Helianthus argophyllus (silverleaf sunflower, "Shirotaehimawari")

Japanese name: シロタエヒマワリ （白妙向日葵）
Scientific name: Helianthus argophyllus

[Overview]
An annual growing 1–2 m tall, sometimes even 3 m.
The whole plant is covered with soft white silky hairs and looks whitish.
The stem is erect and branches in the upper part.
Leaves are simple and alternate, ovate, 15–25 cm long and 10–20 cm wide, with margins that are slightly serrated or entire.
There is a petiole.
Flower heads 7.5–10 cm across are borne at the branch tips, 1–5 per plant.
The head consists of ray flowers and tubular flowers; the ray flowers around the edge are yellow and number 15–20.
The tubular flowers clustered in the center number more than 150 and are reddish dark brown.
The fruit is an achene.

[Cultivation]
Propagate from seed.
It prefers fertile soil that is sunny, well drained and well aerated, but in its native range it grows on sandy or poor ground near the coast, so it grows well in most places that are sunny and well drained.
For potted plants, water thoroughly when the soil surface dries.
For plants in the ground, rainfall is sufficient.
If basal fertilizer is applied, no further fertilizing is particularly necessary.
Pests and diseases include aphids and spider mites.

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