Habitat and Ecology
Dendrobium unicum, commonly known as the Unique Dendrobium, is a beautiful, miniature epiphytic or lithophytic orchid native to Indochina, with a distribution including Northern Thailand, Laos, and Vietnam. It is found in evergreen, semi-deciduous, and dry lowland forests and savannas at altitudes typically between 800 and 1,550 metres. Its native habitat is characterised by a distinct seasonal pattern of hot, wet summers (active growth) and a cool, relatively dry winter rest period, which is critical for flower initiation.
Description
This is a miniature-sized, deciduous or semi-evergreen orchid that forms tight, clustered growths of small, thin, cane-like stems (7-9 cm long). Each stem typically carries two to three narrow, persistent leaves at the apex during the growing season. The plant's distinctive feature is its flower: relatively large (3.5-5.0 cm wide) and borne on short spikes that emerge from the upper nodes of the leafless or semi-leafless canes in late winter to early summer. The blooms are a striking, unusual, and intense colour, usually deep orange or bright red-orange. The petals are long and slender, sometimes twisted, and the prominent lip is cupped and often creamy-yellow with fine reddish-brown veins and three central ridges. The flowers are fragrant, often described as having a sweet, fruity scent reminiscent of mandarins.
Cultivation
Dendrobium unicum is a cool-to-warm growing orchid that requires a strong seasonal shift to flower well in the UK. It needs bright, high, filtered light; it can tolerate some direct sun outside of the summer peak, but should be protected from scorching midday sun. It is often best mounted on cork bark or wood to ensure rapid drying, though it can be potted in a coarse, fast-draining orchid bark mix. A strict cool and dry winter rest period is mandatory for blooming.
Optimal Daytime Temperature (Growing Season - Spring/Summer): 25-30 C (77-86 F)
Optimal Nighttime Temperature (Winter Rest - Late Autumn/Winter): A minimum of 10-12 (50-54 F) is needed to set buds.
Water should be severely reduced during this rest. Provide high humidity (70-85%) during the growing season, combined with strong air circulation. Water daily when mounted during summer, but only sparingly in winter, just enough to prevent the canes from shrivelling excessively.
Unique Features
As its name suggests, the Unique Dendrobium is prized for its unusual, vivid orange-red colouration (rare in the genus) and the strong, sweet, tangerine-like fragrance of its flowers. Its miniature size makes it highly manageable, and its reliable winter-to-spring bloom from the leafless canes provides a dramatic burst of colour when most other plants are dormant. Successfully providing the necessary cool, dry winter rest is the key to unlocking its unique and abundant floral display.
Specifications
Plant Size: Plants from flask two years ago. 1-2 years from flowering.
Plant Family: Orchidaceae
Plant Passport: A Dendrobium unicum B 140084 C [user input] D GB
