Thinleaf Sunflower

Helianthus decapetalus

Native to:
Canada, United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Asteraceae
Genus:
Helianthus
Species:
Helianthus decapetalus
USDA Symbol:
HEDE

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb
Height:
150 cm
Light Requirements:
Full Sun,Part Shade,Shade
Drought Tolerance:
Medium
Bloom Months:
aug,sep,oct
Bloom Colors:
yellow

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)
Butterflies & Moths:
★☆☆☆☆ Documented Lepidoptera association (GBIF)
Caterpillars:
★★☆☆☆ Recorded caterpillar host plant (HOSTS Database)

Keystone Species Ranking

Caterpillar Keystone:
★★★★☆ Butterfly & moth species supported by this genus (NWF)
Pollen Specialist Bee Keystone:
★★★★★ Native pollen specialist bee species supported by this genus (NWF)

Host Plant for Caterpillars

Bucculatrix fusicola, corn earworm (Helicoverpa zea), Eucosma sombreana, Giant leopard moth (Hypercompe scribonia), juniper pug (Eupithecia pusillata), Omiodes Leafroller (Omiodes simialis), Rigid Borer Moth (Papaipema rigida), Suleima cinerodorsana, Charidryas gorgone, orange oakleaf (Charidryas nycteis)

Reported Fauna Sightings

Bees: Common eastern (Bombus impatiens)

Garden & Ecology Notes

Wildlife Value:
bees, butterflies, birds, small mammals
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Resprouts vigorously from rhizomes after fire; typical of woodland edge species in fire-maintained systems.

Soil Requirements

Soil Type:
rich, well-drained loamy soil
pH:
5.5 - 7.0 (slightly acidic to neutral)
Drainage:
good drainage preferred
Moisture:
consistently moist
Notes:
prefers fertile soils in woodland areas

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
14–30 days
Notes:
Seeds germinate readily after cold stratification. Light may improve germination rates.

The above propagation data sourced from Claude AI