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Giant Sunflower

Helianthus giganteus

Last reviewed: October 2026

Helianthus giganteus, or Indian-potato, is a tall forb found in wet meadows and moist prairies across the eastern and midwestern United States, blooming yellow from July through September in full sun and medium to wet soil.

Giant Sunflower (Helianthus giganteus)
Photo: Wikimedia Commons (Public domain)

Toxicity unknown

Giant Sunflower (Helianthus giganteus) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

Light

full sun

Water

medium

Size

36"–96" H × 12"–24" W

Bloom

Jul, Aug, Sep

Native to

DE, GA, IA, IL and 18 more states

Pollinators

bees, butterflies, beetles

Before you buy

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Browse plants for this ecoregion

PiedmontNorthern Glaciated PlainsWestern Corn Belt PlainsGreat PlainsNorthern Lakes and ForestsNorth Central Hardwood ForestsDriftless AreaSoutheastern Wisconsin Till PlainsCentral Corn Belt PlainsEastern Corn Belt PlainsSouthern Michigan/Northern Indiana Drift PlainsHuron/Erie Lake PlainsNortheastern HighlandsNortheastern Coastal ZoneErie Drift PlainMiddle Atlantic Coastal PlainNorthern PiedmontSoutheastern PlainsBlue RidgeRidge and ValleyCentral AppalachiansWestern Allegheny PlateauMississippi Valley Loess PlainsAtlantic Coastal Pine Barrens

Indian-potato is a tall native sunflower that produces bright yellow blooms from summer into early fall. This perennial spreads slowly to form colonies and can reach up to 8 feet tall, making it an impressive backdrop plant. The flowers attract numerous pollinators and provide seeds for birds in autumn.

Growing Giant Sunflower

Grow Giant Sunflower in full sun and medium water. Mature plants reach 36 to 96 inches tall and spread 12 to 24 inches wide. Expect low maintenance to keep it looking intentional in a front yard.

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In an HOA neighborhood

Giant Sunflower takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.

Works well in: backyard only.

  • Extremely tall height appears wild and unmanaged
  • Can look weedy when dormant
  • Spreading habit may appear unkempt

Wildlife value

Supports bees, butterflies, and beetles with nectar and pollen throughout its long blooming period. Seeds provide important food for goldfinches and other birds in fall and winter.

Common questions

When does Helianthus giganteus bloom?
Indian-potato typically flowers from July through September, producing clusters of bright yellow blooms atop tall stems.
What pollinators visit Indian-potato flowers?
Bees, butterflies, and beetles commonly visit Helianthus giganteus for nectar and pollen during its summer bloom period.
How much water does Helianthus giganteus need?
This species grows best in medium to consistently moist soil and is often found along wet meadows, ditches, and low prairie edges.
How tall does Indian-potato grow?
Helianthus giganteus is one of the taller sunflower species, frequently reaching six to twelve feet under good growing conditions.
What growing conditions suit this plant best?
Full sun paired with medium to wet soil, such as in open meadows or moist prairie sites, gives this forb its strongest growth and bloom.
Is Giant Sunflower HOA-friendly?
Giant Sunflower takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.

Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

If something looks wrong

Common plant problems, and what to check first

These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.

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