moon, have had that for 5 years or longer stays in a nice neat little clump. Pink Double Delight, have had for several years, by the second year it increased into a large beautiful clump. Vintage Wine, died after first year and replaced it last year. It looks okay so far. White Mist, have had for 4+ years stays in a small but beautiful clump. Coconut Lime, 4+ years, does very well and stays true to color. Green Jewel, 4+ years doing well, however, pretty sure it has reseeded itself (even though I try to avoid that), I get a variety of colors from it now. Fancy Frills remains a small clump over the years, is always the very last to bloom. White Swan is no longer white, became a light pink with a few almost white petals. PowWow Wild Berry does great. PowWow White struggles. New to my gardens this year are, Solar Flare and Avalanche. Regarding seeds: I'm no expert by a long shot but I too have heard the seeds from these hybrids won't come back "true". I tested it, by sowing seeds in the fall, (with Twilight) and it grew to look like the standard purple coneflower only quite a bit shorter. Hot Papaya reseeded itself and surprisingly it looked very much like the original...maybe just a little lighter in color and a little shorter.
