An herbaceous perennial, the majestic Echinacea won't bloom until its second year of maturity. It will reseed but I prefer to start in pots or when I dig up the plants for root medicine, I'll divide and transplant immediately, or transfer to pots. Echinacea prefers full sun but will tolerate a bit of afternoon shade in the heat of summer. Medium water and space plants 12-18" apart.
I've read that the roots contain the strongest medicine. However, my 25-year herb farmer veteran believes the white pith of the flower head has the strongest medicine. Either way, all parts of the plant are used for medicine. In the third year you can dig up the root but be sure to leave a clump to produce a new plant the following year. Flowers and leaves are harvest annually when the plant is most robust and healthy, usually in late August.
Drying roots takes some time, maybe a week. Wash and clean them well, chop them up into smaller pieces and lay flat to dry in a warmer dehydrator around 115-120 f. If not dried thoroughly they will mold so check them daily for a week after storage to make sure they are completely dry. The flower head, stock and stem, also take some time, perhaps a week in a moderate low and slow drying condition, 95-105 F for five days to a week. The petals and leaves will dry in about 24-48 hours. Store them in sealed plastic containers in a dark, dry cool location for up to three years.
Echinacea tincture is a very common way to preserve this medicine and a convenient way to consume it; only as need, at the onset of a cold or flu and not for more than two weeks. You can also infuse the herb in oil, honey, or vinegar, or in water for a tea. Echinacea herbal actions include; alterative, lymphagogue, anti-inflammatory, vulnerary, immunostimulant, antimutagenic, and sialagogue.