The orchid grower's task, and it is no easy one, is to set in motion the complicated growth processes of the orchid plant, and, through maintenance of proper balance, insure continuation of that process and orchid care.
Using the energy provided by light, the green leaf chlorophyll transforms the carbon dioxide from the air and the mineral salts from moisture into sugar and other carbohydrates.
These energy carbohydrates are stored until needed either for rebuilding plant tissue or for flowering. The pseudobulbs of some types, the large leathery leaves of others, and the slender grass-like leaves of orchids lacking pseudobulbs are the storage reservoirs.
The cycle will continue only if the grower devotes the utmost attention to the special requirements of the orchid. The reward for his devotion comes when the brilliant bloom and beauty of the tropics is reproduced in the greenhouse with orchid care.
No hard and fast rules can be set down for the beginner to follow when it comes to orchid growth and orchid care. It has been said that each grower in his own greenhouse, within limitations established by the plants, is a law unto herself.
The amount of each element in the light-heat-moisture-air formula will vary according to season, experience, and variety. One of the things that make the growing of orchids unique and stimulating is the spirited controversy that arises over every aspect of culture.
One of the many points on which there is no incontroversial procedure is the matter of how much light should be admitted. It must be decided whether to grow the plants 'soft' or 'hard,' to use the parlance of experienced growers.
The amateur must make her own choice. To grow 'soft' means to shade the plants from the sun so that the leaves remain a beautiful dark green. There can be no doubt that this method produces the most beautiful plants, but the quality of bloom is a question that cannot be answered so definitely.
In 'soft' conditions care must be exercised not to shade to the point where flower growth will be hindered.
To grow 'hard' means to allow so much light that the leaves have decided overtones of yellow. This method, while marring the appearance of the plant, is said by its proponents to give increased bloom. Too much light must be avoided, since it will burn the plant and growth will be interrupted.
Dry, yellow flower sheaths will at times result from such sunburn, and incipient buds will become steamy and subject to destruction by wet rot. Cutting off the very top of such a sheath with a sharp knife will allow air to reach the bud and may save it.
The claim that growing orchids 'hard' increases flower growth appears logical if the conditions under which orchids grow in their natural state are considered: the natural environment is 'hard.' It must be remembered, however, that nature controls sunlight in a way difficult to approximate in the greenhouse.
Even in those areas where certain varieties grow in so-called 'full sun/ it will be found that drifting clouds give a protection that is absent under intensely directed light in the greenhouse.
Once the amateur has made the choice between 'soft' and 'hard' methods, the subsequent treatment must be consistent when it comes to orchid care. If much sun is provided, more moisture and air will be required. If the plants are grown with minimum sun they will require less moisture, but an increase in ventilation may be needed to keep the air sweet.
Too great an increase in heat during the winter is a common error of orchid growers. Plants store up energy during the daylight hours and give off or transpire energy at night. Increase in night heat increases transpiration.
Shorter periods of daylight lessen the manufacture of energy. If the plant loses more energy at night than it is able to store during the day, obviously it will suffer. Orchids are very susceptible to shock of any kind, and they take considerable time to recover—if they ever do.
This danger must be borne in mind regarding sunburn, chilling, or energy deficit in orchid care.
There is the further difficulty of each species' having its own light requirements. Quick reference to conditions in the native homes of the species that the amateur is likely to acquire will illustrate the point.
Cattleyas, native to Central and South America, are found hanging on trees in the tropical rain forests. The burning sun of midday is usually kept off the plant by foliage directly overhead.
The grower, guided by this knowledge, lets Cattleyas be exposed to the sun, but provides shade in summer during the warmest part of the day, for sunburn must be avoided when caring for orchids.
The increased exposure to sun necessitates a corresponding increase in humidity to prevent the pseudobulbs from shriveling.
Laelias, showy natives of Mexico and Central America, are found growing on rocks in the open sun. They are closely related to Cattleyas, but require larger amounts of both light and air.
The grower should find a place for them in the sun, right up under the glass. Sudden temperature changes should be avoided.
Among the sun-worshipers are the Vandas, natives of India, the Philippines, and some Pacific islands. They will not thrive without adequate sun, and they must have corresponding amounts of heat and water. Care must be exercised to keep water from remaining in the growing crown.
The evergreen Dendrobiums, native to the Indian Islands, and Oncidiums, from Central and South America, are also sun-worshipers. Phalaenopsis, the lovely white 'bride's orchids' from the Philippines and the Eastern Archipelago, respond well to sun, but must not be overexposed.
A warm, moist atmosphere, with plenty of air, is best for this species. Zygopetalums, found in Brazil, Venezuela, and the Guianas, require moderate exposure to sun.
As a rule orchids from mountainous regions or from the temperate zone need protection from direct sun. Cymbidiums, natives of the Himalayas, require controlled sun and cool conditions with abundant air.
These spray orchids, with their Joseph's-coat range of colors from pink, yellow, green, and brown to the rare pure white, are difficult to grow under glass because they like their 'heads hot and feet cold'; but with careful observation a proper balance can be worked out.