This week we visit the Dorothy
Chapman Fuqua Orchid Center at Atlanta Botanical Garden
(ABG). Ron Determan is the Conservatory Superintendent and
is in charge of all facets of indoor horticulture. He also
is the mastermind behind the engineering of the building.
To provide the orchids a high altitude elevation environment,
similar to the cloud forests of their native environment,
5 or 6 thousand feet above sea level - that of the Andes
or Southeastern Asia - he has borrowed technology found
in the textile industry. They use washing systems and Ron
has applied it for the first time to greenhouses at ABG.
He's integrated that system with other systems such as high
pressure fog, cooling, roofs that open, etc.. This allows
these beautiful Orchids to grow in the unlikely environment
of Atlanta, Ga.
We view plants from three areas the Andes, the flat top
table mountains in South America and Southeast Asia - Mount
Kinabalu, the highest mountain in Borneo. We view a rock
wall made with real rocks, rescued from a D.O.T. bypass.
On this, Andean Mountain plants are plentiful and unusual.
The Southeastern Asian Mountain area has many plants as
well. We specifically discuss Pitcher Plants, Nepenthes
Lowii, carnivorous plants that grow only in these mountains.
In another area they simulate the Tepuis, the flat top table
mountains in southeastern Venezuela and Brazil. The elevation
in that area would be 6,500 feet or so. There are plants
in/from this environment that wouldn't be encountered anywhere
else on earth. One might find Carnivorous Bromeliads, relatives
of Saracenias, Eucathalarias and of course, Orchids. They
survive in a very thin layer of soil, a little sand and
possibly a little organic matter. The soil is very well
leached, practically no nutrients. The area would be wind
swept and the plants hang in clouds part of the day. The
roots cling to crevices in rock formations.
Becky Brinkman is the Orchid curator at ABG. She shows us
some of her favorite Orchids. Cattleya Dowiana is from Costa
Rica, it is a velvety crimson color with gold veins and
purple margins and it has an incredible fragrance. It requires
a little more light and warmth than most so she hangs it
close to the glass. It could be grown in a greenhouse or
atrium. We next view Coryanthes Elegantium, called a Bucket
Orchid because the lip, which is the most prominent petal,
is shaped like a bucket and it fills with liquid. This plant
has a very peculiar pollination mechanism, it produces a
powerful fragrance that attracts a particular species of
bee, an Euglasian Bee. There are large iridescent tropical
bees that seek this fragrance. When they land on the orchid
they scratch the surface to obtain the fragrance which is
a liquid. Some of the fragrance is converted into a Pheromone,
some bees then loose balance and fall into the liquid and
do several laps across the Orchid flower. The bee can no
longer fly because his wings are wet so the only way out
is through the little opening in the back and that is where
the pollen is stored. By crawling through the opening the
bee picks up the pollen.
Another Orchid has a different pollination mechanism. The
bee lands on the Orchid that has a downward pointing antenna,
almost like a trigger. The pollen is held under pressure,
when the bee bumps the trigger the pollen is shot onto his
back and is held there by a sticky adhesive. A tropical
cousin of the Lady Slipper is Paphiopedilum Lowii. It is
native to Malaysia and Indonesia. The shape of both of these
flowers is similar and both like a similar environment,
the forest floor, in the shade or in crevices among rocks.
Paphinia Herrerae has beautiful white, translucent petals.
At ABG all are offspring of one plant brought from Equador
to ABG in 1990. The ABG Orchid Center is the largest public
display of Orchids in the U.S. They have a formal display
area where they maintain a year round display of Orchids
and flowers. Another area simulates the natural habitat
of different Orchids from Mexico or Madagascar, rocky habitats,
wetlands or meadows. It is all beautiful.
Mike Wenzel is Tropical Accessions Manager at ABG, that
means he is in charge of cataloging and tracking thousands
of plants. Mike shows us some easy to grow Orchids. The
Phalaenopsis, or Moth Orchid, handles indoor temperature
ranges very well. They will survive and bloom in a lower
light situation although they do need light to flower. They
typically bloom in the spring and some shown have largish
sized flowers. Phalaenopsis Bellina is a species that you
might see growing on the side of a tree in southeast Asia.
It is a parent of a hybrid Phalaenopsis. It too is easy
to grow, has a different style and a spicy fragrance. When
watering Orchids remember they like to dry out a little
between waterings. Don't let them get bone dry, but when
slightly dry, soak them, then allow them to drain. Drainage
Some Orchids have a bulb-like feature on the bottom called
pseudo-bulbs. These organs help store water for use when
water is not available. Some Orchids have these, some don't,
a Moth Orchid doesn't.
Hybrid Miltonia, Honolulu tends to bloom in the summer.
The hybrid shown is a beautiful purple color and has many
spikes. It has the pseudo-bulbs, thus doesn't need watering
often. If one wants to get the plant to rebloom, fertilizer
is not necessarily the answer. Often times light is the
biggest issue, Orchids don't need full sun, but they do
need bright indirect light in the morning, particularly
if the plant is behind glass. They can be taken outdoors
as long as they don't get too much light, especially in
the afternoon, or too much water. Bright indirect light
Miltassia is a hybrid, has a completely different look,
almost spidery. It has a lot of browns, maroons and mauves
and is exotic looking. It too is easy to care for.
Becky Brinkman joins us again to show us how to repot Orchids.
Repotting an Orchid is easy. Remember Orchids resent root
disturbance. Their roots are designed to attach to surfaces,
typically a tree trunk. They also attach to the inside of
a pot. When they're repotted the roots tear from the surface
- the pot - and that results in injury and a setback for
the plant. There are two reasons to repot an Orchid. One
is if the plant has outgrown the pot, the second occurs
when the soil mix has broken down. Becky has assembled all
materials needed to repot- sterile sharp cutting tools,
clean pots rhizome clips and soil mix. The soil mix contains
no soil but instead fir bark, charcoal and lava rock, otherwise
known as Perlite. The best time to repot is when the new
shoot is 1 to 2 inches tall, before the roots have emerged.
Keep your eye on the new shoot because it is as tender as
new Asparagus and if you break the new shoot you've lost
a whole years growth. First remove the Rhizome clip from
the pot, invert the plant and gently tap it on the table.
Next wash the roots, this removes old soil sediment from
the root ball and allows examination of the roots. In the
case of the plant in this show the older part has started
to die back. It no longer has living roots. Remove that
portion of the plant, Becky uses the razor blade and removes
the oldest three growths from the plant. The roots were
no longer healthy. she then chooses the correct size pot.
Orchids like to have their roots confined in the pot, not
so much because they like confinement but because they like
their roots to grow on the pot itself. Make sure the plant
is snug in the pot yet still has enough room to grow for
two years. To make room for two years growth, place the
plant, not in the center, but back the old growth against
the side of the pot. This allows the new shoots room to
grow. Fill in the empty space with the soil mix, packing
it firmly insuring no air pockets. Make sure the plant doesn't
wobble. Once done, attach the Rhizome clip. It holds the
plant firmly in place. Fertilize every two weeks, watch
for pests and the plant should be good for another two years.
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