Share

Native Plant Database

Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

Search native plant database:
Name:    
Family:    

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

Helianthus giganteus

Helianthus giganteus L.

Giant sunflower

Asteraceae (Aster Family)

Synonym(s): Helianthus alienus, Helianthus borealis, Helianthus giganteus ssp. alienus, Helianthus giganteus var. subtuberosus, Helianthus nuttallii var. subtuberosus, Helianthus subtuberosus, Helianthus validus

USDA Symbol: HEGI

USDA Native Status: L48 (N), CAN (N)

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.

 

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

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

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

Value to Beneficial Insects

Special Value to Native Bees

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

Find Seed or Plants

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

National Wetland Indicator Status

Region:AGCPAKAWCBEMPGPHIMWNCNEWMVE
Status: FACW FACW FAC FACW FACW
This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

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

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

Go back