Rhododendron Yedoense or Korean Azalea
This deciduous shrub (listed also as Rhododendron poukhanense) is native to Korea and Japan where it is also widely cultivated in parks and gardens. It grows to a height of only 1 to 1.5m (3 to 5 ft) and has purplish-lilac, very fragrant, which appear in May. In harsher climates the blossoms may be damaged by frost. The variety yodogawa has semi-double flowers and is semi-deciduous.
The Korean azalea has given rise to several garden forms distinguished by the bright or glowing colour of their blooms. The former division of the genus into deciduous species (azaleas) and evergreen species doubtless had something in its favour from the horticultural viewpoint, for azaleas differ in many ways from the evergreen rhododendrons, first of all in their requirements as regards location. Azaleas are tolerant of drier soils but require aerated, nourishingwith good . They do not need to be shaded or sheltered by other plants, in fact they do best in a sunny situation where they bear the greatest profusion of flowers.
Azaleas also differ from evergreen rhododendrons in their period of flowering, which is usually earlier, sometimes as early as the end of April, but generally May, and in cold, exposed positions the flowers may be damaged by frost. Azalea blossoms need not be pinched out after they have faded, as the shrubs lose nothing of their flower-bearing properties the following year if they are not removed.