paph armeniacums culture

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Jan 22, 2008
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elmer, nj
I found this info on an orchid club website. The article was written by J. Fowlie and was published in the 1989 Orchid Digest. I include the article in it's entirety, and suggest if anyone has real interest they go to the O.D. website and purchase a back issue if they have it. Really interesting info! I plan to change my potting setup with this info and the other presented in the recent parvi culture thread with the armeniacums and micranthums in baskets.

The Culture of Paphiopedilum armeniacum
by Aranda Nurseries
J. A. Fowlie, M. D .

For some time in Southern California we have imported and grown Paphiopedilum armeniacum which
usually flowers in the spring with its magnificent golden flowers. If plants are obtained with the flowering hormone in place, they seem to open between March and May in artificial cultivation in California. However, there is a notable lack of flowering on the following and subsequent seasons, despite attempts at cultivation to simulate the cold climate where it comes from in nature, i.e. growing out of doors near the coast without any heat, growing it inland in Southern California in a non- heated greenhouse. . . all produced somewhat better results.

About the Plant in Nature
This species is a native of Bijiang on the headwaters of the Mekong River in Western Yunnan Province of Southwest China. As such it is perhaps our most northerly occurring Paphiopedilum species. Its situation of climate is partially ameliorated by being in a southward facing river valley, which in winter is bright and sunny, protected by the Himalayas from air movement from the North during its coldest time of year. At this time it receives 36°-40° F. nights and 60° F. days and in the summer months the air moving from the Southwest monsoon courses up the river valley, skies are overcast and temperatures in a wet condition are 50-55°F. nights and 70-80° F. days. Elevation is 3,000-4,000 feet and it grows with Shian ren bi, "The Pens of God", Phaius columnaris. This orchid has a reputation for being able to survive in some of the harshest climates in China from about the 22 to the 26th parallel North Latitude. The habitat of the P. armeniacum is about the 26 degree North latitude region. It is thereby well north of P. wardii in the upper Salween Basin (By comparison 26°N. Latitude on the Pacific Coast traverses through Loreto in Baja California and near Los Mochis on mainland Mexico, just where epiphytic orchids commence.) The climate might be said to be perennial spring like, as winters are bright and sunny with full, weakened sun lower on the southern horizon and summers are softened from their harshness by cloudy skies and prodigious rainfall. The plants hence are wet at the roots in summer; whereas in winter only water condensed by the limestone trickles to the roots. This is a function of the limestone heating up in the hot son during the daytime and at night cooling off so fast that moisture in the air condenses on it and runs down its surface into the cracks and fissures where the P. armeniacum is growing. Spring is very foggy in the habitat during the night and early morning.

Aranda Orchids is situated in the heights of Terresopolis, just east of Petropolis in the Organ Mountains of Brazil and just less than 23 Degrees South Latitude. It enjoys a comparable climate with bright, sunny winters of intense sunlight and blue skies, ameliorated only by the position of the sun's angle lower on the northern horizon. During the summers the sun is more intense but there is much more cloud cover and raininess with cold, foggy springs. As a net result Mr. Fernando Parga of Aranda Orchids is having great success in growing and flowering the P. armeniacum, cultivated in an unheated greenhouse. He is using some shading on the roof, but basically the plants on the benches are getting very bright light all winter long when the plants are in a cold and torpid condition. During spring and early summer it is cool in his greenhouses, 60-70 with understandable extremes in hot weather, which he can control with ventilation. His humidity can be kept rather high. . . compared to California. His compost consists of three layers. The lower most layer is broken chips of local granite to 1/3 full. Next comes a layer of "forest humus" consisting of dead leaves of local hardwood trees.
Topping this is the third layer of live, sphagnum moss, kept alive by using local water, which is under
300 parts per million Sodium. (Moss will come alive and stay alive with water 300 parts per million
sodium or less).
He uses no organic fertilizers with the exception of some mamona cake initially in the leaf
detritus layer in which he has also put ground up oyster shell. We have previously written that
calcareous lady-slipper orchids of warm climates derive little if any Calcium or Magnesium from the
native stone to which their roots are attached since the rains are warm. Therefore, it does them little
good to use limestone chips in the compost, i.e. P. ang x thong, P. godefroyae, P. leucochilum, P. exul,
P. chamberlainianum, P. liemianum, P. glaucophyllum, P. moquetteanum, P. victoria - mariae all grow
on limestone but except for the last named they grow at low elevations with warm rains and limestone
is less soluble in warm water than it is in cold water.
At Aranda Orchids the sunlight impacting the live sphagnum mosses turns them a lively green
color and they grow prodigiously. They support algae that fix atmospheric nitrogen into amines and
this in turn feeds the roots in the leaf mould layer beneath.
Perhaps, as a consequence of the above factors the plants enjoy a wealth and vigor of growth
seldom seen anywhere else. The roots proliferate and a seedling in a short time reaches prodigious
size, even contrasted to jungle plants. The percentage of annually flowering specimens has to be one of
the highest in the world.
Undoubtedly, growth of seedlings from pod, which has proved difficult to this time may prove a
function of this kind of treatment.
Since so many hybrids will eventually be made from P. armeniacum it will be to all of our
benefit to learn how to eventually grow and flower it better. The editor invites observations from
readers on any other so successful with the growth of this species.
Orchid Digest, Jan.-Feb.-Mar., 1989

by the way, does anyone know of an alternative to mamona cake (pressed castor bean meal) in the u.s.?