Please note:  There are hundreds of species of Dendrobium and the preferred environmental conditions vary between them.  These culture notes are applicable to Dendrobium as supplied by Ivens Orchids.

Dendrobium (den-DROH-bee-um) hybrids are descended from species originating mainly in eastern Asia and Australia.  The majority of Dendrobiums available from Ivens Orchids are Phalaenopsis type hybrids that require similar growing conditions to Phalaenopsis.

The second type of Dendrobium grown at Ivens Orchids is Dendrobium kingianum; these require cooler growing conditions.

1. Dendrobium Phalaenopsis

Sometimes known as Singapore orchids, these beautiful plants are easy to keep in normal home conditions.  They have lots of strong coloured blooms ranging from pure white through pale to vibrant pink, purple to black and lemon to bright green.  They will happily grow alongside Phalaenopsis although they may need a little more light to get them to flower well.  The flowers are held on sprays that shoot from the side or top of fleshy stems, known as canes, that are actually elongated pseudo-bulbs and are used as storage organs for the plant. 

Temperature:  Phalaenopsis type Dendrobium prefer higher temperatures of 18-28^oC .

Light:  Dendrobium like plenty of bright filtered sunlight but avoid direct sunlight that may scorch the leaves. They can be difficult to re-flower if they do not receive sufficient light.

Water:  Once a week throughout the year.  Water from the top and allow any excess to drain away.  Clean rainwater is preferred by the plant but you can use filtered tap water.

Note:  NEVER STAND THE PLANT IN WATER.  This will cause the roots to rot and kill the plant.

Feed:  Once a week using a balanced orchid fertilizer such as Ivens Orchids’ Orchid Feed.

Air Humidity:  Moist air is essential.  The humidity can be raised by placing the plant on a tray of moist gravel or pebbles, and spraying a mist of water above the plant once a day will help.  60-70% humidity is ideal.

2. Dendrobium kingianum

Dendrobium kingianum have tapering pseudo-bulbs 15-30cm high with 10cm long leaves crowded near the top of each.  They flower in the spring and very often have a strong hyacinth-type scent to the flowers.  The flowers are about 1-2cm across and colours are pure white and pink to purple.

Temperature:  Dendrodium kingianum prefer intermediate temperatures of 13-16^oC at night and 18-24^oC during the day.  To initiate flowers, the nighttime temperature should be dropped to 13^oC during winter months.

Light:  Dendrobium like plenty of bright filtered sunlight but avoid direct sunlight that may burn the leaves. They can be difficult to re-flower if they do not receive sufficient light.

Water:  Once a week throughout the year, water from the top and allow any excess to drain away.  Clean rainwater is preferred by the plant but you can use filtered tap water if necessary.

Note:  NEVER STAND THE PLANT IN WATER.  This will cause the roots to rot and kill the plant.

Feed:  Once every other week using a balanced orchid fertilizer, such as Ivens Orchids’ Orchid Feed.

Air Humidity:  Moist air is essential.  The humidity can be raised by placing the plant on a tray of moist gravel or pebbles and spraying a mist of water above the plant once a day will help, but is not essential.  50% humidity is ideal.

General Dendrobium Culture Information

After Flowering:  Dendrobium will flower for 6 to 10 weeks.  Cut off old flowers near the base of the stem but do not cut the cane.

Repotting:  Compost seldom remains in good condition for more than two years and, like most other orchids, the plant will benefit from occasional repotting.  This is best done just as the new roots and shoots are developing.  Older plants can be divided by splitting large clumps into 4 or 5 canes.  Make sure the new plants have at least three old canes with the new ones, as the flowers will develop on last season’s growth and the old cane will store energy for the plant.  Use a clear pot and good quality orchid compost such as Ivens Orchids’ General Purpose Compost.

Basic Repotting Technique:  Tap the plant out of its old pot and inspect the condition of the root-ball.  Shake off any decaying compost and remove all the dead, soft or black roots.  Remove any old black or soft canes with no roots but be sure to leave the old canes if they are sound and healthy.  These will help to support the plant should it become stressed after repotting.  Using a pot big enough to take a year’s new growth, support the plant in the centre of the pot while you feed fresh orchid compost around the root-ball.  Do not pack the compost in too firmly as these plants prefer a free draining pot.  Always dampen down the compost before potting and only water sparingly for the first 4 to 6 weeks after repotting allowing the plant to get used to the new conditions.  

Pests:  Prevention is always better than cure so look for good healthy plants to start with and keep them that way with a clean environment for your plants.  Throw away old, weak or infested houseplants and maintain good housekeeping in the greenhouse.  Most often seen pests are scale insect, aphids, mealy bug and red spider mite.  All of these will weaken the plant if left unchecked.  The scale and aphids may be cleaned off with soapy water, if found early enough, otherwise treat with a specific systemic insecticide.

Buying Tips:  Always buy good quality orchids from a reputable supplier and look for clean healthy plants.  The leaves are a good indication of a plants health; they should be pert and of good colour.  Unless you have ideal transportation and growing conditions, buying a plant with immature buds may be a mistake as some plants can be sensitive to being moved during the early stages of flower development.  Look for plants whose flower buds look quite plump and ready to open. 

Handy Hint:  Keep your plants clean and healthy by occasionally cleaning the leaves with a mixture of 1 tablespoon of olive oil and a few drops of washing up liquid mixed in warm water.  Using a sponge cloth, wipe over the leaves with the mixture. 

Note:  To help prevent flower and bud drop, keep plants away from drafts, radiators and other heat sources.