There are numerous species of Dendrobium orchids throughout the world - at least 1,000 are known about and new ones are being discovered all the time. Dendrobium orchids originate from Japan and China and are also found in Malyasia, Borneo, Philippines, New Guinea, Australia and Northern New Zealand. They are epiphytic and grow on trees.
Unlike most other kinds of orchids kept as house plants, some Dendrobium orchids are deciduous and have a period of ‘resting’ during the year, shedding their leaves during our winter; throughout this time, deciduous Dendrobium orchids should be kept cool but in as much light as possible with very little water - a little light misting every week to ten days is sufficient unless they are kept in a dry atmosphere (a winter temperature range of 8 to 12 degrees C is generally ideal, but they cannot withstand frost). Once spring arrives, flower shoots will form on the ‘eyes’ where the leaves fell from, and the plant will begin a rapid growing phase during which time it will require plenty of light, heat and water, and some orchid food. Because these deciduous Dendrobium orchids require rather active ‘management’ they are not the best choice for beginners.
Evergreen Dendrobium orchids are much easier to look after, and they usually grow quite happily with the once-per-week pot-immersion watering regime (see below) that works so well with Phalaeonopsis orchid species.
By far the best way to water evergreen orchids is to place them in a sink or other container of lukewarm water which comes up to the top of their pots. Because they are not growing in densely packed soil or compost, the water will easily rise up from the bottom of the pots and saturate the roots. The plants should be left for several hours, or overnight, and the watering should be repeated on a weekly basis (although most plants will easily survive a 10 interval if you are away). At the same time as watering, spray the leaves with a fine water mist. Feeding should be kept to a minimum and stepped up only once new growth or flower shoots appear. Never overdo it – food is not high on the agenda of survival for plants that live perched up in trees with their roots exposed!
Other kinds of Orchids as House Plants...
Yes, we have many native wild orchids throughout Europe and around 30 species in the UK. Most of them are rare, endangered or in serious decline due to the destruction of their natural habitats. They will not survive being dug up and moved either to gardens and greenhouses or to window ledges. It is also an offence under the Wildlife and Countryside Act to dig up any wild plants without the landowner’s consent.
If you found this information helpful, we are sure you would also like books on the Wild Orchids of Wales, of The Burren, and of the Algarve. Author-signed copies are available here...
There are many local and national nature reserves where wild orchids can be seen at the right time of year, and the network of local Wildlife Trusts can advise you on the best time to visit and also arrange for you to take part in some of the many tours that they organise during peak flowering times.