Caring for Oncidium Orchids
The Odontoglossum variety of orchids are becoming very popular for ease of growing and long lasting sprays of small, distinct flowers which often have unique color combinations and a pleasant fragrance. They will typically bloom once a year and can be grown in the home, as well as in asheltered area in the garden. Odontoglossum have been combined with Oncidiums and other related orchid types through hybridizing to offer a seeming endless array of striking color patterns.
Caring for your Oncidium Orchid
Temperature: Most Oncidiums and their hybrids enjoy intermediate temperature ranges: 75-85 degrees Fahrenheit in the day and 60-65 degrees Fahrenheit at night.
Light: Filtered, subdued indirect sun light is preferential. The leaves should be bright green as opposed to dark green or reddish green.
Water: Oncidiums should become moderately dry between waterings. Generally, they require more water while the new shoot is growing and less once the bulb has formed. Fertilise your plants at least once a month. Take care to keep water out of the new growth at the base of the plant. Never allow the bottom of the pot to stand in water. Never use artificial softened water.
Humidity: Oncidiums enjoy moist air, requiring a minimum of 40-50% humidity in the immediate vicinity of the plant. Humidity should be increased with higher temperatures. The ideal humidity is between 55 and 75% with as much ventilation or air movement as possible without any cold drafts. Humidity can be increased around the plant by placing the pot on an inverted saucer in a baking pan filled with pebbles, rock chips, etc and water. Keep water level below the top of pebbles so that the plant willnot have 'wet feet' from sitting in the water. Morning misting of foliage is also helpful, especially during periods of hot weather.
Repotting: Repot Oncidiums at least every two years. As a general rule, repot them when the new shoot is two to three inches tall or when new roots appear. All the old mix should be removed from the roots and any dead roots should be removed. If dividing, keep the divisions in clumps of three to five mature bulbs. Medium to fine fir bark is preferred. The base of the new growth should be potted about half an inch (no deeper) into the fresh bark. Keep the mix barely damp until you see the new roots penetrating the bark, then resume normal watering.