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The first thing I learned about orchids is that, contrary to popular opinion, not all of them grow in the warm, moist, rainforest conditions that exist in Latin America or Southeast Asia, where many of them originate. Some grow at higher elevations, under constant cloud cover, and thus require cooler temperatures.
Rainforest orchids are naturally hydroponic, growing in moss on the sides of trees or rocks, and getting their nourishment from the constant rain pouring over their roots, as well as from the decomposing debris of the forest. They are kind to their hosts; they never take nourishment from the tree itself, and thus are not parasitic.
Other orchids grow in moderate climates such as that found in most of Europe. In order to grow orchids year round, most growers, including myself, use hydroponic methods, either in a greenhouse, or in a room set aside for this purpose.
Cool-growing orchids require nighttime temperatures of 50° to 55° F (10° to 13° C), while their daytime preference is 60° to 75° F (16° to 24° C). The beauty of hydroponics is that you can control the temperature and humidity of the growing space. This cool-growing group includes cymbidiums, odontoglossums, masdevallias, and many paphiopedilums.
Intermediate-growing orchids include the most popular varieties such as cattleyas, dendrobiums, many oncidiums, some paphiopedilums, and a large number of the co-called botanical or species orchids.
These thrive at 55° to 60° F at night (13° to 16° C), while preferring 65° to 80° F (18° to 27° C) during daylight hours. If you have a cooling unit in the summer and a heating unit in the winter, you can easily set these temperatures on your automatic timer.
Warm-growing orchids don’t appreciate their nighttime temperature any lower than 60° to 65° F (16° to 18° C) while in the daytime they prefer 70° to 85° F (21° to 27° C). These include vandas, phalaenopsis, and some tropical paphiopedilums.
If temperatures exceed these recommendations for more than a brief period, the orchids will suffer. If the sunlight or artificial light is too bright, they can get sunburned—bleached areas that will soon turn black or brown.
High heat and too strong a light will also cause plants to lose moisture through their leaves. Even if they don’t look sunburned or otherwise stressed, excessive temperatures definitely have an adverse effect on the plants. They will turn more and more yellowish and will stop growing or refuse to bloom.
Although in the wild most orchids grow in humid environments, indoors they can make do with as low as 40 percent humidity. That being said, freshly potted plants should be kept in 100 percent humidity until they grow new roots. Most varieties are happiest at 50 to 80 percent humidity.
Since I learned early on never to let the roots of my plants dry out completely, I use a double pot system, where the inner mesh pot holds the growing medium (I’ll get to that later) and the outer pot the nutrition solution in water.
I put pebbles on the bottom of the outer pot and allow an inch or two of reservoir liquid in the pots at all times. Through capillary action known as “wicking,” the roots absorb this life-giving solution.
It is important not to let the roots stand in stagnant water, since they do rot. With safety holes on the outer pot to insure drainage of excess solution, it is almost impossible to overwater.
Some growers make the mistake of misting the plants constantly, thus giving rise to the onset of mold or mildew or viral diseases.
Using a process known as integrated pest management (IPM), I am able to minimize the danger of pest infestation. Common sense sanitary measures come into play here.
You can bring in diseases or pests from the outside (especially if you allow children or dogs into your grow space), so it’s important to wash your clothing and hair often and even clean the bottom of your shoes as you enter the grow space. Clean all plant materials and debris immediately, and get rid of weeds near the entryway.
The parasites that like to munch on orchids include red spider mites, aphids, mealybugs, scales, and snails. Orchids are also prone to viral infections and black rot, caused by several different fungi that thrive in low temperatures and high humidity.
Washing the plant with a soapy solution can be as effective as and is safer than using a chemically produced product, since many parasites develop a resistance to chemicals over time.
You can also use safe, non-toxic formulas made by the Advanced Nutrients company. These include Genius Oil, Bug Away, Barricade and Scorpion Juice. These formulas go beyond a topical approach to protecting plants. They provide systemic protection that armors plants from the inside out.
Scorpion Juice creates an acquired systemic resistance in the plant that helps resist insects and pathogens, like powdery mildew.
Barricade contains potassium silicate that increases cell wall stability and insures vigorous internal functions.
Light and air are absolutely essential to healthy, productive orchid plants. In commercial growing operations, High Intensity Discharge (HID) lights are often used, either to supplement daylight in a greenhouse, or to provide the entire spectrum of light indoors, which is necessary for photosynthesis.
Orchids should not receive light for more than 14 hours a day. More than that will prevent them from blooming. My experience has also shown that too little light also harms orchids, so it has to be a fine balance.
I have a 12’ x 18’ grow room, which takes six 400 Watt Metal Halide lights, each covering a 6’ x 6’ section, or 36 square feet. My walls are covered with white plastic sheets to reflect light and to produce a greenhouse effect. Fans suspended from the ceiling move air constantly between the plants and a CO2 generator makes sure that enough carbon dioxide is in the air for optimum photosynthesis.
The regular Metal Halide bulbs produce light at the blue end of the spectrum, which is ideal for vegetative growth. Once the plants start to bloom, they require light at the red end of the spectrum, which I provide by changing to High Pressure Sodium Conversion lamps, using the same ballasts.
My intense lighting is not beneficial to all species of orchid. The ones that need more shade are placed on the periphery and some are actually shaded by shadecloth. However, most of the varieties I grow need a lot of light.
There are two basic types of orchids—monopodial or single stem, and sympodial—much more common—which has a main axis, but it grows mostly horizontally, using several swollen shoots called pseudobulbs. These serve as a reservoir for water and nutrients for the plant. The sympodial orchid develops new shoots once a year at the base of the pseudobulb.
The much-admired orchid flower consists of a dorsal sepal and twin petals embracing the staminodium and lip, with a lateral sepal on the bottom. The many forms and colours that make orchids so unique can be explained as being adaptations designed to attract specific pollinating insects that allow flowers to propagate in the wild.
It seems that the architecture of orchids is predetermined by the pollinator they are trying to attract, while some species have acquired defensive weapons and behaviours to ward off undesirable pollinating insects.
Some orchid shapes mimic the shapes of bees, wasps, or spiders to scare away unwanted pollinators. Orchids that do not welcome bees as pollinators actually secrete bee-specific sedatives, which disarm invading bees who try to pollinate the flowers. Other orchids can actually move their flowers in such a way that the unwanted pollinators are scared off.
Some orchids, which do not want to be pollinated by wasps, have evolved the ability to close their petals when they sense a wasp nearby, or to emit the pheromone scent of a mating-receptive female wasp. Other females are repelled, while the males try to mate with the flower, rather than pollinate its bloom.
So how do you pollinate orchids when you don’t want to let insects into your grow room? The answer is hand pollination. It’s a highly labour intensive method, as you remove the pollinia from the male of the species and gently place the pollinia onto the sticky stigma surface of the female flower.
In larger greenhouse operations, you might want to let the bees in, but you have to make sure you have orchid species that accept bee pollination. Sometimes the ordinary housefly can pollinate a plant.
The propagation of orchids from seeds is very difficult. That is why some growers prefer stem propagation, which also requires a whole series of steps. I’ll discuss these steps in a future article.
Unfortunately, orchids are not the kind of plant where you can take a cutting, stick it into water, and wait until roots appear.
Universities are experimenting with tissue culture. This involves taking a group of cells from the mother plant and then dividing them. Each cell can give birth to an identical plant, so one plant can be the source of millions of look-alike plants. Cellular propagation looks very promising for orchids.
Getting back to the question of the potting mixture. Many orchids are potted in fir bark, which is inexpensive, comes in a variety of sizes, and breaks down slowly. Chunks of coconut fibre are sometimes used, and they retain water longer than bark. You can use a coconut fiber root media called coco coir.
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Some growers prefer lava rock or gravel, which do not break down at all and they afford excellent aeration around roots.
Use a quartz-based gravel, rather than a marble-based one. Perlite or sponge rock is seldom used alone, but it is a key ingredient in many mixtures, as are vermiculite and peat moss. Horticultural grade vermiculite is recommended. Perlite, vermiculite, spongerock (coarse perlite), fired clay pellets, or gravel are my choice of grow medium.
Sphagnum moss is used by many growers, especially for plants intended for sale. Moss is lightweight, when shipping is a consideration.
I sometimes use potting mixes, depending on the species being grown. For instance, for the lady slipper orchid (phapiopedilum) you can use:
3 parts fern root
3 parts fibrous moss
3 parts baked clay pellets
1 part charcoal chunks (3-8mm in diameter)
add a teaspoon (2 g) of calcium carbonate to each 2 litres of substrate
For terrestrial orchids, replace the fibrous moss with sandy loam or peat moss.
Orchid growers used to argue about whether or not orchids needed to be fertilized. With time, the answer came—orchids grow much better when the plant receives fertilizer. A proper feeding schedule that takes the growing requirements into consideration produces richer-blooming orchids. The same amount of fertilizer should not be given throughout the year. Grow and rest periods should be observed, and feeding should be suspended during the latter.
Nitrogen (N) supports the growth of the plant, phosphorus (P) influences the development of flowers, and potassium (K) strengthens and supports the developing flowers.
Advanced Nutrients VitaBoost Pro, Organic B, SensiZym, Emerald Shaman and Iguana Juice have proven to be excellent in feeding my orchids.
I also found that Advanced Nutrients B52 Fertilizer Booster, with essential B vitamins and hormones, increases the plant metabolism of my orchids and strengthens their immune systems. Another one of their products, Bloom Booster, has helped to insure not only plentiful flowers, but also high quality blooms on my orchid plants.
Given the rising popularity of orchids throughout the world, it can safely be said that if you follow the guidelines set forth in this article, you will be able to grow marketable blooms of these highly-prized flowers.
There are over 25,000 species of orchids, as well as 65,000 to 100,000 hybrids, depending on what source you believe. A thousand new hybrids are created by imaginative growers each year.
Orchids are very popular in countries like the U.S. These exotic plants can range in cost from $15 to $4,000.
U.S. imports of live orchid plants increased from 564,000 in 1999 to 1,507,000 in 2003. The value of these imports rose from $11 million to $27 million, in the same period. Since orchids in the tropics grow “hydroponically” by nature, this ornamental should be among the top choices for the fledgling horticulturalist.
In the rain forests of Latin America, orchids grow in moss on the sides of trees or even on rocks, with their roots being supplied with moisture by the constant rain.
Surprisingly, after Taiwan and Thailand, Canada is the third largest exporter of live orchid plants to the U.S. (267,000 in 2003).
It seems that the hydroponic gardeners north of the 49th parallel have already decided that orchids are good business.
The value of orchid sales in Hawaii’s orchid industry went from $15.5 million in the late 1990’s to $22.8 million in 2004. Potted orchids provided the lion’s share of these sales ($18.4 million). Orchid breeding, propagation, production, research and marketing keep the 150 orchid growers in Hawaii quite busy, indeed.
The University of Maryland Easter Shore (UMES) has entered into a long-term partnership with U.S. Orchid, the American arm of Jet Green Horticulture in Beijing, China. The hydroponics greenhouse facility at UMES covers 2.5 acres and cost $4 million U.S. Purple, white, pink, and yellow orchids are blooming as part of the $2 million deal to import plants from China, in lots of 200,000 each.
Not only is UMES positioning itself to become the major supplier of orchids on the U.S. east coast, but also to conduct research in developing new hybrids and perfecting the cultivation of this delicate, yet prolific cultivar.
There are 25,000 different species of orchids, plus another 60,000 hybrids that have been produced by growers with imaginations. A thousand new varieties are developed each year.
If you’re thinking of setting up your very own orchid growing operation, do extensive research as to the most popular varieties, as well as the most economical to produce.
Most orchids are grown for their beauty—others, such as the Vanilla Orchid, are used to extract the vanilla flavour for pastry chefs around the world.
If you live in northern climates, where sunlight is not readily available in the wintertime, your hydroponic greenhouse must have additional lighting. A 400 Watt metal halide lamp is ideal for illuminating a 6’x6’ area. Metal halide provides the blue in the spectrum necessary for the initial growth of the plant (substitute sunlight). Then, when you approach the maturing of the flowers, you can put in a high pressure sodium bulb that provides the warm spectrum of light necessary for flower production.
To maximize humidity, you might cover the walls of the grow room with white plastic sheets, which serve a double purpose—to insure a greenhouse effect as well as to reflect more light onto the plants.
According to an expert grower, the key to successful orchid culture is moisture, nutrition, and air. Fresh air, good air circulation, is essential for orchids under lights. The high humidity required for orchids is a breeding ground for fungus and viruses. Every cubic feet of air in the grow room should be changed every 2.5 minutes. Depending on room size, large fans suspended from the ceiling will move air vertically onto the plants, while side fans will keep it circulating throughout the room. The use of Advanced Nutrients hydroponic plant food will insure optimum nutrition going to the lovely flowers, whether you use perlite, vermiculite, spongerock (coarse perlite), fired clay pellets, or gravel as your grow medium.
A double pot system is the most popular, with the inner mesh pot holding the plant in the grow medium, while the outer solid pot holds the nutrient solution in water. The outer pot usually has a water gauge, so overwatering can be avoided. Let the roots nearly dry out between waterings.
Sometimes the outer pot also has a drainage hole drilled an inch from the bottom, to siphon off excess water, but also to retain a “reservoir” at the bottom to keep the roots minimally moist. The roots “wick” just fine—they suck up the water-nutrient mixture evenly.
Experienced growers use sphagnum moss to hold the orchids destined for sale (it’s lighter during shipping), but a more durable grow medium for plants they keep for themselves.
Orchids that originate in Africa are usually white, while the Asian ones are multicoloured.
The University of Maryland has applied for a federal grant to establish a tissue culture laboratory on campus. This involves taking a small, undifferentiated group of cells from a mother plant and then dividing them—each cell giving birth to an identical plant, so one plant can be the origin of millions of look-alike plants.
It seems that what starts as a hobby can turn into a business. If you use high quality plant products such as those made by Advanced Nutrients, and if you follow good gardening practices, you might soon be growing orchids that other people are willing to pay you for.
All material is copyrighted, 2006 by Advanced Nutrients and can’t be copied, excerpted or otherwise used without the express, written permission of Advanced Nutrients
