Thinleaf Sunflower
Helianthus decapetalus
- Native to:
- Canada, United States
sonnia hill





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