Giant Sunflower
Helianthus giganteus
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Asteraceae
- Genus:
- Helianthus
- Species:
- Helianthus giganteus
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb
- Height:
- 12-20 ft
- Light Requirements:
- Full Sun
- Drought Tolerance:
- High
- Bloom Months:
- jul, aug, sep
- Bloom Colors:
- Yellow
Native Range
United States: Alabama, Connecticut, District of Columbia, Delaware, Georgia, Iowa, Illinois, Indiana, Kentucky, Massachusetts, Maryland, Maine, Michigan, Minnesota, Mississippi, North Carolina, New Jersey, New York, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, Vermont, Wisconsin, West Virginia, Canada: Alberta, Manitoba, New Brunswick, Nova Scotia, Ontario, Quebec
Keystone Species Ranking
- Caterpillar Keystone:
- ★★☆☆☆ Based on number of butterfly and moth species using this genus as host plant (Source: National Wildlife Federation)
- Bee Keystone:
- ★☆☆☆☆ Based on number of native bee species using this genus for pollen and nectar (Source: National Wildlife Federation)
Host Plant for Caterpillars
Cremastobombycia ignota, Eucosma sombreana, Gnorimoschema ambrosiaeella, ⚠️maritime borer moth (Papaipema maritima), ⚠️Papaipema necopina (Papaipema necopina)
Reported Fauna Sightings
Bees: Brown-belted bumble bee (Bombus griseocollis), Brown-belted bumble bee (Bombus griseocollis), Common eastern bumble bee (Bombus impatiens), Common eastern bumble bee (Bombus impatiens), Confusing bumble bee (Bombus perplexus), Confusing bumble bee (Bombus perplexus), Half-black bumble bee (Bombus vagans), Half-black bumble bee (Bombus vagans), Lemon cuckoo bumble bee (Bombus citrinus), Lemon cuckoo bumble bee (Bombus citrinus), Northern amber bumble bee (Bombus borealis), Northern amber bumble bee (Bombus borealis), Sanderson bumble bee (Bombus sandersoni), Sanderson bumble bee (Bombus sandersoni), Tri-colored bumble bee (Bombus ternarius), Tri-colored bumble bee (Bombus ternarius)
Soil Requirements
- Soil Type:
- moist, rich, well-drained loamy soil
- pH:
- 5.5 - 7.0 (slightly acidic to neutral)
- Drainage:
- tolerates poor drainage
- Moisture:
- consistently moist
- Notes:
- prefers wet meadows and marshy areas
Germination Information
Pre-treatment: Single-step cold-moist stratification for temperate woodland species. for 60–120 days
Source: OpenAI GPT-4o