Rosebay
Rhododendron aureum

Family: Ericaceae

What it is like

Rhododendron aureum is an evergreen Shrub growing to 0.5 m (1ft 8in) by 1 m (3ft 3in). See above for USDA hardiness. It is hardy to UK zone 2. It is in leaf all year, in flower in May, and the seeds ripen from July to August. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid soils and can grow in very acid soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 0.5

Where it is found

Thickets in high mountain areas, both alpine and sub-alpine. Grasslands or liverwort-mosses strata in the alpine region at elevations of 1000 - 2500 metres.

E. Asia - China, Japan, Korea.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 0

Medicine

Rating: 2

The flowers are used in Tibetan medicine, they are said to have a bitter taste and a neutral potency. Caution should be exercised when using the flowers because they are toxic. Haemostatic, they are used in the treatment of spreading pus and blood in the thoracic region, especially the lungs.

Antirheumatic: Treats rheumatism.

Diaphoretic: Induces perspiration.

Haemostatic: Controls internal bleeding.

Homeopathy: A plant used in homeopathic treatments.

VD: Used in the treatment of venereal disease

Other

Rating:

How it is grown

Succeeds in a most humus-rich lime-free soils except those of a dry arid nature or those that are heavy or clayey. Prefers a peaty or well-drained sandy loam. Succeeds in sun or shade, the warmer the climate the more shade a plant requires. A pH between 4.5 and 5.5 is ideal. Succeeds in a woodland though, because of its surface-rooting habit, it does not compete well with surface-rooting trees. Plants need to be kept well weeded, they dislike other plants growing over or into their root system, in particular they grow badly with ground cover plants, herbaceous plants and heathers. Plants form a root ball and are very tolerant of being transplanted, even when quite large, so long as the root ball is kept intact. Closely related to R. caucasicum. This species is very rare and difficult to cultivate. Plants in this genus are notably susceptible to honey fungus.

Propagating it: Seed - best sown in a greenhouse as soon as it is ripe in the autumn and given artificial light. Alternatively sow the seed in a lightly shaded part of the warm greenhouse in late winter or in a cold greenhouse in April. Surface-sow the seed and do not allow the compost to become dry. Pot up the seedlings when they are large enough to handle and grow on in a greenhouse for at least the first winter. Layering in late July. Takes 15 - 24 months. Cuttings of half-ripe wood, August in a frame. Difficult.

Best place to grow: Woodland Garden Dappled Shade; Shady Edge;

Habit: Shrub

Hardiness:

Growth:

Soil: Light (sandy), medium

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Although no specific mention of toxicity has been seen for this species, it belongs to a genus where many members have poisonous leaves. The pollen of many if not all species of rhododendrons is also probably toxic, being said to cause intoxication when eaten in large quantities.

Its other names

Local names

Synonyms

R. chrysanthum. Pall.