Purple coneflower (echinacea purpurea) is a perennial that is most commonly propagated by seed. This attractive flower exhibits a golden cone center, surrounded by pink, purple or lavender petals. The purple coneflower will grow as tall as 4 feet, but it usually reaches anywhere from 1 to 3 feet high. The purple coneflower does best in USDA hardiness zones of 4 through 10. It prefers full sun to partly sunny locations with fertile, well-drained soil.
Perform a pH test on the soil where you intend to plant the purple coneflower seeds, using a soil pH tester available at your local garden center. Purple coneflowers prefer an acidic, slightly alkaline soil with a pH of 6.
Loosen the soil with a shovel or a spade to a depth of 18 inches. Add lime and sulfur amendments to the soil, as indicated by the pH tests, and rake into the planting bed.
Press the purple coneflower seeds into the bed with your finger at a depth of ... inch. They do not need to be planted very deep, as they often grow in the wild from scattered seeds. Space the seeds 18 to 24 inches apart.
Water the seeds immediately, and keep slightly moist during germination. This process will take between 15 and 30 days.