Tips for Growing Orchids - Different species of orchids require different types of care. 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. Odontoglossums, aristocrats of South America, are normally found at heights of from 5,000 to 12,000 feet. They require cool, shaded conditions at all times and for this reason they are a little difficult to raise with other species. Mil-tonias are found at heights up to 8000 feet in Brazil, Costa Rica, and Colombia. They require shaded sunlight. Deciduous Dendro-biums, native to India and the Philippines, must be protected from the sun during the growing season.

Cypripediums, usually called lady's slippers, are found in many lands and in a great variety of climates. Consequently they like differing amounts of sun, but all must be protected from burning. Generally the mottled-leaved types require more shade and more heat.
The problem of the amount of heat is closely allied to the matter of light. Most climates in the temperate zone require artificial heat in the orchid house to supplement that provided by the sun. Automatic controls simplify the matter, but they do not take the place of brainwork. The beginner must watch his plants carefully, combining all his knowledge of orchids with solicitous observation and a strong admixture of green thumb. Experimenting with orchids is extremely precarious because their life cycle is so long, five to seven years from seed to bloom, and the cause of damage may have been forgotten in the six or eight months before it is evident.

The grower should vary heat conditions to balance other conditions of the house and plants. As in most native habitats, the temperature can be some degrees lower in winter than in summer. This is another point on which there is difference of opinion.

Some growers increase the heat a bit during the winter day, reducing it again at night to sustain balance.
As was pointed out in Chapter 3, the ideal set-up for growing the widely differing genera would be the three-house system. One house would be for orchids tolerating 45 to 48 degrees F. minimum night temperature in the winter—Cymbidiums, some Laelias and Cypripediums, and all Odontoglossums. The second house would be the 'intermediate' or 'Cattleya' house, requiring moderate sun and a heat of 58 to 65 degrees F. minimum night temperature in winter. Cattleyas, allied genera, and hybrids thrive in a house of this type. The third house would be the 'hothouse,' with a minimum night temperature in winter of 65 to 70 degrees F.

Tiny seedlings, Dendrobiums (although the deciduous type should be removed to a cooler house while resting), Cypri-pedium Maudiae, Phalaenopsis, and Vanda Sanderiana are among the types preferring conditions of this house.

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