Rhododendron (genus, "Shakunage")

Japanese name: シャクナゲ （石南花、石楠花）
Scientific name: Rhododendron

[Overview]
An evergreen shrub.
The leaves are simple and alternate, clustered at the branch tips, and brown hairs grow on the undersides.
Funnel-shaped flowers bloom in clusters at the branch tips.
There are many cultivars.

[Cultivation]
Propagate by cuttings or grafting.
It prefers well-drained, well-ventilated, fertile acidic soil.
Avoid dry places, or use mulch or similar to prevent the base of the plant from drying out.
From spring to autumn it is best placed in partial shade out of the afternoon sun and direct summer sunlight, and from autumn to spring in a sunny spot sheltered from cold wind; in the ground, a place shaded by deciduous trees is good.
For potted plants, from autumn to spring water thoroughly when the soil surface dries, and in midsummer water twice, in the cooler 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 cooler morning or evening so that the water also reaches the leaves, and in winter, if dry weather continues, water in the morning of a warm day.
Apply fertilizer a total of three times: in winter, as thanks fertilizer after flowering, and in autumn, placing organic fertilizer or slow-release compound fertilizer with equal amounts of the three components around the plant.
Do not prune; instead shape the tree by rubbing off buds in spring to early summer.
Remove spent flowers frequently.
Pests and diseases include root rot, gray mold, brown spot, flower blight (sclerotinia), pestalotia disease, aphids, scale insects, leafrollers, armyworms and shoot borers.

View this page in Japanese (日本語)