AAOS Study Group
******************************************************************************
by
Paige Hartman
Sixteen members of the AAOS Study Group met to discuss Cattleya orchids. Cattleyas
are part of the Epidendrum group, are sympodial and grow in Central and South America.
They are the "Camels of the orchid world." Many grow in moist forests near
the tree tops. An interesting fact is that in the 1800s they were used as packing
material in crates for other orchids. The horticulturist William Cattley was the
first to take this packing material and bloom them in 1818 "in the stove of
my garden."
Unlike the Dendrobiums we studied last time, all the 45 species of Cattleyas have
similar growth habits. They like intermediate growing conditions, daytime temperatures
should be 70°-85°F and night temperatures 55°-65°F. A south or southeast window
is best for indoor culture, or about 2,000-3,000 foot candles. Broad spectrum lights
for artificial light culture. If there is not enough light, the back bulbs will shrivel
and fall off. Light green leaves, even almost yellow, mean they've had good light.
A tinge of red around the edge is a good sign for certain types. Medium to dark green
leaves means not enough light is available. Some Cattleyas are sensitive to day length.
C. labiata needs shorter day length (12 hrs) and bright light. If they get more than
16 hours of light,
they won't bloom.
Cattleyas are very susceptible to scale. Scale spreads easily, and be sure to look
on the underside of leaves and under the sheaths. Horticultural oils like Sunspray
as well as several insecticides may be used. Follow all label directions and use
any insecticide with care, overuseage can injure the plant, and injure you too. Use
gloves and respiration protection. Using alcohol to get rid of them may cause phytotoxicity,
and doesn't kill the eggs. Infested plants may be placed in a plastic bag along with
a 1" piece of no-pest strip. Close it for 3 to 7 days. Mites are a problem in
low humidity. You need to keep the humidity level between 40-60% plus fans moving
the air. Water sitting on leaves for more than one hour can cause fungus. Sulfur
will help and maybe cinnamon directly on the spots of fungus and on the surface of
the media. Look your plants over thoroughly, and observe your plants often.
The plants need a porous media, and one suggested media is 80% fir bark plus 20%
perlite. Other growers have used lava rock (but roots stick to it), volcanic rock--pumice
or sponge rok (a man-made rock), and even gravel. A fertilizer of 20-10-10 dilute
and weekly will get you more flowers, but the fertilizer depends on the media used.
A suggestion is to let the media dry 1" deep before watering since they are
the camels and store water. Yellow cattleyas need warmer
conditions than other colors.
The fourth meeting of the AAOS Study Group took place Sunday April 6. Five of us
remembered to set our clocks ahead and attacked the topic of the Cattleya Alliance.
We appreciate the expertise of Neal Foster and his wonderful words of wisdom such
as: "The Stud Book of Orchids" (Sanders) and "the genetic crap game"
(when there is a hybrid that doesn't necessarily get the best qualities of the parent
plants). Our favorite NF saying that we could all identify with is "IFG--Instant
Floral Gratification"--meaning buy it cause you like it!! even if it doesn't
fit your growing conditions or space.
Actually, we did have a serious meeting with much information. We learned about 7
groups that are part of the alliance: Barkeria, Brassavola, Rhyncholaelia, Sophronitis,
Laelia, Broughtonia and Encyclia. Because they are all members of the Cattleya group,
they are all cross breed creating some amazing titles like Sophrolaeliocattleya or
Brassolaeliocattleya. If you can say it you get to buy it! Potinara is a 4-way cross
of Brassavola, Laelia, Cattleya and Sophronitis. It flowers frequently, typically
3 times a year and is happy in intermediate temperatures.
Barkeria is an interesting group that is partly deciduous. Pringle brought her plant
and we discussed roots growing outside the pot and what to do when they dry up and
get ugly (cut them off if you're sure its dead). Brassavola is a group "named
after some Italian" and are easy to grow. They come from South and Central America
and grow in tree tops with high light. Brassavola digbyana is noted for its frilly
lip and has been responsible for the frilly lip in many hybrids. Laelias like clay
pots that dry out quickly. There are 59 species of Laelias. In nature Laelias grow
in Brazil, Central America and Mexico, but not in the areas between Brazil and Central
America. Why not? Sophronitis is the cooler growing plant of this group. It can survive
temperatures down in the high 40s. It likes a high humidity and fresh potting medium.
Sophronitis coccinea is a beautiful, tree dweller, but can be difficult to grow.
It has 3" flowers on a 4" plant. Broughtonia is a warm grower from the
Caribbean. Full sun and a moist, but not soggy, medium is appreciated along with
mounting on a slab.
In general the plants in the Cattleya Alliance like intermediate temperatures: 55-60
degrees at night and 65-70 degrees in the day. Humidity of 40-60% is ideal. The plants
like bright light, but not direct sun. Pot your plants in fir bark that is kept moist
but not soggy. Misting often creates a higher humidity. Be sure to let the plants
rest during their dormant stage--just after blooming has finished.
The study group will meet on June 7, the topic is native orchids, in preparation
for our field trips. Have a question? Call Paige 426-2704.
******************************************************************************