GROWING CYMBIDIUMS
Cymbidiums make wonderful outdoor pot plants, easy to grow, tolerant, relatively fool-proof and exceptionally generous. They usually flower once a year, at the same time each year, the flowers lasting for many weeks. During the flowering period, they may be kept indoors, to enjoy the flowers at close quarters. The parent species of Cymbidiums are plants which live on trees and rocks in the foothills of the Himalayas and the highlands of South East Asia, As with all other plants, they require light, air, water, food, a support medium and occasionally some pest control. 
Light: In the wild, Cymbidiums live up trees to get close to light and are not denizens of shady jungles. However, full mid-day summer sun is likely to bum their leaves. Grow them either under 50% shade cloth, or under a deciduous tree where they can receive full sun until mid-morning, dappled shade for the heat of the day and a little late-afternoon full sun.
Air; Air movement promotes healthy plants. Gale-force winds are likely to be very drying and may cause mechanical injury to plants. Although a maximum temperature of 30°C is desirable, short periods of up to 35 to 40°C are not particularly deleterious. Minimum temperatures down to minus 1°C will cause no damage. Below this temperature flower damage will occur and below minus 5°C plant damage will become apparent. For flowering to take place, night temperatures should be about 10°C below day temperatures during the flower initiation period in November and December.
Water: A humid atmosphere is desirable and can be promoted by wetting down the surrounds daily. Watering should be thorough, as needed; the potting medium should not be allowed to dry out completely. As a rule, if the plant is going to be dry tomorrow, water it today? Watering intervals will range from every second day in mid-summer to once per week in winter, depending on rainfall.
Food: Cymbidiums are not gross feeders, but do respond well to light fertilization, particularly in the cooler months. Use a soluble fertilizer such as Multifeed-P at half the manufacturer's recommended strength once per week or fortnight, or a slow release fertilizer such as Osmocote or Multicote 5:1:3 as a single dose annually in April.
Support Medium: Plants are usually potted in free-draining, pine bark mixes, which are available from general nurseries. Do not use garden soil. Dividing and repotting is best done between October and December.
Pests: Slugs and snails are the worst enemies of Cymbidiums. Regular use of a bait such as Mesurol (a small quantity around the plants every two weeks in the flowering season) gives good control. Scale insects can be treated with Chlorpyrifos spray twice, at an interval of two to three weeks. In the case of rot the plant should be unpotted, cleaned and all the diseased tissue cut out. The wounds should be dusted with sulphur and the plant repotted in new potting mix.
©2003 Greig Russell
Greig Russell, "Valhalla", Osborne Lane, Kommetjie, Western Cape.    (021) 783-3962
e-mail: grussell@absamail.co.za      Website: http://www.geocities.com/pennypoint9/