Name: Cymbidium sinense
Cymbidium sinense is an orchid native to South-Eastern Asia, and it can for instance be found growing in India, Burma, Thailand, and China. It normally reaches a height of 25-60 cm. It has a long tradition as a potted plant in China.
Flowers The scape is 40-80 cm and this orchid develops 6-26 flowers, which are roughly 5 cm across. The flowers have a very strong scent. The Cymbidium sinense orchid blossoms in the New Year period and is therefore known as hosairan – “orchid that tells the New Year” – in Japanese.
Light Cymbidium sinense is growing in Asian forests where it gets shade or semi-shade from the trees. Roughly 40% shade is recommended during early spring and late fall, 60-70% shade in mid spring and early fall, and 80-90% shade during the summer months. (These figures naturally have to be adjusted depending on your geographical location.) Gradually remove the shade during winter.
Providing your Cymbidium sinense orchid with proper temperature is very important if you want to ensure optimal blooming. The recommended summer temperature is 75-80% degrees F, but higher temperatures can be acceptable if you provide plenty of air movement. In order to promote the formation of flower spikes, the night temperature should be decreased down to 50-60 degrees F during late summer and early fall (August to October in the northern hemisphere). The recommended winter temperatures are 65-75 degrees F during the day, and 45-55 degrees F during the night.
Watering and humidity
Cymbidium sinense is a terrestial species and its roots should always be kept moist. (There is however a big difference between moist and wet/soggy.) You have to adjust the watering depending on medium, temperature and air humidity. Under normal indoor conditions, 1-3 waterings per week is standard. Do not water your Cymbidium sinense orchid during the hottest hours of the day during the summer season.
The recommended humidity is 50-50% during the winter season. During the summer season, the humidity should be even higher.
Potting medium Cymbidium sinense is a terrestrial orchid and should therefore not be mounted. It is known to grow well in tall and narrow pots. The roots are very long and a tall pot is therefore better than a shallow one. Make sure that the potting medium dries out evenly, and punch holes on the sides of the pot if necessary. In Asia, this orchid is normally grown in pots where large rocks are placed at the bottom, medium sized rocks in the middle, and small porous stones at the top. If you fail to find rocks, you can instead use coarse bark in the bottom and finer bark at the top.
Repotting When you repot your Cymbidium sinense, use a container that is big enough for the orchid to grow for 2-3 years without having to be repotted. The best time of year for repotting is spring, right after the flowering. Gently remove all the old potting medium from the roots without harming the roots. Place the rhizome ½ inch below the surface of the new potting medium. Never compact the mix after repotting. A newly repotted plant should be kept in the shade until new growth starts, and you should only give it very small amounts of water.
Propagation It is possible to divide Cymbidium sinense; just maintain 2-3 bulbs with leaves in each division when you repot.