Osteospermum (genus)

Japanese name: オステオスペルマム
Scientific name: Osteospermum

[Overview]
The genus ranges from annuals to shrubs, but those sold in Japan are perennials.
The leaves are usually alternate, either deeply pinnately divided or oblong to spatulate with entire margins.
Flower heads are borne at the stem tips, solitary or in umbel-like to corymb-like arrangements.
The ray florets around the flower head are white, purple, pink and so on, and set seed.
The central tubular florets are yellow, purple and so on, and do not set seed.
The involucre consists of 1–3 rows.
The flowers open in fine weather and close when it is cloudy and at night.
The fruit is an achene without pappus.
It closely resembles Dimorphotheca and is distinguished by the number of involucral bracts and the fertility of the tubular florets, but because hybrid cultivars of the two exist, telling them apart is difficult.

[Cultivation]
Propagate from seed or by stem cuttings.
It can overwinter outdoors in regions without frost.
It prefers fertile soil with plenty of sun, good drainage and good aeration.
Be careful not to let it become too wet; for potted plants, water thoroughly when the soil surface dries, and for plants in the ground, rainfall is sufficient.
During long rainy spells, it is better to move potted plants out of the rain.
In spring and autumn, apply slow-release fertilizer placed on the soil.
Remove spent flowers and dead leaves promptly.
After the spring flowers finish, cutting back to 1/2–1/3 of the height makes it easier to get through summer.
Pests and diseases include gray mold and aphids.

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