Oncidium orchid's light needs can vary greatly between nearly direct sun to slightly shaded depending on species. Generally, plants with thicker leaves can withstand more light than those with thinner leaves.

Depending on the plant, give oncidium between 2000-6000 foot-candles of light (shade to part sun). Inside the home, place plants in a east, south, or west window.

For those plants that require high amounts of light, it may not be possible to achieve indoors without the help of LED or artificial lighting. Use an LED that emits >10000 lumens (900 foot-candles) about 1 to 2 feet from the plant to supplement window-sill growing.

Oncidium are typically intermediate-warm growers and will do best in a range between 75-85F during day and 55-65F at night. Indoor room temperature works fine for these plants!

Plants can tolerate temperatures above 90F for short periods but should be kept watered well or allowed to cool at night time to keep them happy.

As with lighting, watering will also vary greatly depending on the species being grown. Generally, oncidium with thin roots will require more frequent watering - some may not want to dry out completely - and some with thicker roots will require less frequent watering. A good rule of thumb is to ensure at least half of the media dries before watering again and ensuring there is plentiful air reaching the roots.

Oncidium will show you when they are not receiving enough water - their pseudobulbs will start to shrivel and the leaves will become "accordion" like.

These plants are rather susceptible to fungal issues and watering the leaves and other parts of the foliage outside of the media should be avoided to prevent fungal infections.

Mounted oncidium will need much more frequent watering than their potted counterparts - water mounted plants at least once per day, or twice if the temperatures are above 85F.

Never use ice to water orchids!

Oncidium generally do best in high humidity environments, especially plants with thin roots and thin leaves. Keep humidity between 50-60% or higher.

With increased humidity, increase airflow!

Fertilize regularly in the growing seasons to produce healthy, vigorous pseudobulbs. For potted plants in bark based media, use a high nitrogen formula (30-10-10) at 1/4 to 1/2 the strength on the label. For mounted plants or plants in moss, use a higher potassium or bloom-booster formula (i.e. 10-30-20) at 1/4 to 1/2 the strength on the label. This should be used as spikes are forming.

Reduce and/or stop fertilizing in the fall and winter months.

Potting should be timed to align with new growths, which is typically in the spring for oncidium. Some oncidium grow year round, and as such should be repotted when they are not in spike or flowering.

When new growths start, the plants will also produce new roots, which is the best time to repot so that plants can bounce back quickly from having their root systems disturbed.

Many oncidium have thin roots that require an evenly moist environment - give these plants a breathable mix of fine bark with chopped sphagnum moss, or they can be potted directly in moss for those growing in a drier environment such as inside the home.

Position the newest growths farthest away from the edge of the pots to allow room for new growth.

Use a sterile cutting tool when cutting any plant parts, including dead roots.