Genus: Sunflower

Helianthus

Photo/Illustration: 
Michelle Gervais
Sunflower (Helianthus)
hee-lee-AN-thus
Asteraceae
This genus contains annuals and perennials native to North, Central, and South America. Sunflowers are generally coarse plants with simple, bristly leaves. Their showy flowers are daisy-shaped and, thanks to many cultivars, come in shades of yellow, orange, red, cream, purple, and bronze.
Noteworthy characteristics:  Showy, daisy-shaped flowers in a vast array of sunny colors, forms, and sizes. Good in borders, annual beds, cutting gardens, and wildlife plantings.
Care:  Sunflowers need full sun and fertile, moist but well-drained soil. They flower best during long, hot summers. Most will tolerate drier conditions, but some species thrive in moist soil. Stake if needed.
Propagation: 

Sow seeds of annuals in late winter indoors or in situ in spring. Sow seeds of perennials in a cold frame in spring. Divide perennials in spring or fall or root basal cuttings in spring.

Problems: 

Downy mildew, powdery mildew, canker, rust, and fungal leaf spots are common. Be on the lookout also for caterpillars, cutworms, beetles, and weevils.

Species, varieties and clutivars for genus Helianthus

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Swamp sunflower
Helianthus angustifolius
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Sunflower
Helianthus annuus and cvs.
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Branching sunflower
Helianthus debilis
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Woodland sunflower
Helianthus divaricatus
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Sawtooth sunflower
Helianthus grosse-serratus