Editor's Note: This article was originally published on January 9, 2010. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
There is no doubt that Cymbidium orchids are among the most popular orchids to grow as houseplants, cut flowers and even garden plants in mild climates. Few orchids produce as bold a display of flowers. However, there is considerable variation among this genus. There are about 50 species of Cymbidium, all native to SE Asia and neighbouring northern Australia. They may grow epiphytically (on trees), lithophytically (on rocks) or terrestrial. Most of the popular species and hybrids are derived from the terrestrial species. Cymbidium are easily recognized by their relatively large, rounded pseudobulbs and elongate, grass-like leaves.
As most hail from mountainous areas, they tolerate cooler temperatures than many ‘houseplant’ orchids, especially in winter. Indoors, they prefer a sunny location but outside, dappled shade is recommended during the hottest part of the day. Mild areas such as coastal California and Florida can grow these orchids as garden plants as they will survive light frosts. The growing media should be moisture retentive but well-drained. I use a mix of perlite, peat, charcoal or crushed pumice and medium to coarse bark chips works. Some growers even use straight pro-mix with good results as long as care is taken not to over-water. Fertilize regularly during the growing season but withhold in the cooler winter months. Unlike many orchids which require high humidity to thrive, Cymbidium will tolerate normal household humidity levels. Plant size varies considerably. Some like C. goeringii, are often under 30 cm while C. insigne has leaves over 1 metre in length. Often, they are sold as either standards (long, wider leaves, tall spikes with large blossoms) or miniatures (smaller, finer foliage and flowers) but more recently hybrids have been developed which are small-sized plants with wider leaves (but short) and large blooms on short spikes. Flowers vary in colour from pure green to white, pink, red, orange, yellow and even brownish-maroon. Blue is the only colour that does not exist among Cymbidium.
Some species Cymbidium include C. goeringii, C. insigne and C. tracyanum
Cymbidium basically fall into three groups in regards to cultivation. The most popular group are the large-flowered species and hybrids with upright spikes. There are also miniatures among this group which have the species C. pumilium in their ancestry. Plants and flowers look like smaller versions of their large cousins. These require a cooler, drier period in the autumn to initiate spikes which will bloom in late winter through spring. During this period, night temperatures should be kept close to 10 C (50 F). When growing this type, I place them outdoors for the summer after all risk of frost has passed. I keep them under a tree where they get morning sun but dappled afternoon shade. I leave them outside until the weatherman speaks for frost. By that time, the naturally cool autumn nights have often initiated the spikes. I then move them to a sunny, unheated room where I can keep the nights on the cool side.
Examples of modern-day Cymbidium hybrids
The small-flowered species and hybrids from China, Japan (such as C. ensifolium, C. goeringii and C. sinense) do not require a cool treatment are grown under intermediate household temperatures year-round. They may bloom at any time of the year. Some of these are fragrant and several have variegated foliage which adds to their attraction. These are the classical Chinese and Japanese orchids often portrayed in their art. They are often grown in tall, narrow, decorative terra cotta or clay pots.
Examples of Chinese Cymbidium; C. sinense (variegated form and flowers) and C. ensifolium
The last group are the tropical, epiphytic species from the East Indies and northern Australia. These often have thicker, stiffer foliage and pendant spikes of numerous, small, often greenish to brownish flowers. They require warm temperatures all year long and are best grown in hanging baskets to accommodate their cascading flower spikes.
Examples of tropical Cymbidium include C. madidum and C. aloifolium
Hopefully this article will entice you to try some of these wonderful orchids. They are indeed quite alluring and relatively easy to grow as far as orchids are concerned.
I would like to thank the following people for the use of their pictures: boojum (C. tracyanum, C. sinense (variegated form)), huiray (C. insigne), kennedyh (C. madidum) and monocromatico (C. aloifolium).