Rhododendron Halopeanum'

Rhododendron ‘Halopeanum’, also sold under the name ‘White Pearl’, is a large evergreen rhododendron for gardens with acidic, well-drained soil. Its opulent and bright late spring flowering and its vigour make this bush an excellent choice for creating a tall hedge or a flowering screen. Good heat tolerance and respectable hardiness complete these qualities.

This rhododendron belongs to the Ericaceae family. It is an old hybrid obtained in Normandy: seedlings harvested in 1885 near Cherbourg by Mr. Halopé flowered in 1893, with the hybrid being presented in 1896; the name ‘Halopeanum’ is the Latinisation of the breeder's surname. The parents are Rhododendron griffithianum and R. arboreum. The bush is also widely distributed under the horticultural synonym ‘White Pearl’.
Of vigorous habit, it becomes tree-like with age, with rapid growth in favourable soil. In open ground, the plant reaches 4 to 6 m in height, or even more in an oceanic climate. At 10 years, it measures 1.70 m to 1.80 m in height with a width of about 1.20 m. The brown-grey bark is decorative on old specimens with twisted branches. The stems are robust, branching from the base; the plant does not sucker, but can self-layer directly beneath low branches. The root system is shallow and fibrous, typical of rhododendrons.
Flowering occurs in May. Deep pink buds open into large, funnel-shaped, white corollas with a pink blush when fully open, spotted with crimson red in the throat and with crinkled edges. The conical inflorescences consist of 9 to 12 flowers and can be lightly scented. The evergreen foliage is made up of broad, ovate to oblong, lustrous dark green, leathery leaves on short petioles.

To accommodate this large rhododendron 'Halopeanum' in your garden, you will need space and an acidic, humus-bearing, well-drained but moist soil; choose a location in partial shade or gentle sun, sheltered from the wind. This variety fits into a tall screen at the back of the garden, in an informal hedge, or as a specimen near a lawn. You can associate it with other acid-loving bushes: Camellia japonica ‘Nuccio’s Gem’ for its white winter flowering and glossy foliage, Magnolia soulangeana ‘Lennei’ for its spring flowers, Pieris japonica ‘Forest Flame’ for its colourful young shoots and Rhododendron luteum for its very fragrant yellow spring flowering.

Geographical origin of the parent species: Rhododendron griffithianum is Himalayan (Nepal to Myanmar), and R. arboreum is widespread in the Himalayas and peninsular India; their cross-breeding explains the vigour and size of ‘Halopeanum’. It is one of the oldest European hybrids of rhododendron, still cultivated in large arboretums; some historic specimens reach the size of a small tree and are listed as "remarkable trees" in public collections.