Echinacea purpurea 'Magnus' Purple Coneflower Size: 2 to 5' high by 18 to 24" wide. Hardiness: Zones 3 to 9. Heat Zones: 9 to 1. Habit: The sturdy plants produce coarse, toothed, dark green leaves and stiffly upright flowerstalks that are topped with huge pincushion-like coppery cones surrounded by usually drooping petals. Culture: Full Sun to light shade.