Cymbidium orchids are recognizable by their firm waxy flowers and the large scale of the plants and blooms. They flower once a year in a wide range of hues from crisp white and pale green to deep dusty claret. They are a species of epiphytic orchid that grow in soil-less conditions and thrive in both indoor and outdoor settings with ample sunlight.
Cymbidiums require a cool to temperate growth environment with ideal ambient temperatures hovering between 45 and 70 degrees Fahrenheit, depending somewhat on the specific varietal. The cooler temperatures at the lower end of the range are needed in the late summer and fall each year to set the bloom cycle in motion.
Feed your cymbidium orchid once a month from the spring through the early fall. Use a balanced 20-20-20 crystal or liquid formulation made for orchids diluted with water according to label directions. Pour over the roots and planting medium until saturated and allow the excess to drain away.
Always err on the side of less, rather than more, fertilizer as the salts can build up in the medium and on the roots, thereby stressing or damaging the plant--which can delay bloom.
Water your cymbidiums regularly once a week with tepid water. Provide ambient humidity around the plant between 50 and 80 percent at all times to create the optimal conditions for health and bloom. Use a mechanical humidifier, water and pebble tray, daily misting or some combination thereof to achieve this standard in your particular climate.
Cold treat your cymbidium orchids in the summer and fall to trigger their bloom cycle. Keep your cymbidium in a location where night temperatures hover between 40 and 55 degrees Fahrenheit and day temperatures are warmer but remain under 70 degrees Fahrenheit. Alternatively, ice down the planting medium nightly in summer and early fall where you do not have access to a cool night location.
Lay several cups of ice cubes on the planting medium and roots each night to trigger bloom. Store the orchid outdoors in the fall when temperatures drop to suit the orchids' needs, so ice is not required.
Transplant your cymbidiums into a new slightly larger pot with fresh planting medium once every 3 to 4 years in the early spring to support a blooming environment for the roots. Cymbiums like some crowding of the roots in their pot so increase the pot size by no more than 3 inches. Be sure to remove all of the old planting medium from between the roots, and use only coarse bark-based orchid mix suited to epiphytic orchids.