[Helianthus pauciflorus subsp. subrhomboideus X H. tuberosus] Showy Sunflower Asteraceae:
A very large and showy species. This North American native sunflower has many bright yellow flowers that have dark black centers. Plants grow from 4 to 8 feet tall and bloom in late summer, after flowering is done the seeds are feed upon by migrating birds. Best in dry, sandy or loamy soils even doing well in clay soils. Drought tolerant. Should be given plenty of room to spread-out, plants have spreading underground rhizomes that will enlarge the plant each year. Grow with other large sun loving perennials in the back of a mixed border or use has a mass planting along a fence or in amongst a collection of large ornamental grasses. A very useful plant for a garden used to attract wildlife, such as birds and insects.
Cover seeds and use 45-55F, with germination starting in 5 to 24 days and spread out over many weeks. If little germination move to 27-39F for 6 weeks.