Growing Bulbophyllum indoors and in greenhouses
Unusual, diverse and often wonderfully eccentric, Bulbophyllum is one of the largest and most fascinating orchid genera. Its flowers range from delicate and intricate to bizarre and dramatic, often accompanied by distinctive fragrances – occasionally sweet but more often unpleasant, designed to attract flies rather than humans. Despite a reputation for unruliness, many commonly grown Bulbophyllum are surprisingly manageable, provided their need for moisture, humidity and airflow is understood.
OVERVIEW
The genus comprises over 2,000 recognised species (Source: Kew), distributed across tropical regions of Africa, Asia, Australasia and the Americas. They are particularly diverse in Southeast Asia and New Guinea.
Most species are epiphytic, though some are lithophytic. They typically grow in warm, humid forests where airflow is constant and moisture is abundant.
Bulbophyllum are sympodial orchids, characterised by:
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Short, creeping or lengthy, rambling rhizomes
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Defined pseudobulbs bearing one or two leaves
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Inflorescences arising from the base of the pseudobulb
Growth habit varies enormously – from compact miniatures to sprawling specimens – making it important to understand the specific type being grown.
Bulbophyllum smitinandii
Bulbophyllum guttulatum
Bulbophyllum frostii
CARE ESSENTIALS
■ Light
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Bright, diffuse light is ideal, similar to Phalaenopsis or slightly brighter.
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Avoid strong direct sun, especially through glass.
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Leaf colour guide: mid-green = ideal; dark green = too little light; yellowing or reddening = too much light.
Exceptions:
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Some species (e.g. Bulbophyllum medusae) tolerate brighter conditions.
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Miniature cloud forest species prefer lower light.
■ Temperature
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Most commonly grown species prefer intermediate to warm conditions.
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Ideal daytime range: 20–28°C; night-time: 14–20°C.
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Avoid cold conditions and sudden drops in temperature.
Exceptions:
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Highland species (e.g. from New Guinea) prefer cooler conditions.
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Lowland tropical species require consistently warm temperatures year-round.
■ Watering and humidity
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Bulbophyllum generally do not tolerate drying out so should be kept evenly moist at all times.
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Water thoroughly and frequently and never allow plants to become bone dry.
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Ideal humidity: 60–80%.
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Good airflow is essential to offset high humidity and minimise stagnant conditions around the roots.
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Rainwater, reverse osmosis or low-mineral water is preferable, and flush regularly if using tap water.
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Thin roots and rhizomes dry quickly – prolonged dryness leads to rapid decline.
Exceptions:
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Some species with thicker pseudobulbs tolerate slight drying between watering.
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Mounted plants dry faster and require more frequent watering and high humidity.
■ Fertilising
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Feed lightly but regularly (“weakly, weekly”) during active growth with a balanced fertiliser.
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Increase feeding slightly during periods of rapid growth.
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Flush regularly to prevent salt build-up.
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Mounted plants may require more frequent feeding at lower strength to compensate for an increased watering regime.
■ Potting and repotting
Potting media:
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Fine to medium bark, sometimes mixed with sphagnum moss or perlite.
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Some growers use sphagnum-dominant mixes for moisture retention, but bear in mind that not all bulbophyllums grow naturally with mosses.
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Reasonably shallow pots or pans are most suitable.
Mounting:
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Many species do exceptionally well mounted, and it’s important to choose a mount that is both long-lasting and one that will accommodate the plant’s future growth to avoid frequent disturbance.
Repotting:
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Bulbophyllum grow mostly horizontally – plan ahead for spread rather than height. Allow space for creeping growth.
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Best done when new roots begin to grow.
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Do not bury the rhizome – keep it on the surface of the potting mix.
GROWTH HABIT AND VARIATION
Understanding your plant’s growth style is essential to long-term success.
Standard form:
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Widely spaced pseudobulbs along a rhizome.
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One or two leaves per pseudobulb.
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Flowers are produced from the base of a pseudobulb.
Variations:
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Clumping types – more compact and easier to grow in pots.
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Long, rambling rhizomes – quickly outgrow containers.
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Miniatures – ideal for terrariums or controlled environments.
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Large species – require significant space and humidity.
COMMON MISTAKES
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Allowing plants to dry out is one of the fastest ways to lose roots and set them back.
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Insufficient humidity leads to poor growth and shrivelled pseudobulbs.
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Poor air movement encourages rot in humid conditions.
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Overpotting or burying rhizomes leads to rot and plants that don’t establish well.
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Too much light causes leaf stress and reduced vigour.
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Ignoring the differences between species and treating all Bulbophyllum the same is a common cause of failure.
SUMMARY
Bulbophyllum bring character and curiosity to any orchid collection, offering an extraordinary range of form, flower and fragrance. While their care requirements vary, most share a preference for consistent moisture, good humidity, moderate shade and excellent airflow. Once these fundamentals are understood – and the differences between species respected – many Bulbophyllum prove to be rewarding and surprisingly accommodating plants.