Thinleaf Sunflower
Helianthus decapetalus
- Native to:
- Canada, United States, Virgin Islands
iNaturalist: © abelkinser (iNaturalist #240805171)
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:
- 180 cm
- Light Requirements:
- Full Sun,Part Shade,Shade
- Drought Tolerance:
- Low
- Bloom Months:
- jul,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:
- birds, butterflies, bees
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; sow in spring or fall.