Rhododendron reticulatum ("Kobanomitsubatsutsuji")

Japanese name: コバノミツバツツジ （小葉三葉躑躅）
Scientific name: Rhododendron reticulatum

[Overview]
A deciduous shrub 1.5–3 m tall, found in coppice woodland.
Young branches are at first densely covered with long pale brown hairs.
The leaves are simple, borne 3 at a time in a whorl-like arrangement at the branch tips, elliptic to broadly ovate, 3–5 cm long and 1.5–3 cm wide.
On young leaves, long pale brown hairs grow on the upper surface.
On the underside, a fine net-like pattern of veins is conspicuous.
The leaf margin has fine serrations ending in hairs.
The petiole is 0.3–0.5 cm long.
It flowers before the leaves unfold or almost at the same time as they open, with 1–2 flowers at each branch tip.
The flowers are reddish purple and 3 cm across, and the corolla is funnel-shaped with 5 lobes.
There are dark spots on the inner surface of the upper side of the corolla.
There are 10 stamens, of differing lengths.
The fruit is a capsule densely covered with brown bristles or long grayish-white hairs.

[Cultivation]
Propagate from seed.
The rooting rate is very 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.
Pests and diseases include spider mites, azalea lace bugs and Benimon-aoringa.

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