LIGHT: Oncidiums do best in a bright, very well-ventilated spot and often produce more flowers if grown in an almost full-sun area. In Florida, they should be placed in such a spot in winter and acclimatized to the sun. Basic necessities are much like Cattley
TEMPERATURE: Most of the Oncidiums do best under temperatures from 50° (min.) to 80° (max) – the medium range. There are others which like cooler or hotter climates depending on their origin, but these are rarer species.
WATER: Oncidiums do well when grown on cork or on bark, since they prefer to be PERFECTLY drained and to have their roots dry within a couple of hours. Some types prefer small baskets or pots. While rapid growth takes place, they like to be watered often, 2x to 3x a week, but less water should be given for several weeks after the growths are complete. Misting with a weak plant food solution is helpful during sunny mornings.
FEEDING: These plants want regular feedings of a balanced fertilizer such as Peters 20-20-20 for those growing on slabs or in tree fern. A ½ strength solution once each week or full strength every 2 weeks is suitable.