This is an evergreen shrub, with an open form, growing to about 2M tall. The leaves resemble normal rhododendron leaves in their leathery feel, but have no intumescence on their underside. Vireyas require acid soil.
Vireys are the largest Section of Rhododendrons, comprising some 300 species. All originate in South-East Asia, from Thailand to Australia. R. “Tropic glow” is a cross between the species R. laetum and R. zoelleri, made by Tom Lelliott in Australia (date unknown) and registered by Os Blumhardt in 1984. R. laetum is a rhododendron species native to the Anggi Lakes area of the Arfak Mountains in Indonesia and western New Guinea, where it grows at forest edges, in open marsh, and at the edge of lakes. R. zoelleri is widely distributed throughout New Guinea and extends to the Moluccas. It is terrestrial in low forests, hanging over cliffs and riverbanks and in high forests goes up into the trees as an epiphyte.
Soil / Aspect:
Vireyas prefer partial or dappled shade in well-drained soil. Rather frustratingly they require sunshine to flower well. How to achieve this without the soil drying out in summer is a problem. In my garden our Vireya is planted just south of a low Euonymous hedge, so the base of the plant is in almost permanent shade. Vireyas are not fully hardy, though they seem to be untroubled by the light frosts we get in Karin’s Garden.
It is important that young plants are kept well watered during summer. Prune after flowering to maintain the shape and promote new growth, though on young plants this only amounts to gently snapping off the spent flower heads. Older, established plants will tolerate moderately hard pruning. Generally pest and disease free, though they may require spraying to control thrip in Karin’s Garden.