I love Oncidium orchids – all of them. This is a complex and difficult genus (group) with many of the over 330 species being reclassified as this is being written. Growers are asking that this genus be split into multiple genera (groups) starting with the sub-tribe Oncidiinae of the orchid family.

Abbreviated as “Onc.,” these stunning orchids were first described by Olof Swartz in 1800 with the orchid Oncidium altissimum, which became the species type. As a major flower hobbyist, he discovered and described many orchids for us.

The name for the Oncidium orchid came from the Greek word “onkos” which means “swelling.” The swelling comes from a callus at the lower lip. These plants grow throughout the tropical and subtropical Americas and are classified as terrestrials (growing across the ground from tubers), epiphytes (growing on another plant like a tree) or lithophytes (growing on rocks). Their natural habitat stretches from northern Mexico all the way to the Caribbean through South America and to some parts of South Florida. They like seasonally dry weather.

The many varieties of Oncidium orchids bloom in spectacular shades of yellow, white, red and pink and have an exciting ruffled edge on their petals. The lip on this orchid is enormous and partially blocks the small petals and sepals. Some plants are very long, growing to a height between 3 to 5 m (118” to 200”), producing incredibly beautiful sprays of flowers and slender leaves. Since they thrive in nature in diverse habitats, you can produce lovely Oncidium orchids by learning what they need to thrive in your neighborhood and providing these wonderful species with the proper care. They need cool to warm conditions with moderate to bright light and watering is easy. Just water right before the planting mix starts to dry half way down in their well-drained mix such as medium fir bark.

Known as spray orchids among many florists, they are so varied and so easily hybridized that there are hundreds of thousands of excellent hybrids in the Oncidium alliance. They can be divided into three distinct categories with their growth patterns. Some of the orchids have green pseudobulbs and long racemes with small flowers and a dominant lip and are mostly a golden yellow with and without reddish-brown touches. Another group has very small pseudobulbs and has stiff, erect solitary leaves that act as water reservoirs. They have long racemes with yellow flowers that fan out at the top. The sizes can vary from miniature plants of only a couple of centimeters (less than an inch) to giants with 30 cm (40 inches) leaves. These are commonly known as Mule Ears and classified as Psychopsis.

If you are interested in potting these gorgeous plants, you will need a pot that drains well and a fine grade of orchid potting mix for orchids with fine roots and a coarse mix for plants with larger roots. As mentioned, they like plenty of light but not so much that it can cause the plant to shrivel. If your Oncidium has thick leaves, it likes more light. Room temperature between 55° and 80° F is perfect. Water during the growing season letting the soil dry out a bit and reduce watering during their dormant period but don’t stop watering or the bulbs will shrivel up. Fertilize with an orchid fertilizer twice a month with plant food recommended by the grower. A few tips to remember are that if the leaves are yellow, they’re getting too much light. If the leaves are dark green, it needs more light. Aim for a light green color.

Orchids may have been around 80 to 100 million years ago during the time of dinosaurs. All types of orchids are sought by collectors and many orchid societies have been established all over the world. One of the most prominent is the American Orchid Society which serves to encourage collection and cultivation of orchids. Many groups concentrate on conservation so that these magnificent flowers can be enjoyed for another 100 million years. In the meantime, can’t you imagine a table full of these Oncidium orchid varieties on your sun porch? Remember, you can also grow them attached to trees or on rocks.

The following video displays the Oncidium orchids in all their glory!

We’ve given you lots of information about the magnificent Oncidium orchid already but if you want or need more, please follow the links below:

For everything you have ever wanted or needed and for everything that you will ever in the future want and/or need about orchids and orchid plants, use this Orchid Care.org as your number one source because it’s detailed and comprehensive and is always being updated.

Filed under: Orchid Species

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