Sprinkle the coneflower seeds on one-half of the paper towel. Fold the towel in half so the seeds are between two layers of moist towel. Seal the towel in a plastic bag and keep it in the refrigerator for eight to 12 weeks. This cold treatment mimics winter conditions and helps the seeds break dormancy so they can germinate.

Prep the Pots
Fill 8-inch-deep seedling pots with moistened potting soil. Coneflowers need extra-deep pots because they develop very long taproots.

Sow the Seeds
Sow two coneflower seeds in each pot, covering them with only a thin sprinkling of soil, and allow the pots to drain.

Cover the Pots
Cover the pots with clear plastic to retain moisture and keep the pots in a warm room to germinate.

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blooming period for coneflowers is between June and October

These should be planted in spring or early summer. Coneflowers can be started from seed in spring indoors (about a month before the last spring frost date) or outdoors (when the soil temperature has reached at least 65°F/18°C). Note: Coneflowers started from seed may take 2 to 3 years before producing blooms.

https://www.almanac.com/plant/coneflowers