Purple Coneflower - 2, one gallon plants Your order will consist of 2, one gallon Purple Coneflower plants. Echinacea purpurea 'Magnus' or Purple Coneflower should be grown in full sun to light shade. Light shade will enhance the rich colors of the petals in hot weather. Purple coneflower 'Magnus' has broad non-drooping petals of rosy purple surrounding a dark cone.