Scientific Name:
Helianthus annuus
cvs.
Pronunciation:
hee-lee-AN-thus ANN-you-uss
Common Name:
sunflower
Family Name:
Asteraceae
Plant Type:
Annual, Flowering cut plant, Flowering pot plant
Key ID Features:
Stems commonly 1-3m tall, hairy; leaves alternate, broadly ovate, 10-40cm long x 5-35cm wide, sandpapery texture, margin coarsely toothed, petioles 2-20cm long; flower heads large, most 7-15cm wide, dark brown to purple disc florets and yellow to orange ray florets (often used to depict the sun); achenes 5-12mm long, tan with black lengthwise stripes.
Habit:
Upright
Form:
Oval - vertical
Texture:
Coarse
Mature Height:
2 - 3m
Mature Spread:
1.0 - 1.5m
Growth Rate:
Fast
Origin:
Garden origin, North America
Hardiness Rating:
Zone 9: (-7 to -1 °C)
Exposure:
Full sun
Soil/Growing Medium:
Well-drained
Water Use:
Moderate
Landscape Uses:
Attract beneficial insects, Attract birds, Bedding plant, Container planting, Cut flower or foliage, Dried flower or fruit, Fall interest, Floristry, Herb, Medicinal plant, Perennial border, Summer interest, Urban agriculture, Wildlife food
Additional Info:
Google. Cultivars shown may include H. 'Big Smile' and H. 'Velvet Queen' (red flower heads). Compare to H. giganteus.
Leaf Morphology:
Form:
Simple
Arrangement:
Alternate
Texture/Venation:
Soft flexible, Pinnate venation
Surfaces:
Rugose, Pubescent
Colour in Fall:
Green-yellow
Shapes:
Ovate
Apices:
Acute
Bases:
Cordate, Obtuse
Margins:
Ciliate, Dentate
Inflorescence Type:
Head (capitulum), Floriferous
Flower Morphology:
Flowers perfect
Corolla Shape:
Ligulate
Ovary Position:
Inferior
Colour (petals):
Showy, White, Orange, Yellow, Red, Dark-red (cv. 'Big Smile' is yellow and cv. 'Velvet Queen' is red)
Flower Scent:
None
Flower Time at Peak:
Jul, Aug, Sep, Oct
Additional Info:
Cultivar on left is Helianthus annus 'Big Smile'
Fruit Type:
Achene, Edible
Fruit Colour:
Brown
Fruiting Time:
Oct, Nov
Additional Info:
Not showy, Edible
Bark or Stem Colour:
Green
Organ Modifications:
Storage tap root
Propagation:
Seed
Maintenance:
Medium
Other:
Staking may be required for tall cultivars
Pest Susceptibility:
Fungal leaf spot, Rust (Disease resistant, Rabbit resistant, Drought tolerant)
Specific Pests:
Deer
