Renanthera citrina from Vietnam

RHS

Houseplants Conservatory Greenhouse

An epiphytic orchid with woody stems to 20cm long carrying leathery, lanceolate leaves. Up to 25 flowers are borne on stems to around 45cm long from winter into spring; flowers to 6cm long are pale yellow with 1-3 purple spots on the petals and 3-lobed lips

Position

Partial shade

Soil Types

Loam

Max Height

0.1-0.5 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 2–5 years
Max Spread: 0.1-0.5 metres
Max Height: 0.1-0.5 metres

Growing Conditions

Loam

Moisture: Well–drained
pH: Acid or Neutral

Position

Partial shade

Aspect: North–facing or West–facing or East–facing
Exposure: Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

H1A: under glass all year (>15C)
H1B: can be grown outside in the summer (10 - 15)
H1C: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20): H1C

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Orchidaceae
Native to GB/Ireland: No
Foliage: Semi evergreen
Habit: Columnar upright
Genus: Renanthera is a genus of large, scrambling epiphytic and terrestrial orchids native to China and the Himalayas. Orchids within this genus produce branched stems with an abundance of flowers in shades of yellow, orange of red.
Name Status: Unresolved

How to Grow

Cultivation

Grow in epiphytic orchid compost and from late spring to summer, in partial shade with good ventilation, day temperatures between 18-25°C and night above 10°C, water freely adding orchid fertiliser every third watering and provide high humidity by misting twice daily. Keep in well lit conditions from autumn to early spring and keep dry in winter. See indoor orchid cultivation

Propagation

Propagate by division when the plant over-fills the pot

Suggested planting locations and garden types

Patio and container plants

Pruning

No pruning required, cut down flowered stems as necessary

Pests

May be susceptible to aphids, glasshouse red spider mite and mealybugs

Diseases

Generally disease-free