Rhododendron quinquefolium ("Shiroyashio")

Japanese name: シロヤシオ （白八入）
Scientific name: Rhododendron quinquefolium

[Overview]
A small deciduous tree 3–6 m tall, found at forest edges in deep mountains.
Young branches are hairless and reddish brown.
The leaves are simple, borne 5 at a time in a whorl-like arrangement at the branch tips, rhombic to ovate-rhombic, 2–5 cm long and 1.5–3 cm wide, with short hairs on the midrib of the upper surface and dense soft hairs at the base of the underside.
The leaf margin has long hairs.
The petiole is 0.1–0.2 cm long.
It flowers as the leaves unfold, with 1–2 flowers at each branch tip.
The flowers are white and 3–4 cm across, and the corolla is broadly funnel-shaped with 5 lobes.
There are 10 stamens.
A green blotched pattern appears on the inner surface of the upper side of the corolla.
The fruit is a lopsided cylindrical capsule and is hairless.

[Cultivation]
Propagate from seed.
The rooting rate is poor, but cuttings are also possible.
It prefers fertile acidic soil that is sunny, well drained and retains water well.
Avoid dry sites, or prevent the base of the plant from drying out by mulching or similar means.
Potted plants are best placed in partial shade out of afternoon sun and direct summer sunlight from spring to autumn, and in a sunny place sheltered from cold wind from autumn to spring; plants in the ground are best in a place shaded by deciduous trees.
For potted plants, water thoroughly when the soil surface dries in autumn to spring, and in midsummer water twice, in the cool morning and evening, so that the leaves are also wetted.
For plants in the ground, rainfall is sufficient except in summer; in summer, water in the cool morning or evening so that the leaves are also wetted, and in winter, if dry weather continues, water in the morning of a warm day.
Apply fertilizer three times in total: fertilizer in winter, fertilizer after flowering as thanks to the plant, and in autumn, placing organic fertilizer or slow-release chemical fertilizer with equal amounts of the three components around the plant.
Do not prune; at most, thin the buds in early summer after flowering to tidy the shape.
Remove spent flowers frequently.

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