Their natural bloom season is during the winter, which is ideal if your plants are indoors for display. The bloom is triggered by a combination of falling temperatures and reduced water.
Light
During the growing season, cymbidium orchids appreciate dappled sunlight. If your orchids are outdoors, make sure they are not in direct sunlight, as this can cause burning on the plant. A few hours of morning sunlight paired with shady afternoons should be perfect. If you are growing your orchids indoors, a southeast- or east-facing window is ideal. Under the proper light conditions, the leaves should appear apple green as opposed to dark green. A dark green plant is likely not receiving enough sunlight to provoke a good bloom.
Soil
Cymbidiums are semi-terrestrial orchids. They naturally grow in loamy humus, sending thin roots into the soil. Thus, they are perfectly suited to conditions that are easily replicated at home: a rich, loose, organic potting mixture. Most growers recommend using a combination of fir bark, perlite, peat moss, and other loose organic material for cymbidium orchids. A commercial paphiopedilum orchid mix will usually serve these plants well.
Water
Water these plants frequently during the growing season (i.e., the spring, summer, and fall). And remember the purer the water, the healthier the plants. Accumulated salts from tap water can cause damage, such as leaf-tip dieback, a condition in which the leaf tips turn black and die. So make sure to flush water all the way through the potting mixture. During the winter bloom, reduce watering. However, don’t let the plant completely dry out. Instead, keep the potting mixture slightly damp to the touch.
Temperature and Humidity
Cymbidiums are considerably more tolerant to cold weather than some other popular orchids. The larger varieties of cymbidiums need an extended period of cold to provoke a bloom, while the miniature varieties aren’t quite as dependent on cold weather. Cymbidiums have been known to briefly withstand freezing temperatures, though frost will eventually kill them. Nights with temperatures down to 40 degrees Fahrenheit should be fine. On the other side, cymbidiums can also withstand summer heat without wilting, as they are suited to the temperate regions of Asia where there is considerable variation in seasonal and day-to-night temperatures. Outdoors, these orchids can tolerate most humidity levels except for very dry climates. And indoors, they like a humidity level of around 40% to 60%. If you need to raise the humidity, you can place your plant’s container on a tray of pebbles filled with water. Just make sure the bottom of the container isn’t touching the water, as this can lead to root rot.
Fertilizer
During the growing season, feed with a weak orchid fertilizer bimonthly. Or scatter slow-release pellets in the growing media at the beginning of the season. Be careful to avoid a high-nitrogen fertilizer, as this can cause rapid foliage growth at the expense of the orchid’s blooms.
Common Pests and Diseases
A well-grown cymbidium should be resistant to most insects and diseases. But as with all orchids, there is some risk of aphids, scale, and other insects. Treat as soon as possible with insecticide products, following label directions.
Varieties of Cymbidium Orchids
There are numerous species and hybrids of cymbidium orchids. They include:
Cymbidium dayanum: Known as Day’s cymbidium or the phoenix orchid, this species sports white flowers with stripes of burgundy.Cymbidium erythrostylum: This plant is native to Vietnam and features white flowers with red in the center.Cymbidium tracyanum: Known as Tracy’s cymbidium, this orchid has large, fragrant, yellow-green flowers with brown stripes.
