Updated: Mar 6, 2020
The genus Bulbophyllum is the largest one in the entire orchid family Orchidaceae and currently contains over 1800 orchid species, and new species are constantly being described and added to this vast genus. It is currently one of the largest genera in the entire plant kingdom, only Euphorbia and Senecio contain more species. In the floral trade, Bulbophyllum is abbreviated Bulb.
Bulbophyllum orchid was named refers to the leaf shape. The plants from this genus are native to Australia, South-east Asia, Africa and South America with the greatest diversity found in Papua New Guinea. They are found from the high and low altitude in rain and cloud forests of most tropical and subtropical countries. They have tremendous variation in their growth habit, ranging from fully terrestrial species to giant epiphytic climbers. They can bloom directly from the rhizome or the growth, depending on the species.
General information should only be used as a guide, and should be to be adapted to suit you. Your physical location; where you grow your plants, how much time you have to devote to their care, and many other factors, will need to be taken into account. Only then can you decide on the cultural methods that best suit you and your plants.
It is hard to provide any specific recommendations since Bulbophyllum orchids are found in such a myriad of different environments. If you are unable to find species specific guidelines you can assume that the wider the leaves are, the less light demanding will the plant be.
Bulbophyllum Orchids usually need intermediate light which is less than Cattleyas but more than Phalaenopsis. Higher light, that does not damage the leaves, seems to result in better and more frequent blooming. They can be grown indoors providing they receive good light.
They are regarded as warm to intermediate growers. Most require warm temperatures from 21-27°C but will be comfortable in a temperature range of 7 to 35°C. They will not tolerate frosts. They need a temperature drop of about 6-8°C at night for flowering. Those that originate in high altitude areas of Papua New Guinea prefer lower temperatures and may not be suited to hotter climates. The minimum temperature for the tropical forms is considered to be 10°C and 15°C for equatorial species.
“ Know the Origin of Your Species before setting Temperature”
Also, as mentioned above, it is impossible to provide any guidelines that will be true for all Bulbophyllum species. Many of them are however used to rainy environments and need a lot of water. If you keep one of these species potted, you can water your Bulbophyllum orchid every 3-4 day and allow only a slight drying out between each watering. If you keep the orchids mounted, you can water them twice a day. If a new leaf is smaller than the old one, your Bulbophyllum orchids needs more watering.
Generally, these orchids need to have ample water supply when the plants are in active growth, and a drought of even a couple of days is enough to kill the new growths and set back the plant. Due to their shallow fine root system they need to have constant moisture around their roots, however depending on their origin, some need a distinct wet and dry period to flower. The potting mix should never be allowed to dry out completely. They can be kept slightly drier in winter.
Most species come from humid rainforests. Humidity should be kept at 60% , which can be difficult to do outside of the greenhouse. Water frequently, as both mounted (at least daily) and potted plants (several times a week) will thrive under wetter conditions than most orchids. Bulbophyllum may be the exception to the rule "when in doubt, don't water.
Good air movement is important to reduce the problem of leaf fungal disease due to frequent watering. Where natural humidity is high or where humidification maintains a high degree of humidity, increased air movement is essential to prevent stagnant air and the development of diseases.
They mostly flower in spring, early summer or early autumn but in the right conditions can flower year round. The flowers are small to large and are highly specialized to attract specific insect pollinators and many have a strong pungent odor to attract mainly flies.
If you fail to find species specific information regarding nutrient requirements for your Bulbophyllum orchid, try using a balanced fertilizer two times per month. Divisions should only be given half strength. Seedlings can benefit from a fertilizer high in nitrogen until they are large enough to blossom.
Balanced Fertilizer for Growth: 20-20-20 (NPK) – 1 gram per litre of water – Spray once in every alternative weeks (14 Days)
High-Phosphorus Fertilizer for Blooming: 0-52-34 (MPK) – 1 gram per litre of water – Spray on every alternative weeks (14 Days)
"They are more on the side of Drinking Water than Feeding Nutrients"
Potting , Media and Propagation
Bulbophyllum orchid can be grown mounted on slabs of wood or tree barks. However, all the species can be grown in shallow pots, or even baskets. One requirement is to retain enough moisture at the root, as most species don’t like to dry out. The rhizome can be trained to stay in the pot by bending them, eventually cutting the old bulbs and leaving them in place, so they will provide additional growth in the pot. Sphagnum has been popular because it retains a lot of moisture, which is what these plants prefer when in active growth; however when it decays or starts to retain too many salts, the plants will have problems.
Bulbophyllum species tend to prefer a minimum of repotting. The choice of potting will often be dictated by the very long rhizomes of some species. Re-pot as infrequently as possible. Repotting is best done in spring or autumn when new growth appears at a frequency of about every 3 years.
If dividing a plant, one or two pseudobulbs per division are required. Select a pot that will allow for approximately two years of growth before crowding the pot. Carefully cut the rhizomes with sterile tools and then pot it. After dividing the orchid it is imperative to keep the plants in a humid area while to roots begin to grow.
“Mounting is Preferred on their Mature Stage”
Pests and Other Bulbophyllum Related Problems
Fungal and Bacterial Diseases of Bulbophyllums are common because of the levels of humidity they need to survive. Fungal agents cause problems like root rot, leaf spots, leaf blights and distortion in flowers.