About
A medium-sized, epiphytic orchid with upright, 15-30cm long, evergreen leaves. Each flower measures 5-10cm across. Each stem carries 8 to 20 white, star-shaped flowers, often with dark burgundy red spots and toothed edges. New flowering stems arise from the axils of young, mature pseudobulbs and the leafed sheaths. The plant typically flowers in winter, spring or autumn on up to 45cm long, upright or arching stems. They are egg-shaped, slightly flattened and partially covered by one or two pairs of green, leafed sheaths. Each pseudobulb is a storage organ for water and nutrients. New growth appears from the base of the swollen stem - pseudobulb.
About the genus
Oncidium are a large genus of epiphytic orchids; mature plants form clumps of ovoid to conical pseudobulbs, each with 1-3 mid-green, variably-shaped, leathery leaves arising from the tips. Flower panicles from the bases of the pseudobulbs widely differ in colour and shape
Growing conditions
SunlightPartial shade
Soil pHNeutral
Soil moistureMoist but well-drained, Well-drained
AspectEast-facing, North-facing, West-facing
ExposureSheltered
UK hardinessH1B
Plant details
Plant typeConservatory Greenhouse
HabitColumnar upright, Clump forming
FoliageEvergreen
Height0.5-1 metres
Spread0.1-0.5 metres
Time to full height5-10 years
Suggested usesHouseplants
Native toBrazil
ToxicitySkin allergen. Wear gloves and other protective equipment when handling
Care notes
CultivationGrow in an open bark-based orchid compost with addition of perlite, sphagnum moss or coir. Provide enough bright filtered light, but keep away from direct sunlight or a heating source. Ideal temperatures are around minimum 8°C at night and up to maximum 25 °C during day. Water regularly, when the pot feels light when lifted. Ensure that all water drains away, preventing the plant sitting wet. Orchid fertiliser can be applied regularly throughout the growing season. Reduce watering and feeding in winter months. For more notes on cultivation, see oncidium orchid (cool) cultivation
PruningNo pruning required. Cut off spent flower spikes.
PropagationPropagation by seed is only possible in a controlled laboratory environment. Mature plants may be divided when the plant overgrows its container. Each division should have at least 3 older pseudobulbs with a sufficient amount of stored energy and water, to support new growth and reduce stress after repotting.
Pest resistanceMay be susceptible to mealybugs, aphids and scale insects.
Disease resistanceGenerally disease-free. Poor air movement may cause bacterial or fungal rots. Good hygiene practice and sterilising cutting tools prevent the spread of virus diseases.