Yellow coneflower, Echinacea paradoxa, is native to limestone glades in the Ozarks in Missouri and Arkansas. Its paradox is that this is the only species in the “purple coneflower” genus that doesn’t have purple flowers – at least until the more brightly-colored E. purpurea hybrids were developed recently. E. paradoxa was a key contributor in breeding programs for those new coneflower cultivars such as the  Meadowbrite™ series and others.
E. paradoxa is sometimes confused with Ratibida pinnata (prairie coneflower, grayhead coneflower), which also sometimes has the common name of yellow coneflower but these are completely different plants.

Both have reflexed yellow ray flowers surrounding a dark center, but the latter has pinnate leaves and a much taller central cone than E. paradoxa does. Also called Ozark coneflower, or Bush’s purple coneflower, E. paradoxa has a deep taproot to allow it to survive its very dry native conditions but it is also quite content in humus-rich garden soil. This perennial grows well throughout most of the mid-western and eastern US, being hardy in zones 3 to 9.

This species blooms in early summer. It produces large single blossoms, each 6” or more across. The drooping bright yellow to yellow-orange ray flowers surround a chocolate brown bristly center on the ends of tall, lanky stems. Blooms are surprisingly fragrant and make good cut flowers. Butterflies, bees and other insects frequent the flowers when in bloom and small seed-eating birds, such as goldfinches, feed on the seeds in the fall.

The smooth, dark green leaves are long and linear with linear veining. The foliage grows about 18” tall but the flower stems grow much taller, up to 36” in height.
Use yellow coneflower individually in the border or as a mass planting. Because it has an open habit, it is best to plant this species in groups of 3 or more in the garden to increase the visual impact. Try combining it with bright red or purple bee balm (Monarda), Teucrium ‘Purple Tails’, or blue-flowering catmint (Nepeta). Plant in front of tall ornamental grasses, such as little bluestem (Schizacryium scoparium) or ‘Karl Foerster’ feather reed grass (Calamagrostis x acutiflora).

Interplanting with other sturdy-stemmed plants may help support the plants, which have a tendancy to flop. Yellow coneflower also fits well in a native plant garden, naturalized area, prairie or wildflower meadow.
Plant yellow coneflower in full sun in ordinary garden soil. Once established, it is drought-tolerant and requires little maintenance. E. paradoxa has few problems and is considered deer resistant.
Yellow coneflower is propagated from seed or division. Seed germination is improved by cold moist stratification.

The easiest way to achieve this would be to plant outside in the fall for spring germination. Otherwise, mix seeds with equal amounts or more of damp sand or vermiculite. Place in a sealed plastic bag and store in the refrigerator for 1-2 months. Some seeds may sprout in the storage bag if moist stratified too long.
It requires several growing seasons for yellow coneflower to reach its full size. Most plants do not bloom until their second or third year from seed, and it generally takes about 5 years before you get a good flower show. Because it develops a tap root, put in a permanent location when young or transplant when dormant in the early spring or late fall.
– Susan Mahr, University of Wisconsin – Madison