Oncidiums are native to the tropical Americas and stretch
from southern Florida to Southern Brazil. They are a very
diverse genera of orchids. Their individual culture is dependent
on their native regions.
Most oncidiums grow well with night temperatures of 55F to
62F and day temperatures of 70F to 80F. They are intermediate
in temperature range. They will tolerate summer heat provided
they have good ventilation.
Oncidiums that have tender thin foliage require bright light
with some filtered or dappled sun. Their root zones are fine
and they have small pseudo bulbs. Do not allow them to remain
dry between watering.
Another variety of oncidium is called the mule ear variety.
It has very thick leathery foliage in the shape of a mules
ear. It requires direct sun for a minimum of four (4) to six
(6) hours per day. This variety enjoys going very dry between
The equitant oncidium is a small compact plant with thick
fleshy foliage that grows in a fan shape. It requires filtered
sun for about four (4) hours per day. The roots of the equitant
are very fine and the plant does not have any pseudo bulbs.
It will require more frequent watering and does not like to
stay dry for any length of time. The equitant oncidium will
bloom for many months out of the year. When all of the blooms
are spent do not cut the flower spike. The spike will usually
develop more buds out of a lower node if it is in the proper
light. Only cut the spike when it has become brown and dry.
This variety will also do very well in a light garden using
four florescent tubes.
Growing your oncidium orchid in a hydroculture planter takes
all the guess work out of when to water and how much. Water
only when there is no water left in the outside pot. Depending
upon which oncidium you are caring for will determine whether
to leave it dry for a day or two between watering or if it
should be watered as soon as all of the water is depleted
from the outside pot.
Mix the nutrient solution as per packet directions. You may
store the nutrient in a gallon plastic bottle to be used when
ever it is time to water your plant. It is best to keep it
at room temperature and out of direct sunlight.
Pour the nutrient slowly into the clay pebbles next to the
water level indicator. Water until the indicator reads about
half way between the "min" and "opt" level.
Always be sure there is no water in the outside pot before
Once a month separate the culture pot from the outer pot
and run tepid water through the clay pebbles and over the
foliage to remove any dust and mineral salts that will accumulate
in the root zone. Return the culture pot to the outer pot.
Water as per above directions according to the variety of
oncidium that you are caring for.