among the most popular orchids. Their culture is
as the basis for comparison with other types of
orchids. Cattleyas and their
related hybrids come in many colors, shapes, forms
and sizes. Culture varies only
slightly among most of these. This sheet is a general
guide to basic cattleya culture.
Like many other cultivated orchids, cattleyas are
epiphytes, or air plants. They
have developed water-storage organs, called pseudobulbs,
and have large, fleshy
roots covered with a spongy, water-retentive velamen.
They are accustomed to
being dry at the roots between waterings, and therefore
should be potted in freedraining
L I G H T
Light is the most important factor
in growing and flowering cattleyas, whether in
or in the home. Bright light to some sun should
be given to the plants, with no direct sun in the
middle of the day. This means an east, shadedsouth
(as with a sheer curtain) or west window in the
home, and 50 to 70 percent full sun in a greenhouse
(3,000 to 5,000 foot-candles). Leaves should be
a mediumgreen color, pseudobulbs erect and requiring
H U M I D I T Y
Humidity should be 50 to 80 percent
for cattleyas. This can be provided in the home
by placing the plants on trays of gravel,
only partially filled with water so that
the plants do not sit in the water. Air should
always be moving around the plants to
prevent fungal or bacterial disease, especially
if high humidity or cool temperatures exist.
In the greenhouse, the humidity is
best increased by use of a humidifier. Evaporative
cooling increases humidity while cooling the air.
WAT E R
Water should be provided in two
the pot by watering and in the air as humidity.
Watering in the container is dictated by many criteria:
size and type of the
vessel, temperature, light, etc. Mature cattleyas
need to dry out thoroughly before
being watered again. Seedlings need more
constant moisture. Compare the weight of
a dry pot of the same size and type of mix;
it can indicate if a plant needs water by the
relative weight — light means dry, heavy
means wet. If in doubt, it’s best to wait
day or two until watering. Plants in active
growth need more water than plants that are resting.
Water below 50 F may injure plants,
as will water softened by the addition of salts.
P O T T I N G
Potting is necessary when the
the plants protrudes over the edge of the pot or
the potting medium starts to
break down and drain poorly (usually after
two to three years). It is best to repot just
before new roots sprout from the rhizome,
after flowering or in the spring. Mature cattleyas
are usually potted in coarser
potting material than are seedlings. Until a plant
has at least six mature
pseudobulbs, it generally should be put
into a larger pot and not divided.
a plant, three to five pseudobulbs per
division are required. Select a pot that will
allow for approximately two years of
growth before crowding the pot. Pile mix
against one side of the pot and cut off any
dead roots. Spread the firm, live roots over
the pile, with the cut rhizome against the
side of the pot. Fill the pot with medium,
working it around the roots. Pack firmly
and stake if necessary. Keep the plant
humid, shaded and dry at the roots until
new root growth is seen.
F E RT I L I Z E
Fertilize on a regular schedule.
In fir bark, a high-nitrogen
(such as 30-10- 10) formulation, or a similar proportion,
used. Otherwise, use a balanced fertilizer.
When in active growth, plants need fertilizer
at least every two weeks, and when
not actively growing, once a month. Fertilizer
can also be applied with every watering
at one-quarter the recommended dilution.
Thorough flushing with clear water
every month is recommended to prevent
the buildup of fertilizer salts