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
todays 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. |