Culture
Oncidium orchids are considered intermediate to warm orchids, requiring temperatures of 70 to 85°F during the day and 55 to 65°F at night. They can tolerate temperatures up to 95°F if humidity and air movement are increased. Plants may be placed outdoors in summer in a shady location. Repot in a well-drained, orchid bark mix every two years in the spring when new growth is about half mature. Position the plant with the newest growth farthest away from the edge of the pot. Maintain humidity at 50% or greater and feed weekly after thorough watering with a balanced fertilizer at quarter to half strength. When flowers have faded, remove the flower spike at its base.
Noteworthy Characteristics
Oncidium is a genus of around 750 species of orchids. Hybrids are commonly cultivated for their showy flowers. The erect flower spike is long and branching, bearing many small flowers, and originates from the leaf axil of recently matured growth. The flowers are small, usually 1" wide. Plants in the wild are epiphytic rather than parasitic, meaning they grow on the branches and trunks of trees only for support and not for water or nutrients.
Genus name comes from the Greek word onkos meaning a tumor.
Problems
Relatively trouble free, but check for scale and mealybugs.
Uses
Oncidium orchids are attractive plants for the home or greenhouse.