The Oncidium orchid, also known as the Dancing Lady orchid, is one of the easiest orchids to grow at home, although it requires more light than other varieties. The plant produces long-lasting, fragrant yellow flowers about once per year when proper care is provided. Oncidium orchids are native to tropical climates and are typically grown indoors throughout the United States. Oncidiums have become increasingly popular over recent years for their ease of care and adaptability to household conditions.
Select a spot in a sunny, south-facing window for your Oncidium orchid, and leave it there as much as possible. Orchids perform best when they are left in one place. Alternatively, place four 40-watt lightbulbs about 12 inches above the plant to provide adequate light.
Keep Oncidium orchids at a constant temperature of 75 to 85 degrees F during the day and 60 to 65 degrees F during the night. Never allow temperatures to exceed 85 degrees F or to drop below 50 degrees F.
Water your Oncidium orchid plant about once every 10 to 12 days, allowing the growing medium to dry out between applications. Do not saturate new growth at the base of the plant with water, and never allow the plant to stand in water, as rotting could occur.
Keep the relative humidity around Oncidium orchids at 55 percent to 75 percent for the best results. Place the plant's container on a tray filled with water and gravel, or place a humidifier near the orchid to raise the humidity. Use a humidity thermometer to monitor humidity levels.
Feed Oncidium orchid plants twice per month using a 20-20-20 NPK (nitrogen, phosphorous, potassium) houseplant or orchid fertilizer. If the plant is grown in a bark-based potting medium, feed twice per month using a 30-10-10 NPK fertilizer diluted to one-quarter the recommended strength.
Repot Oncidium orchids once every two years in spring. Remove any dead roots, and discard all the old growing medium. Place the plant in the empty container, and fill the container with fresh medium-to-fine fir bark, being careful not to damage the fragile roots.