Click HERE For Equitant Oncidium or Tolumnia care
LIGHT: Oncidium like indirect or filtered light. In the greenhouse 800-1500 foot-candles is best for most mature plants. An east facing window or a shaded south or west window will do very nicely. You may also supplement with artificial light, such as grow lux, if needed.

WATER: The number one rule is water early, by doing so you will avoid sending you Oncidium to bed with water standing on its leaves. Number two rule is the smaller the pot the more frequent the watering - to elaborate try once a week for six inch and larger pots, every four to five days for smaller pots. The newer the medium and the dryer the air the more often the watering, if your medium is two years old it will be breaking down (see below) and will need watering less often. The object with Oncidium is to keep the roots moist but not wet.

FERTILIZER: There are many "methods" of fertilizing your Oncidium. To keep it simple use a balanced formula (such as 7-9-5 or 20-20-20) at half recommended strength. In any case it is a good idea to leach your plants at least once a month. This is accomplished by watering with plain water until water flows out of the pot for a while. The purpose is to rinse out any salt build-up. Speaking of salt do not use water softened with salt to water any plant. Never feed a dry plant. Withholding fertilizer or using a bloom type (such as 3-12-6) starting in November will increase chances of a good blooming the following spring.

TEMPERATURE & HUMIDITY Ideal temperature range is 60° - 80°. Larger plants will tolerate up to 85° provided humidity is kept at least 50%. Basically most homes will provide the required temperatures without any adjustments. If you can lower the night temperature to between 50° – 55° for about three weeks starting in November it will increase your chances of a good blooming the following spring. Oncidium enjoy a relatively high humidity. Humidity in the home can be increased by putting the plants on a tray that can hold a small amount of water, such as a Humidi-Gro tray. You can also use a shallow container filled with marbles or stones but be careful that the bottom of the pot is always above the water, as they do not like to have "wet feet". A daily misting of the leaves and aerial roots will also help.

REPOTTING: Potting in medium bark recommended for orchids will suffice; though there are many "sophisticated" mixes used by growers. It is recommended that you soak the bark overnight in water with 1/2 tablespoon of Physan per gallon of water. The reasons for repotting are either the old mix is breaking down (literally getting soft and looking more like dirt), or that the plant has outgrown the pot. Take the plant out of the pot carefully and gently clean off all the old bark and the dead roots (usually found right under the center of the plant). Choose a pot that is just large enough to get the roots into it without "cramming" them in. Don't make the mistake of over potting; be willing to repot every year or two. Make sure that there is a good set of drain holes in the pot, pot shards or Styrofoam "peanuts" in the bottom of the pot will keep the drain holes open. Hold the plant in the center of the pot with the lowest bulb about 1/2 inch below the rim of the pot, add the appropriate sized bark and tap the pot to settle any excessive air pockets, do not press too hard on the bark as your Oncidiums roots need room to breath. Fill to just above the bottom of the lowest bulb. You might now mark the plant stake with today’s date, helps us remember when we last read this section. Unless it's really necessary don't repot when the plant is in bloom as it may cause bloom drop.