Most Cattleyas are grown in greenhouses, but
they may be grown successfully as house plants.
Except for humidity and light, conditions
in the home are generally favorable for Cattleya
growth. In the spring, summer, and the fall
they may be grown outside if protected by lath or
shade cloth. They need 40%-50% of direct
sunlight. In San Diego County there are
many areas where you may grow Cattleyas outside
all year. Keep in mind the few hot days,
and the few cold nights that you may experience
during the year might require some extra effort.
TEMPERATURE: The optimum
range for Cattleyas is 60 to 80 F.. They
will grow satisfactorily between 55 and 90 but
temperatures above 90 can be very harmful.
WATER: Because Cattleyas can
stand long drying periods, they like to be
alternately well watered, then dried out. A
mature plant needs a good watering about once a
week. Smaller plants will generally need
water about twice a week during the growing
season (March to October).
HUMIDITY: The ideal humidity
for plants in a greenhouse is 40% to 80% or even
above. Most greenhouse humidistats are set
at 50% minimum for Cattleyas. Plants
outdoors should be misted daily during hot or dry
spells. In the home, humidity is obtained
by placing the plants on gravel in a tray
containing water. The evaporation of water
around the gravel provides sufficient humidity.
LIGHT AND SHADING: Give the
plant as much light as it will take without
burning the leaves. The foliage should be
light green rather than dark green. If kept
in a sunny window, it may be necessary to shade
with a lace curtain, cheese cloth or similar
material. If the plant refuses to flower,
it may be a sign of not enough light. There
are of course other factors that do affect the
flowering of Cattleyas. 2500 to 3500 foot
candles of light are acceptable.
POTTING: The media most
commonly used for potting Cattleya orchids is fir
bark. Some growers incorporate small pieces
of charcoal, perlite or volcanic rock in their
mix. This is for better drainage. On plants
up to 3" pot size use 1/8 to 1/4"
(fine) orchid bark. 4" pots and up,
use medium size bark. It is recommended to
moisten the media before potting. Also,
REPOTTING AND DIVIDING: Any
of the three conditions are necessary in
determining when to repot Cattleyas:
- The roots are growing over the edge of
- The plant is starting to make new roots
at the base of the old pseudo-bulb.
- If the plant is not doing well, and the
bark in the potting mix is broken down,
and it has finished flowering, then
Generally, if your plant is growing well
repotting every two years will suffice.
When you do repot and divide allow 3 to 5
bulbs to a division. This size will allow
the division to fit into a 5" or 6"
pot. In order to allow for two years
growth, place the division with lead growth in
the center of the pot. Surface of the mix
should be about an inch below the top of the pot.
In making the division make a clean cut
with a sterilized cutting tool.
Remove all dead roots and pack the new mix
firmly about the remaining roots. Place the
plant in a well shaded warm, humid area.
Spray leaves lightly daily. Resume
normal watering after the plant has started to
make new roots.