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.
The forests of Papua New Guinea in South East Asia are believed to be the evolutionary homeland of the Bulbophyllum orchids since this is where you can find the largest diversity. Over 600 different Bulbophyllum species have been discovered here. Bulbophyllum orchids can not only be found in South East Asia, they are also naturally occurring in tropical parts of Australia and Africa, and even in South- and Central America. Over 200 species can be found on the island of Borneo alone, and 135 species have been discovered on Madagascar.
It is impossible to provide any Bulbophyllum orchid care guidelines that will be true for every single species in this enormous genus and it is therefore best to look for more detailed information about your specific Bulbophyllum species. Bulbophyllum orchids come in a wide range of forms and shapes. Some are epiphytic and grow on plants, while others are lithophytic and grown on stones and cliffs. Some are root climbers that slowly creep their way up along tree trunks, and yet another group of Bulbophyllum orchids are the tall plants that develop cane-shaped stems. In this genus, you can find orchids that have become almost entirely leafless since their pseudobulbs carry out most of the necessary photosynthesis, as well as orchid species that have adapted to dry conditions and developed succulent foliage. The general characteristics for the genus Bulbophyllum are the basal inflorescence, the mobile lip, and the single-noded pseudobulbs.
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.
If you fail to find species specific information regarding nutrient requirements for your Bulbophyllum orchid, try using a balanced fertilizer (20-20-20) 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.
Most Bulbophyllum orchids are used to tropical environments and need warm to intermediate conditions. Do not let the temperature drop below 55 degrees F (13 degrees C) or rise above 95 degrees F (35 degrees C).
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.
Most species will do well in fine seedling bark mixed with perlite. You can also mount many Bulbophyllum orchid species on a piece of wood or similar. Which potting medium you choose will affect the recommended watering frequency; a mounted Bulbophyllum orchid should be watered more frequently than a potted one.
How and when to repot your Bulbophyllum orchid will greatly depend on the species. Always repot your Bulbophyllum orchid immediately if the potting medium goes bad, e.g. if it becomes infested with mould or starts smelling bad.
Trivia # 1: New species of Bulbophyllum orchids are discovered each year. In 2004, two new Bulbophyllum orchids were described and given the names Bulbophyllum ciluliae and Bulbophyllum orezii.
Trivia # 2: Quite a few Bulbophyllum species emit an odour intended to mimic the smell of a rotting carcass when they blossom. This serves to attract flies which will then carry out pollination for the orchid. These orchid species are naturally not very popular as house plants.