Helianthus annuus /ˌhiːliːˈænθəs/
Common name: Sunflower
Helianthus annuus , the common sunflower, is a large annual plant in the daisy family, Asteraceae, native to North America. Each 'flower' is actually a composite head made up of hundreds of tiny disk florets surrounded by yellow ray florets. Sunflowers are grown worldwide for their edible seeds, oil, and as ornamentals.
Care summary
Sun
Full sun, 6–8+ hours daily
Water
Moderate; drought-tolerant once established
Soil
Fertile, well-draining, near-neutral
Hardiness
Grown as annual in all zones
Mature height
1.5–3.5 m (5–12 ft), taller in giants
Pet safe
Non-toxic to pets
Difficulty
Easy
Propagation
Grown from seed sown directly where it is to flower. Sow seeds about 2 cm deep in full sun after the last frost and keep moist until germination, which takes one to two weeks. Sunflowers dislike transplanting, so direct sowing is best.
Fun facts
- A sunflower head is not one flower but a composite of up to 2,000 tiny individual florets.
- Young sunflower buds track the sun across the sky, a behavior called heliotropism; mature heads face east.
- The tallest sunflower on record reached 9.17 m (30 ft 1 in) in Germany in 2014.
- Sunflowers were first domesticated by Indigenous peoples of North America around 4,000–5,000 years ago.