What are alpine rhododendrons, Rhododendron hybridum, and foreign rhododendrons?

Scientific name: Rhododendronhybridum

Aliases: Rhododendron hybridum, foreign rhododendron

Family and genus: Ericaceae, Rhododendron

Morphological characteristics:

The alpine wintergreen is an evergreen shrub, about 20 cm tall, growing on mid- to high-altitude mountains. The leaves are oblanceolate, smooth on the surface, with serrated edges, and alternate. The stems are red, erect or growing along the ground.

The leaves are clustered at the branch tips, hairless on the leaf surface, with dense reddish-yellow woolly hairs on the underside. The flowers are terminal, in racemose umbellate inflorescences, with bell-shaped corollas in colors such as white, pink, and red, and fleshy calyxes that wrap around the fruit after fruiting. There are ten stamens and a five-locular ovary. The fruit matures from July to October and is a capsule. A single flower bud contains more than a dozen small flowers, opening in a spherical shape, with vivid colors, and the flowering period is from April to May.

The plant is full, with large leaves and beautiful, unique flowers.

Growth habits:

The alpine rhododendron has strong adaptability and can grow at normal temperatures. In Europe, it is mostly produced outdoors, and where conditions permit, it can be produced in greenhouses.

It grows on shady mountain slopes, in alpine fir forests, or on grassy slopes at forest edges at an altitude of 2500 to 4000 m.

Alpine rhododendrons are now mostly used for potted ornamental display. They prefer cool, humid environments, and because the crown is large, the water requirement is also large. The root system is well developed, and it is a shallow-rooted tree species. The growing medium should be loose, rich in humus, and have good soil aggregate structure, with a pH value between 5.5 and 6.5. Planting in clay tile pots is best.

Alpine rhododendrons are not tolerant of high temperatures and grow poorly above 35°C, but they can withstand severe cold of -10°C. Proper acidity is the guarantee for their robust growth. They can overwinter safely in Jiangnan regions such as Shanghai, Wuxi, and Suzhou.

Management:

In spring, autumn, and winter, alpine rhododendrons grow very vigorously, and management is also relatively extensive.

Rhododendrons are universally recognized as precious ornamental flowers and are one of China's top ten famous flowers, with extremely high ornamental and economic value.

Alpine rhododendrons are a major category within the rich rhododendron resources. They are cultivated varieties developed through more than a hundred years of hybridization from three major subgenera: the lepidote rhododendron subgenus, the elepidote rhododendron subgenus, and the evergreen rhododendrons in the subgenus Azaleastrum.

On the one hand, because of their huge racemose umbellate inflorescences (usually 15-20 cm, with some varieties reaching more than 25 cm), vivid colors, graceful flower forms, and beautiful plant shapes, they are deeply loved by people and have become recognized as high-grade potted flowers.

On the other hand, they have strong adaptability, especially being able to withstand low temperatures of -26°C without dropping leaves, remaining evergreen through all four seasons, and requiring no special facilities. They are not only beloved Lunar New Year flowers, but also excellent varieties for urban and rural greening and beautification.