Rhododendron weyrichii var. weyrichii ("Ontsutsuji")

Japanese name: オンツツジ （雄躑躅）
Scientific name: Rhododendron weyrichii var. weyrichii

[Overview]
A deciduous shrub or small tree 3–6 m tall, found mainly at the edges of forests in low mountains.
It is sometimes found on ridges and rocky places in mountains at an elevation of about 1,000 m.
Dense pale brown hairs grow on the young branches and leaf stalks.
Leaves are simple, borne in threes in a whorl-like arrangement at the branch tips, rhombic-circular to ovate-circular, 5–9 cm long and 4–6 cm wide, with a sharply pointed tip.
Young leaves have long hairs on both sides, but later become hairless except along the main vein on the upper surface and the veins on the underside.
It usually flowers at the same time as the leaves unfold, with 1–3 flowers at the branch tips.
The flowers are vermilion, rarely reddish purple, 4–5 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 uneven length.
The fruit is a distorted cylindrical capsule densely covered with long brown hairs.

[Cultivation]
Propagate from seed.
Cuttings are also possible, although the rooting rate is very poor.
It prefers sunny, well-drained, moisture-retentive, fertile acidic soil.
Avoid dry sites, or mulch to keep the base of the plant from drying out.
For potted plants, place them in partial shade out of the afternoon sun and direct summer sunlight from spring to autumn, and in a sunny place sheltered from cold wind from autumn to spring; for plants in the ground, a spot shaded by 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 morning and evening, so that the water also reaches the leaves.
For plants in the ground, rainfall is sufficient except in summer; in summer, water in the cool morning or evening so that the water also reaches the leaves, and in winter, if dry weather continues, water in the morning on a warm day.
Fertilize three times in total, in winter, after flowering as a thank-you fertilizer, and in autumn, applying an organic fertilizer or a slow-release chemical fertilizer with equal amounts of the three components around the plant.
Do not prune; just remove excess buds in early summer after flowering to tidy the shape.
Remove spent flowers promptly.
Pests and diseases include spider mites, azalea lace bugs and Benimon-aoringa.

[Notes]
The Japanese name comes from the plant being large overall.

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