The purple coneflower (Echinacea purpurea) is one of my favorite flowers; it's easy to grow, cheap, spreads quickly (giving me lots of new plants to spread around) and looks good over a long season (I leave the seedheads up for the birds).
I so fell in love with purple coneflower that I planted other types as well, White swan, some of the Big Sky hybrids, and others.
I bought and planted in the spring, in well-draining loamy soil and full sun (watering them in, and appropriately until established), fed only early in the season with Osmocote giving them an opportunity to establish. To my disappointment, none of the newer varieties came back more than for one additional season (except for White Swan, which has done well.
I decided that either I know a lot less about gardening than I thought I did, the new echinaceas are weak, or maybe both.
Has anyone else had success with the newer echinaceas? Are some better than others? At this point, I don't even know why they're labeled as perennials.
Can anyone tell me why I am incapable of keeping the newer varieties? I am in zone 6b, but my microclimate is probably more like zone 6.