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Helianthus giganteus (Giant sunflower)
Bransford, W.D. and Dolphia

Helianthus giganteus L.

Giant sunflower

Asteraceae (Aster Family)

USDA Symbol: hegi

USDA Native Status: Native to U.S.

As the name suggests, giant sunflower is a large, showy plant.A tall, rough, reddish stem bearing several to many light yellow flower heads. The branched, purplish stem grows to 10 ft. tall and bears terminal, yellow flowers.

Despite this plants names, its flower heads are comparatively small; the common and species names actually refer to the plants overall height.

 

From the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Flower:
Fruit:
Size Class: 3-6 ft.

Bloom Information

Bloom Color: Yellow
Bloom Time: Jul , Aug , Sep

Distribution

USA: CT , DC , DE , GA , IA , IL , IN , KY , MA , MD , ME , MI , MN , MS , NC , NJ , NY , OH , PA , SC , TN , VA , VT , WI , WV
Canada: MB , NS , ON , SK
Native Distribution: NY & Ont. to MN, s. to GA & KY; naturalized northeastward
Native Habitat: Moist places; marshes
USDA Native Status: L48(N), CAN(N)

Growing Conditions

Light Requirement: Sun
Soil Moisture: Moist , Wet
Soil Description: Moist soils
Conditions Comments: Not Available

Benefit

Use Wildlife: Seed heads attract birds.
Warning: The stems and leaves can cause skin irritation in humans. The plant can be fatal to animals if ingested. Humans should generally avoid ingesting plants that are toxic to animals.
Conspicuous Flowers: yes

Value to Beneficial Insects

Special Value to Native Bees

This information was provided by the Pollinator Program at The Xerces Society for Invertebrate Conservation.

Propagation

Description: Excellent germination occurs with seeds that have been refrigerated over winter. Stem cuttings can be taken before flowering, but the easiest method of increase in to divide the clump in early spring.
Seed Collection: Nutlets usually mature 2-3 weeks after flowering. To beat finched to the seeds, secure a small bag around seeds heads after the flowers fade. Air-dry collected seed heads, separate nutlets from chaff, and store in sealed, refrigerated containers.
Seed Treatment: Not Available
Commercially Avail: yes

Find Seed or Plants

Find seed sources for this species at the Native Seed Network.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is either on display or available from the following:

Native Seed Network - Corvallis, OR

Recommended Species Lists

Find native plant species by state. Each list contains commercially available species suitable for gardens and planned landscapes. Once you have selected a collection, you can browse the collection or search within it using the combination search.

View Recommended Species page

Additional resources

USDA: Find Helianthus giganteus in USDA Plants
FNA: Find Helianthus giganteus in the Flora of North America (if available)
Google: Search Google for Helianthus giganteus

Metadata

Record Modified: 2007-01-01
Research By: TWC Staff

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