Hibiscus moscheutos (rose mallow, "Amerikafuyo")

Japanese name: アメリカフヨウ
Scientific name: Hibiscus moscheutos

[Overview]
A perennial 1–1.8 m tall, growing wild in wetlands and along rivers.
The leaves are simple and alternate, ovate to broadly lanceolate, 20 cm long and less than half as wide; they are usually undivided, but may occasionally be very shallowly palmately divided into 3–5 lobes.
The underside of the leaves has soft white hairs, and the margins are toothed.
The leaf stalks are long.
The flowers are borne singly in the upper leaf axils of the stem; they have 5 white to pink petals, 10–16 cm across, and some have a dark crimson center.
The staminal column does not protrude beyond the flower.
The calyx is 1.8–4 cm long, with the tube and lobes of almost the same length.
The bracteoles are 1.5–2.5 cm long, shorter than the calyx, linear-lanceolate, and number 10–14.
Each flower opens in the morning and wilts by evening, lasting only one day.
The fruit is an almost spherical capsule about 2.2–3 cm long, containing many seeds.
The seeds are 2.3–2.8 mm long, hairless, and somewhat rough.

[Cultivation]
Propagate from seed or by division.
The optimum germination temperature is a high 25°C.
It prefers sunny, moist soil that is well drained, retains water well and is rich in humus.
It is a plant of damp places, so extremely dry sites are unsuitable.
In winter, cut the dead stems at ground level and protect the plant from cold with mounded soil or a straw mulch.
For potted plants, take care not to let the soil dry out, and from spring to autumn water when the soil surface has dried.
Apply compost around the base of the plant in winter, and apply slow-release fertilizer as additional fertilizer in early summer.
Prune in winter when the leaves have fallen.
In regions where the leaves fall in winter, it is good to cut it back hard to near the base and protect it from cold with mulch or similar.
Pests include aphids and leaf rollers.

[Notes]
The plants sold in Japan as Amerika-fuyo are hybrid groups made by crossing this species with Momiji-aoi (Hibiscus coccineus) or Sokobeni-aoi (H. militaris), and they bear huge flowers 20–30 cm across.
Garden varieties derived directly from this species are also sometimes collectively called "Amerika-fuyo."

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