Dendrobium farmeri - Farmer's Dendrobium

This is an Asian epiphyte that grows in humid tropical as well as sub-tropical regions of Asia. In its natural home, this orchid is generally seen growing on the main trunk of tall trees far away from the ground. Though, near water bodies, you may also find this orchid growing on the various branches too.

Taxonomic details (scientific names and local names): Earlier, Dendrobium farmeri was also called Callista farmeri and Dendrobium farmerii. Common names of Dendrobium farmeri are farmer’s dendrobium and sentinel orchid.

Physical description: Unique feature of this orchid is its four angled canes, which has leaves growing out near the tip of the canes. Flowering shoots grow on previous seasons’ canes after shedding their leaves. 

Flower details: Beautiful and sometimes scented flowers of Dendrobium farmeri mostly white with a big yellow patch on the lip; however there are different local varieties in which white colour may vary from pink to violet. This orchid starts blooming when temperatures begin to rise.

Cultivation:
1. Light: Dendrobium farmeri requires direct sunlight for a short period of time at least once during the day, be it early in the morning or late in the evening when the sunlight is not very strong. Rest of the time partial sunlight should be provided. Please note that this orchid will not flower if kept in shade.
2. Watering: Under natural condition, it often gets soaked in the summer rain, however, winters are normally dry. Therefore, frequent watering is required during the active growing season that is in summers when the orchid is blooming. The watering regimen should be restricted to spraying the canes with water in winters. This is necessary to prevent canes from ‘dying from drying’. 
3. Air circulation: It grows on the trunk of the host tree, where the air circulation is quite unrestricted. So, there should be plenty of free circulation of air for healthy growing Dendrobium farmeri.
4. Growth medium: The best way to grow is to mount it on a piece of wood, using coconut fibres as a growth medium or better still you can fix it to a tree branch, then it would not require repotting. If potting it in a container, care should be taken that the growth medium dries out in between watering and is very slow to decay. The commercially available ‘orchid mix’ can also be used as the growth medium. 
5. It can grow in isolation as well as with other epiphytes (ferns or other orchids). So it can be grown on the ‘orchid tree’. Dendrobium farmeri propagates through seeds or by separating the canes from the base such that each separated portion has some roots attached. Kiekies are also formed, which should be removed only when the roots appear near the base of the new growth. 
6. Fertilization: It does not require much fertilization. However, to be on the safer side we can go for a ‘weekly weakly’ fertilizer application, mostly when the orchid is in the flowering stage. According to some growers, most kind of fertilizer combination seems to work for Dendrobium farmeri. 

Pest and Diseases
This orchid is highly susceptible to rot. So if right conditions are not provided, the plant can die very quickly. Dendrobium farmeri does not like repotting, so use a growth medium that is slow to decay. 
This orchid gets infected with common pests and diseases of orchids. Pests such as thrips often attack the orchid when it is in flower and these have become resistant to many pesticides. The best remedy is preventing the pests and diseases to take hold of your orchid. However, in the case of infection, it is best to remove the infected plant and to prevent the spread of infection.