Answer: Purple coneflower (Echinacea) usually needs to be 3-4 years old before dividing. However, the crown of your plant sounds large enough to be divided; you can dig and divide it this fall.
Echinacea seed is colored tan or two-toned tan and brown. The echinacea seed varies substantially in size and density, depending on the species and especially depending on the availability of water and nutrients during the growing season. An ounce of seed contains anywhere from 6,000 to 7,500 seeds, and given the right conditions germination is usually around 80%. A period of cold, moist conditioning (stratification) will improve germination rate on most species. Natural outdoor stratification is much more successful than artificial (refrigerated) stratification. Sow the seed directly in the garden or field in the fall or early spring. Barely cover the seed and tamp in. Keep weeded and thin to between 6 inches to 1 foot apart (for the taprooted species), and 2 feet apart for Echinacea purpurea.
Q&A Library Searching Tips