Rhododendron radendum belongs to the Ericaceae family. It prefers cool, moist, and sunny environments. It is cold-resistant and shade-tolerant, but cannot withstand prolonged exposure to strong sunlight.
The ideal temperature for its growth is between 15 to 28 degrees Celsius, and it can withstand temperatures as low as -8 degrees Celsius in winter. It is an evergreen or semi-evergreen shrub that can grow up to 3 meters tall.
It has sparse branches and young branches covered in light brown flat hairs. The leaves are papery, elliptical to lanceolate or rectangular-elliptical, measuring 2.5 to 5.6 cm in length and 8 to 18 mm in width.
The apex is sharply pointed with a prominent tip, and the base is wedge-shaped. Initially, there are scattered yellow hairs, but later the upper surface becomes nearly hairless. The leaves have a blunt tip and a wedge-shaped base, with ciliate margins.
The petioles are hairy, measuring 4 to 6 mm in length. Both the upper and lower surfaces of the leaves are hairy, with the midrib being the hairiest. In autumn, the leaves become narrow and elongated, resembling inverted egg shapes or elliptical-lanceolate shapes, and they are thick and glossy.
Evergreen or semi-evergreen shrub, growing up to 3 meters tall, with sparse branches and young branches covered in light brown flat hairs.
The leaves are papery, elliptical to lanceolate or rectangular-elliptical, measuring 2.5 to 5.6 cm in length and 8 to 18 mm in width. The apex is sharply pointed with a prominent tip, and the base is wedge-shaped.
Initially, there are scattered yellow hairs, but later the upper surface becomes nearly hairless. The leaves have a blunt tip and a wedge-shaped base, with ciliate margins. The petioles are hairy, measuring 4 to 6 mm in length.
Both the upper and lower surfaces of the leaves are hairy, with the midrib being the hairiest. In autumn, the leaves become narrow and elongated, resembling inverted egg shapes or elliptical-lanceolate shapes, and they are thick and glossy.
Flowers, 2 to 3 in number, emerge from the top bud of new shoots. The corolla is rose-red to bright red, with a dense red spot on the upper petal. The flowers are wheel-shaped, with a diameter of about 4.5 to 7 cm.
There are 5 stamens, with yellow anthers. The sepals are small and ovate, light green in color, and covered in fine hairs. The fruit is ovate, measuring 0.6 to 0.7 cm in length. The flowering period is from April to May.
The flowers, 1 to 3 in number, are borne on the terminal branches. The peduncles are 6 to 12 mm long, covered in slightly spreading reddish-brown flat hairs. The calyx is large, deeply divided into 5 lobes, with each lobe measuring about 8 mm in length.
The margins are serrated and have long cilia, and the outer surface is covered in the same hairs. The corolla is wide and funnel-shaped, with a diameter of about 6 cm.
There are 5 lobes, wide-ovate in shape, and deep purple in color, with dark purple spots. There are 10 stamens, with the lower part of the filaments being hairy, and the ovary has dense rough hairs, while the style is hairless.
The fruit is rectangular-ovate in shape, measuring about 8 mm in length, and has rough hairs and persistent sepals. Traditional cultivars include “Yu Hudie” (Jade Butterfly), “Zi Hudie” (Purple Butterfly), “Liuqiu Hong” (Ryukyu Red), and “Yu Ling” (Jade Bell).
Azaleas prefer cool, moist, and sunny environments. They are cold-resistant and shade-tolerant, but cannot withstand prolonged exposure to strong sunlight.
The ideal temperature for their growth is between 15 to 28 degrees Celsius, and they can withstand temperatures as low as -8 degrees Celsius in winter. They thrive in fertile, well-drained, acidic sandy loam soil.
Cultivated in various regions.
When planted in clusters, azaleas create a vibrant and colorful display during their flowering period, adding to the natural landscape effect of gardens.
They can also be planted in clusters near rocks, by ponds, or along the edges of lawns to enhance the atmosphere of the garden. When potted, they can be placed in hotels, living spaces, and public areas, creating a stunning and eye-catching display.
Other names: Yingshanhong, Shanshilou, Shanzhizhu, Hongzhizhu
Family: Ericaceae
Morphological characteristics:
Azaleas belong to a diverse genus with various forms. They range from large trees (reaching heights of over 20 meters) to small shrubs (only reaching heights of 10 to 20 centimeters). The main stem can be upright or creeping, and the branches can be opposite or whorled.
There are over 850 species of azaleas, distributed in Europe, Asia, and North America, with Asia having the highest number of species.
Commonly cultivated varieties in China include:
Rhododendron radendum、Rhododendron indicum、Rhododendron simsii、、Rhododendron molle、Rhododendron obtusum、Rhododendron japonicum、Rhododendron fortunei
Key points for cultivation:
Azaleas can be propagated by sowing seeds, cuttings, grafting, and layering.
Peggie was once a high school mathematics teacher, but she set aside her chalkboard and textbooks to follow her lifelong passion for flowers. After years of dedication and learning, she not only established a thriving flower shop but also founded this blog, “Flowers Library”. If you have any questions or wish to learn more about flowers, feel free to contact Peggie.
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