Rhododendron kaempferi var. kaempferi ("Yamatsutsuji")

Japanese name: ヤマツツジ （山躑躅）
Scientific name: Rhododendron kaempferi var. kaempferi

[Overview]
A semi-evergreen shrub 1–5 m tall, found in forests at low elevations in the mountains.
Young branches and petioles are densely covered with pale brown stiff hairs.
There are two types of leaves, spring leaves and summer leaves, both simple and alternate.
Spring leaves are 2–5 cm long and 0.7–3 cm wide, variable in size and shape, with long hairs on both sides, especially dense on the veins of the underside.
Summer leaves are lanceolate to oblong, 1–2 cm long and 0.4 cm wide.
The petiole is 0.1–0.3 cm long.
There are 1–3 flowers at the branch tips.
The flowers are vermilion and 3–4 cm across, with a funnel-shaped corolla that is 5-lobed.
There are dark spots on the inner surface of the upper side of the corolla.
There are 5 stamens.
The fruit is a capsule densely covered with brown long hairs.

[Cultivation]
Propagate from seed.
Cuttings are also possible, although the rooting rate is very poor.
It prefers fertile, acidic soil that is sunny, well drained and moisture-retentive.
Avoid dry sites, or mulch to keep the base of the plant from drying out.
For potted plants, it is best placed from spring to autumn in partial shade out of the afternoon sun and direct summer sunlight, and from autumn to spring in a sunny spot protected from cold wind; in the ground, a spot in the shade of deciduous trees is good.
For potted plants, water thoroughly when the soil surface dries from autumn to spring, and in midsummer water twice a day, in the cool of morning and evening, wetting the leaves as well.
For plants in the ground, rainfall is sufficient except in summer; in summer, water in the cool of morning or evening so that the leaves are wetted too, and in winter, if dry weather continues, water in the morning on a warm day.
Apply fertilizer three times in total, in winter, after flowering as thanks fertilizer, and in autumn, using organic fertilizer or a slow-release chemical fertilizer with equal amounts of the three main components, around the plant.
Do not prune; just adjust the shape of the tree by removing excess buds in early summer after flowering.
Remove spent flowers promptly.
Pests and diseases include spider mites, azalea lace bugs and Hypomecis-type moths (Benimon-aoringa).

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