Lulstraat 3, 9770 Kruishoutem
HARDY GHENT AZALEA
What are deciduous azaleas?
These plants have nothing at all in common with the familiar indoor azaleas, but belong to the genus Rhododendron subgenus Pentanthera. They are shrubs originating from temperate regions, primarily in North America, but some are also from Southeast Asia, Japan and Southeast Europe. In the nineteenth century these species (varieties occurring in the wild) formed the basis for the hardy Ghent azalea, with “hardy” meaning that these species are well able to withstand winter.
R. luteum: The only European azalea is R. luteum, which originated from the European Caucasus to the northeast of Lithuania and Poland and came to the west in around 1793; a common name for this plant is “azalea pontica”.
The fragrant yellow flowers bloom in early May before the emergence of the leaves.
R. calendulaceum: Originating from the east coast of North America and cultivated in Europe around 1800, this plant is called the “Flame azalea” in America on account of its fiery orange colour; the flowers open only after the development of the leaves, around the end of May
R. periclymenoides: This plant is found in America from South Carolina to Tennessee, and in Virginia and New England. The light pink or purple/pink fragrant flowers appear in early May, before the leaves appear.
R. viscosum: Occurs in the eastern states of the USA (Maine, Massachusetts, Connecticut) and in North and South Carolina, Ohio, Tennessee and Louisiana. This azalea likes moist soils and is known in America as the “Swamp azalea”. The white fragrant flowers only bloom in early July, after the emergence of the leaves.
R. prinophyllum: Also known as “azalea nudiflora rosea” and found in the state of New York. This plant was introduced to Europe around 1812 as “azalea rosea”.
The fragrant pink flowers usually emerge at the same time as the leaves.
R. canescens: From the southeast of the USA. This plant can be recognised by the dense hair on the leaves and buds.
The fragrant white to purple or red flowers develop in early May, or at the same time as the leaves.
R. flameum: From the southeast of the USA, especially Georgia and South Carolina. The flowers blossom in May at the same time as the leaves, the colour varies from orange to red.
R. occidentale: Occurs along the west coast of North America. The flowers are usually white with yellow spotting in the throat, very fragrant, blooms late May / early June.
R. molle: Also called Rhododendron sinensis, originates in central and eastern China. The main feature of this plant is that the flowers bloom before the development of the leaves; the yellow flowers are more open and wider than R. luteum; a green spotting is visible in the throat.
R. molle japonicum: Originates in Japan, from Kyushu to Hokkaido. This plant is closely related to the previous species, but is much hardier. The yellow, pink, red or orange flowers bloom in May.
In addition to these species which formed the basis for the development of the “Hardy Ghent”, there some other deciduous rhododendron species which make very interesting garden plants:
R. canadense: Originates in Canada, Newfoundland, Labrador and the northeast USA.
Remarkably beautiful autumn colouration of the leaves, the plants with purple/pink flowers change to a bluish purple, while the variety with white flowers change to yellow.
The flowers are rather small, but striking and bloom relatively early in April - May.
R. vaseyi: Its natural habitat is limited to North Carolina.
The flowers, which are white to pink with a greenish spotting in the throat, bloom in April - May.
This plant likes an aerated but moist soil.
R. schlippenbachii: Found mainly in Korea. The white to pink lightly fragrant flowers appear at the same time as the young leaves in May. The obovate leaves are very striking and only gradually fall from the plant when the new young leaves appear.