Hard cane dendrobiums are hybrids of the Dendrobium species of Sections Phalaenanthe and Ceratobium and involve in their parentage, species that are found growing in the hot, equatorial and tropical forests of Asia. They are the easiest plants to grow for a beginner and bloom profusely without much care. For this reason, they are very popular in the tropics. Of late, small teacup varieties have been bred with blooms on plants as small as 2 inches. They commonly come in pink, white, brown, purple, yellow, green and maroon shades.
Light: Dendrobiums can tolerate a lot of light provided they are introduced to it gradually. In the tropics where strong light is associated with heat, plants that are kept in the open can suffer burns when the sun comes out after the monsoons. Ideally, dendrobiums do well under nets allowing 50-60% sunlight to pass through. Plants receiving lesser amounts of light have leaves that are dark green and flowering will be markedly reduced. Ensure that your plants are protected from the afternoon sun especially during the summer. For those who do not have greenhouses, east or west facing balcony which receives a few hours of sunlight would be ideal.
Water: Dendrobiums are sympodial orchids with pseudobulbs that can store food and water. In monsoon-fed regions especially along the West Coast where humidity is high, watering can be done just once during the hottest part of the day and it goes without saying that they need not be watered during the monsoons. Water only if you notice the media and roots on the surface to be dry. More dendrobiums are killed due to overwatering than underwatering. A dendrobium cane(pseudobulb) that looks shriveled indicates it is not getting enough water. Such plants should be watered more often.
Humidity: Hard-cane dendrobiums are not very particular of humidity though they will grow best where humidity levels are between 50-80% throughout the year. Where humidity levels are quite high, no additional setup is necessary. Hobbyists in other regions will either need to setup misting in their greenhouses or place humidity trays beneath their orchids after ensuring that water from the trays does not enter the pots. •
Temperature: Being tropical in nature, they best enjoy temperatures between 20 C -30 C. Unlike the soft cane dendrobiums that require a distinctly cool and dry season to bloom, these will bloom happily throughout the year irrespective of a temperature differential between day and night. They can be grown over most of India but might need to be protected from the cold winds in the North-East during winter. In the North-East, watering should also be markedly reduced during this period as the plants enter dormancy.
Media and Fertilizer: As mentioned earlier, dendrobiums being very forgiving can be grown in a wide variety of media. Ideally, use water-retaining media like LECA pebbles along with charcoal about a half inch to an inch in diameter. In monsoon-fed regions, coconut husk should be avoided although if necessary large pieces can be used. In drier climates, coconut husk can be used liberally. When selecting pots, choose a pot that has a residual space of 2 inches from the base of the plant to the rim of the pot. Dendrobiums are known to bloom faster once they become pot bound. Repot once the pseudobulbs begin to grow out of the pots or once every 2 to 3 years. They should be preferably grown in raised benches to prevent soil-borne infections. Benching also ensures optimal light levels reach the plant and also increases air circulation around the plant. They can be fertilized once a week using a bloom fertilizer with a high potassium ratio along with micronutrients at the recommended concentration. Spray the leaves and also the roots until fertilizer runs out of the pot.