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ORCHID CULTIVATION


  Basics

Phalaenopsis stuartiana

Unfortunately, the easily acquired orchid has the unwarranted reputation of being difficult to grow - fussy, unforgiving plants that need a home built like a misty cloud forest, with periodic cloudbursts, insects, and the occasional jaguar. Some people devoted bedrooms or basements to their orchids, while others have constructed glass houses with different climatic zones potting rooms, and Mozart  piped in so soothe the soul and presumably fortify the plants.

But you can start simply with orchids, raising a few plants on the window sill, outdoors in spring and summer, or under fluorescent lights, and discover that orchids are not fussy at all.

In fact, since they had colonized all corners of the earth assures that there is an orchid for any natural environment and makes them very forgiving and rewarding in cultivation. In this section we review the fundamentals of light, temperature, watering and fertilizing, humidity, air circulation and potting, and then comment on the pests and diseases which you might encounter in your collection. There are refinements in culture of particular species are discussed under individual entries in the A-Z menu.

 

There are many excellent books on orchid culture, many periodicals such as The Orchid Review and the American Orchid Society Bulletin provide news of helpful products and techniques, advertisements for plants, and enduring articles of interest for the orchid-growing community.

Internet search is not always reliable source of information - first, common mistakes are being copied and multiplied without reiview and often people share experiences that are only tied to their specific growing conditions. After all if what you are doing is somewhat working don't fix it, simply because someone says different in a blog.

The best source of information and plants is your local orchid society. The camaraderie and shared experiences enrich the hobby even more. List of orchid societies in your area could be found here

In orchid growing there are two guiding principles that underlie all else. If you memorize and practice them your success rate will rise exponentially as the months and years pass.

First, the most important thing you can do is buy sensibly: purchase plants that suit your growing conditions. If you live in a tropical climate, then buy warm-growing plants rather than alpine or cloud-forest plants. Within certain limits and without breaking your budget you can alter the conditions of your growing area to suit the plants, such as by allowing more ventilation, raising the humidity, increasing light intensity or shading. As much as possible try to duplicate the natural growing conditions of the species or, in the case of hybrids, those species in the background of the hybrid. However, it is not wise to alter your environment dramatically to suit a plant- it is better to place the plant where it belongs and will thrive best naturally.


For example, plants of the hybrid genus Odontioda (Cochlioda x Odontoglossum) are cool-growing as are both parent genera. The same is true for Odontonia (Odontoglossum x Miltonia (actually Miltoniopsis)), Vuylstekeara (Miltonia x Cochlioda x Odontoglossum), and a few others. By contrast, hybrid genera such as Brassidium (Brassia x Oncidium), Miltassia (Miltonia x Brassia), Odontocidium (Odontoglossum x Oncidium), and others adapt well to intermediate conditions, defined below under Temperature. Some hybridists have brought the showy, cool-growing orchids down to us from the upper elevations to warmer climates by creating warmth tolerant masdevallias, cymbidiums, and odontoglossums...

But wait! What are all these orchid names. I thought that all orchids are these beautiful flowers that one can see in the department stores everywhere – Phalaenopsis?! There are many other orchid species and hybrids besides the moth orchid and key for success is first to find which one we are dealing with. For a beginner to identify an orchid looking at pictures is best tool and in this case internet could be helpful.

For how to grow Phalaenopsis For how to grow Cattleya For how to grow Cymbidium For how to grow Odontoglossum How to care about Dendrobium For how to grow Oncidium For how to grow Paphiopedilum For how to grow Vanda

To find most common orchids in cultivation and specific growing directions click here

The second principle in orchid growing applies when your plants are already in place in your home or glass house and you are responsible for their welfare. Some experienced growers argue that orchids thrive on being neglect. On the other hand, novices are prone to love their plants to death by over watering. The Golden  Mean between these two extremes is to observe. Inspect your plants regularly, not only for the first symptoms of leaf -spotting fungi or the footprints of a scale insect, but for signs  of improper culture - yellowing or loss of leaves, failure to flower, gradual decline. If a plant is clearly not doing well, don’t  wait to get better by itself, experiment with the variables even if this is going to speed up its demise. It is wrong to believe that plant will adapt to your conditions – the only thing that a plant is going to adapt to is the light direction.   


  Basics   Light   Watering   Fertilizing   Humidity    Air circulation  Potting  History  Back to top

Light

Without light for photosynthesis most plants will not survive long.
If beginners make any mistake at all in judging the amount of light needed, it is in underestimation. A common scenario in the demise of many house plants begins with the plant finding its new home in the bathroom or a dim bedroom. Although the plant brightens the environment for a while, soon the leaves begin to yellow and sag. Misdiagnosing the problem, the owner thinks that the plant needs water and gives it a good drenching. Without sufficient light for photosynthesis, the plant simply cannot use the water. As a result the potting medium remains wet, the roots rot, and soon only compost and a label remain.
 

Orchids are no exception to this scenario. To prevent it, buy only those plants that will adapt to the light conditions of your growing area whether it is a window sill, fluorescent light bench or a greenhouse. Depending on whether species in nature grow in the dim light of the forest floor among the leaf litter or high in the canopy of cloud forests, the amount of light needed for maintenance and flowering varies somewhat. Phalaenopsis and mottled leaved paphiopedilums such as P. callosum or its famous hybrid, P. Maudiae, will accept low light situations in the home, such as on window sills or trays under fluorescent lights. At the other extreme are the terete leaved vandas, which require full sun for flowering. Most orchids fall somewhere in the middle, between 2,000 and 3,000 foot-candles of light. If you do not have a light meter, think of it this way: depending on your latitude, full sun on a summer day will likely produce between 10,000 and 12,000 foot-candles. Once the light travels through glass its intensity drops by more than half. Among the different exposures available to windowsill growers in the Northern Hemisphere, the southern exposure is best because of its relatively uniform brightness throughout the day. The second-best exposure is the eastern one, which receives a few hours of strong morning sun. West facing windows tend to heat up too quickly and can seriously burn leaves, while northern exposures are generally too dim to be effective for flowering. The best exposure for growing orchids in the Southern Hemisphere is of course the northern one. Sun rooms or sun porches are excellent growing areas provided that all other climatic requirements are met.

A clear choice for those in cold climates are fluorescent light tubes, from the very simple cool white to warm white types to full spectrum lights and combinations thereof. The most convenient length for fixtures and tubes is 48 inches. Fixtures holding four tubes should be as close as possible to the plants without touching or burning the leaves. Some growers maintain the same day-night cycle (e.g. sixteen hours on, eight hours off) throughout the year with automatic timers, while others vary the "day length" of their setup according to the seasons, longer in summer and shorter in winter. Experimentation under your conditions is the best approach. Well grown plants generally have yellow green leaves. Though they look rich and healthy, dark green leaves usually indicate that more light is needed, especially for flowering. Move the plant to a brighter location in the home or glass house or, if it is under fluorescent lights, move it closer to the tubes and/or closer to the center of the tubes where intensity is highest, but do so gradually to prevent burning the leaves. If the leaves are bleached or yellow, the probable cause is excessive light intensity; move the plant to a dimmer location in the home or under lights, or increase shading in the greenhouse.
Temperature as we have seen. different orchid species grow from sea level (where there may be little variations in temperature over the course a day in the tropics) to 3000 meters above sea level (where there may be as much as a 15 C difference between the daytime high and overnight low temperature).
It seems intuitive that plants from one extreme will not succeed in the climate of the other extreme. As a result, orchid species and hybrids are customarily categorized as warm growing (minimum night temperature of 18 - 21C), intermediate (minimum of 13 - 18 C and cool-growing (10 - 13 C). Throughout this volume the temperature requirements of species are given to help you decide which are most suitable to your growing conditions. Remember also that a differential of about 10C is necessary for most orchids to flower. In the home this can be achieved by opening a window at night or by setting the thermostat down.

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Watering

Of all the basics to master, watering is the most difficult because so many other factors interact to affect its frequency: relative humidity, type of potting medium and pot, light intensity, temperature, air circulation. in addition, many orchids such as catasetums have a dormant or "resting period" in their annual cycle when they receive little or no water. In general, water only when the plants are in active growth, usually beginning in spring when new roots and shoots are initiated. Then reduce watering after flowering. However, orchids without pseudobulbs such as Phalaenopsis, Paphiopedilum and Masdevallia should not be allowed to dry out substantially.

The best way to judge if a plant needs water is to feel just below the surface of the potting medium; if it's moist, wait. Frequency of watering should increase with higher light intensities and temperatures, increased air circulation, lower relative humidity, use of clay pots with good drainage and an open potting medium. The amount of water given on each occasion should be enough to run out amply through the drainage holes in the pot or the bottom of the mount or basket. The goal is to flush out any dissolved salts that have accumulated in the medium so that they do not bum the roots.

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Fertilizing

Certain macro elements - nitrogen, phosphorus, and potassium - are necessary for plant growth, metabolism, and reproduction. Fertilizers are sold under different formulations depending on the relative concentrations of these three elements. Balanced, fertilizers, those with equal proportions of the three and sold under such formulations as 20-20-20 or 10 are recommended for tree-fern fiber, osmunda, sphagnum, and inert potting media such as gravel, lava rock, rockwool, etc. Higher concentrations of nitrogen in formulations such as 30-10-10 are frequently sold for plants potted in fir bark, while other products such as 10-30-20 have higher proportions of phosphorus to promote better flowering. As with watering, some general rules apply. Fertilize only when the plants are in active growth. it is advisable to water plants before fertilizing them so that the fertilizer salts are absorbed more readily by the roots and do not burn them. Another way to prevent this is to fertilize with only half the concentration recommended by the manufacturer (e.g. if the directions call for one teaspoon per gallon or four liters, then use only half a teaspoon). it is far more effective to fertilize at half-strength with every watering than to shock the plant with full-strength fertilizer every so often.

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Humidity

Relative humidity in the growing area, which can be measured by a simple instrument called a hygrometer, should be above 50 per cent and ideally 70 per cent. There are a number of ways to raise humidity if necessary. Syringing the plants with a fine mist is the most obvious method but effective only for a few minutes. Be sure that plant surfaces are dry by nightfall to discourage the growth of bacteria and fungi. One very useful technique is to set the plants a few centimeters above water on gravel-filled trays; the water level should be below the top of the gravel layer so that the bottom of the pot is never in direct contact with water. Grouping plants also will raise the humidity in their immediate area. If all else fails, room humidifiers are widely available and effective
 

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Air Circulation

Orchids in nature are constantly bathed in breezes and even gusts. Fresh, gently moving air in the home environment benefits plants as well as their owners. Ceiling fans, air-conditioning vents, small fans - all are helpful in preventing stagnant air that favors diseases and in ensuring uniform temperatures throughout the growing area. Be sure, though, that air is not blowing directly on any plants.

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Potting and Potting media

There are several ways to keep different orchids in captivity: pots, slabs of cork or tree-fern, baskets of sphagnum, natural mounts of branches or twigs. Which one of these is best is determined by the growth habit and cultural needs of the species in question. For example, stanhopeas have pendent inflorescences that penetrate the potting medium and emerge below. Potting these in a basket lined with sphagnum moss therefore allows the flowers to be displayed to their full advantage. Vandas and ascocentrums (as well as their hybrid genus, Ascocenda) also thrive in baskets, but with ,,came bark or charcoal loosely packed around the roots. Those species that prefer to dry out thoroughly between waterings are best suited to cork or tree-fern slabs, while those that prefer moister conditions should go into clay or plastic pots. Plastic pots "breathe" less than clay and therefore retain moisture longer, a factor to consider when watering.

When potting an orchid, the diameter at the top should be no larger than to allow one or two years of growth. Miniature orchids, for example, are very happy in pots five to eight centimeters wide, while standard cattleyas and cymbidiums with five or six growths require pots with much larger diameters. For sympodial orchids, there should be enough space between the youngest shoot and the rim of the pot to allow for two years of growth. Fill the pot about one-third full with stones or even Styrofoam pellets of the sort used as packing material. Add enough potting medium so that the rhizome of the plant will be only about one or two centimeters below the rim, then fill in around the plant with medium, pressing it down firmly in the process. larger plants may require a rhizome clip or a stake to immobilize them until new roots are initiated and they are well established. Never forget to insert a plant label in the medium, giving the name of the plant and date of repotting Monopodial orchids are potted similarly but positioned in the center of the pot instead of to one edge; remember that these types have no rhizome and grow vertically instead of horizontally. The lowest leaf should lie just above the potting medium. When vandas ascocentrums, and ascocendas outgrow their slotted baskets, the procedure is different. Rather than try to detach the aerial roots from the basket and risk setting the plant back, soak the plant (basket and all) in a bucket of water for a few minutes to make the roots more pliable. Then set the basket within a slightly larger basket, wrap the roots around and set them inside the basket also. Wire the baskets together, add a wire hanger, and attach a new label as above.

Sympodial orchids are very readily propagated asexually by division of the rhizome. When reporting think about whether or not the plant should be divided. Using a new razor blade or a knife or pruning shears sterilized over a flame, cut the rhizome so that each division has three or more growths and preferably at least one actively growing lead. Remove withered pseudobulbs and leaves and snip off dead, brown, and mushy roots. Healthy roots are firm and white with well-defined root-tips. Back bulbs may have dormant buds, so pot them up separately. Obviously, without a rhizome monopodial plants cannot be divided in this way. However, many such as Phalaenopsis species and hybrids produce offshoots called "keikis" at nodes along the inflorescence axis. When the roots of the keikis is are a few centimeters long, the plantlets can be potted up in the same way as the parent plants. Older plants that become top-heavy may be severed. the top half with its set of aerial roots moved to a different pot or basket. A wide array of epiphytes, needing more air around the roots and drier conditions than a pot allows, prefer to be mounted on slabs of cork bark or tree-fern fiber. Simply place the plant on the mount cushioned by a small pad of osmunda or sphagnum moss. Wire the plant through the slab to the back of the mount and tighten. Some growers use staples instead of wire. Attach a hanger and plant label to the top and hang the newly mounted plant in a relatively shady place until it is established on the slab.

Potting Media

Years ago the potting medium of choice for epiphytes was osmunda fiber, the roots of the Osmunda fern. When the supply of osmunda failed to meet the demand, however, other media were sought, both organic and inorganic. Today the two most common are tree-fern fiber and fir bark, used in various combinations with perlite or pumice, charcoal, redwood bark, sphagnum moss, lava rock, and cork. Sizes of tree-fern, bark, and charcoal are graded as coarse (for vandas and large sympodials), fine (for seedlings and miniature plants with delicate roots), and medium (for everything else). The potting medium you choose should always be free-draining so that water does not accumulate around the roots mix for  terrestrials such as Orchis and Ophrys usually contains various proportions of  loam, coarse sand and leaf mold with traces of  blood and bone meal.
 
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History

 

cattleya_rex_drawing.jpg (30349 bytes)

We will never know who first placed the orchid in captivity. The reason may have been medicinal or purely aesthetic.
We do know that the Chinese word for orchid, lan, appears in herbals 4,000 years ago. Confucius (551-479 BC) commented on the orchid's fragrance. By the third century A.D., references to what we now know as Cymbidium ensifolium and Dendrobium moniliforme appeared in Chinese botanical manuscripts (Reinikka,  1972).

In the Western world the Father of Botany, Theophrastus, mentioned Orchis in his Enquiry into Plants around 300 B.C. Thereafter European orchids appeared in the early herbals, up until the seventeenth century.

Vanilla even appeared in the Badianus  Manuscript, the sixteenth-century Aztec herbal.

Some of the first orchids in cultivation in the West, brought back from all parts of the world, were maintained at the Royal Botanic Gardens, Kew, England, in the mid-1700s It was not until plants of Cattleya labiata flowered for Mr. William Cattley  in 1818, however, that orchids began to be cultivated on a large scale. Pseudobulbs of this orchid had been sent from the Organ Mountains near Rio de Janeiro, Brazil, as packing material for other ornamental plants, and Cattley set the plant in his glass house or "stove." When it flowered, he showed it to the famous botanist and orchid taxonomist, John Lindley. Lindley named the genus in his honor and the species for the magnificent labellum. More collectors were then commissioned to find additional plants and species. Unfortunately, the first attempts at growing orchids in the stoves were tragic failures. Because many of the orchids arriving on British shores were from the warm coastal lowlands, it was assumed that all tropical orchids required the hot and humid climate of rain forests, when in fact many were being collected from the inland cloud forests hundreds of meters in elevation. As a result orchids died by the thousands, prompting the orchid taxonomist and Director of Kew Gardens, Joseph Dalton Hooker, to comment that England had become "the graveyard of tropical orchids." On the advice of John Lindley, who sought climatic information about habitats from collectors, growers such as Joseph Paxton opened up the stoves to allow cooler temperatures and greater air circulation and thereby more closely approximate cloud forest conditions.
By the end of the nineteenth century, orchid growing was a less risky enterprise and a popular Victorian pastime for those who could afford the prices of wild collected plants. Major firms such as James Veitch & Sons and Sander's maintained a cadre of professional collectors living abroad and sending huge consignments of orchids, sometimes thousands at a time, back to England on a regular basis to meet the demand. just after the turn of the twentieth century, orchids seemed to fall out of fashion in favor of other plants.
The costs of collecting and shipping skyrocketed, as did the costs associated with glass house maintenance. One by one the professional collectors working in the tropics - Wallis, Arnold, Falkenberg, Degance,  Klaboch, Endres were  killed by natives or thieves, died from such diseases as dysentery, malaria, and yellow fever, disappeared in the jungles, or grew too old to travel and died penniless (Reinikka, 1972). Many of Frederick Sander’s collectors wrote bitterly to him, complaining about his failure to send letters of credit to firms abroad on their behalf so that they could buy provisions and, more importantly, orchids (letters to F. Sander, Kew). Most of those who lived resigned from his employ.
Orchid growing as a hobby was rejuvenated by the work of Bernard and Burgeff on symbiotic germination of orchid seeds and by the reports from Knudson on asymbiotic germination. Seedlings could now be produced quickly and cheaply. Prices for orchids plummeted, just as an entire industry built around orchid hybridization was finding itself. Following the Second World War, several established firms in England, France, Hawaii and the United States dominated the international orchid wide.
The industry received another boost with the discovery in the 1960s that the excised growing point of an orchid, the apical meristem, would proliferate when agitated in nutrient solutions; one plant could produce hundreds of nearly identical copies of itself.
Today selected clones of both species and hybrids are reproduced by this laboratory process called meristeming or mericloning. Propagation by meristeming and flasking (raising seedlings on nutrient agar in a glass flask) have made it possible to see orchids selling for a few dollars and entering the pot-plant market once monopolized by African violets, spathiphyllums, and Boston ferns Orchids have come of age - from wild collected innocents exploited by a few for the privileged few, to artificially propagated plants raised en masse for the general public.

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