The name helianthus is from the Greek "helias" meaning sun and "anthos" flower. Members of the aster family, these natives are commonly called sunflowers.
They are usually tall, often coarse plants with daisy like yellow and gold flowers. The flowers are borne from summer through to the fall, and the petals surround dense centers of disk florets which produce the seeds.
In Your Garden
Pinch the plants in early and mid summer to produce breaching and reduce height.
There are both annuals and perennials, and the perennials should be divided every 3-4 years.
Helianthus multiflorus is, as its name suggest, a many flowered sun flower, and I especially like the refined double flowered cultivar "Flora Plens," which has a dahlia type flower and grows well in my zone 5 garden.
The thin leaved lemony yellow sunflower ‘decapetalus' grows much taller and more aggressively in my garden and has single daisy type flowers with yellow centers.
I love it for its wealth of golden flowers, which fill my vases from mid summer to mid fall.
The sun comes down into the garden when these flowers bloom.