RHS Garden Wisley

Cymbidium Orchids Family: Orchidaceae Vital statistics Height and spread: Up to 90cm (3ft) Form: Mainly epiphytic Soil: Very free draining orchid compost Aspect: Dappled shade to full sun Hardiness: Requires heated glass

Cymbidiums and other orchids can be seen in flower year round in the Singapore Airlines Orchid Display House. Although the more spectacular species are in flower during winter and spring, many interesting and decorative forms can be seen at other times.
For two weeks during January the annual 'Orchids for All' exhibition takes place, with various lecture, demonstrations and guided tours of the collection.

Cymbidium

Originating in temperate and tropical parts of India, Nepal, China, Japan and down to Malaysia and Australia, cymbidiums are probably the most widely grown of all orchids because of their ease of cultivation and long-lasting flowers. From the 40-50 species, thousands of hybrids have been bred, with flowers ranging in colour from white, yellow and orange to pink, red, brown and green, and varying in size from 5-10cm (2-4in) across.
Cymbidiums figure in the earliest historical records of human association with orchids from China and Japan. These include Chinese folk songs composed before the time of Confucius (551-479 BC).
The first written work on orchids was published in China in 1233AD and listed 22 orchids with descriptions. The first systematic description and classification of the genus occurred when Olaf Swartz established it formally in 1799.
The first cymbidium was introduced into England by James Fothergill from China in 1778 and the first cymbidium hybrid was bred in 1889.
The name Cymbidium comes from the Greek word kymbe meaning boat, from the hollow recess in the lip of the flower.

Cymbidium hybrids

Incredibly no more than seven or eight species have been responsible for 90 per cent of the thousands of Cymbidium hybrids we have today. During the 1930's and 40's many popular hybrids were bred in America, though by 1960 there was a transition to a dominance of British-bred hybrids.
Cymbidium hybrids can be split into three groups, standard hybrids, miniature hybrids and novelty hybrids, which are sometimes called intermediate hybrids.
Standard hybrids grow into large plants and take up a great deal of space. Most flower in late winter and spring for up to two months and are available in almost every colour except blue.
Miniature hybrids have been bred from dwarf species such as C. devonianum and C. tigrinum. While the colour range is limited to green, yellow or brownish flowers, some are pleasantly scented.
Novelty hybrids result from crosses between miniature and standard hybrids and are some of the best modern hybrids available.
The leaves of standard cymbidiums are strap-like, upright or pendulous and 50cm (20in) or more in length, with those of miniature plants being much narrower and shorter
With careful selection it is possible to have a collection of cymbidiums flowering all year around. Flowers are borne on sturdy stems well clear of the foliage many will last up to two months either on the plant or as a cut flower.

The Award of Garden Merit is not given to tender hybrid orchids, due to their often very limited period of availability.

Cultivation

Cymbidiums require a heated environment during the winter, though they can benefit from being placed outside during the summer. To initiate flowering many hybrids require a drop in night temperature and they will also not flower if they do not get sufficient light.
Cymbidiums must be potted with the base of the pseudobulb at or just above the level of a very free-draining potting mix in a well drained container. Cymbidiums are quite vigorous and may need dividing and repotting every two or three years into 20cm (8in) containers.
The level of watering is determined by the time of year. During the summer plants may need watering daily but during the winter this could reduce to once every two weeks. The compost mix should be kept moist and enough water given at each watering for water to pour through the mix.
Cymbidiums are prone to many of the common glasshouse pests, including red spider mites, aphids, whiteflies and mealybugs. Virus diseases can also be a problem which can be avoided by disinfecting tools and equipment to stop it spreading.

Propagation

In addition to regular division new plants can be grown from the older, leafless bulbs. These 'backbulbs' may look dead but they will regrow if they are detached from the younger plants. Plant the bulbs into small individual pots filled with a coir compost and bark mix and keep damp. Once good leaf and root growth are evident they can be potted into a normal orchid compost. Backbulbs will generally flower after three years.

More information

More information on growing orchids, including Cymbidium and Phalaenopsis can be found by clicking here.

The RHS publishes The Orchid Review, the oldest and most respected orchid publication in the world. It contains essential information for breeders and hybridists all over the world and includes the most recent RHS award-winning cultivars in colour, in-depth studies of particular genera, reports on expeditions around the world and information on plants in their habitats.