Oncidium Papilio (Psychopsis - The Butterfly Orchid) Culture
Oncidium papilio (psychopsis) and its hybrids have a few preferences that when met will increase the strength of the plants and give you more flowers of higher quality. Flowers of the standard color form are bronze and gold and very reminiscent of a butterfly, hence the nickname. The rare alba form is that which flowers as yellow and cream. Bloom stems are sequential, and flowers are produced generally one at a time with the future buds maturing behind the current bloom.
Potting Media: You should use a media that drains well with ingredients like tree fern and charcoal that help "open up" the mix. The roots on these plants will not tolerate sour conditions, but the plants do not like to be repotted frequently. Using a rapidly draining mix will add to the length of time you can keep the plants in the same container. When you do repot, do so in the spring when new roots appear. This may come at the same time as new spikes. Removing spikes when repotting will allow the plant to use more of its energy to get established in its new container.
Repotting: After removing the plant from its container, soaking it in a solution of Superthrive, Dyna-Grow KLN or another root growth stimulant for a few hours and then allowing it to dry somewhat for a couple of weeks out of mix before repotting it should help initiate sufficient new root growth. During this period the plant should be misted on clear, sunny mornings, but not watered otherwise. Clay pots also work well as they allow the mix to dry quickly and not stay overly damp.
When you repot, take care to get the crown of the plant just below the potting mix line so that the roots emerge into the mix, not into the air. The plant should be firmly settled into the mix so that it does not "wobble" at all. Go light on the watering until new roots reach about one inch in length.
Watering and Fertilizing: One reason for watering so lightly at the repotting stage is that these Oncidiums can be lost rather quickly to fungal or bacterial infections, both of which are inhibited by dryer conditions. Take care not to break the surface of emerging leaves when repotting, as this gives easy access to the open tissue for troublesome spores. Any lesions should be quickly treated with your fungicide/bactericide to prevent infection. Fertilize most heavily when in growth, and heavier when growing in brighter light, but do take care to keep fertilizer deposits from gathering in the crease of emerging growths. Use whatever fertilizer you use on your other orchids, but remember that less nitrogen will be needed when growing with less fir bark in the mix.
Air and Humidity: Good air movement is essential to help your plants dry faster between watering and will also help to prevent the stale, humid atmosphere in which dangerous pathogens thrive. High humidity in the air is especially beneficial, but makes good air movement even more important. If the air is humid, you will have to water a bit less frequently, but do not think of humid air as a substitute for water to the roots when the mix dries out.
Light: Psychopsis papilio and its hybrids grow and flower well for us in quite a range of light. We grow them with both Phalaenopsis and Cattleya hybrids and have good growth and flowering in both the low and the high light greenhouses. When growing in lower light, it is more important to keep a watch on the roots to be sure they are not staying wet.
Note: This guide is only applicable to Oncidium papilio (psychopsis). For other varieties, please click on one of these links: