Growing Orchids

Orchid Cultural Requirements
Growing Medium
There are many different types of orchid potting medium used in orchid culture. The overall consideration is to provide structural support for the orchid roots, but also to provide lots of air spaces between medium particles. Many orchid plants are grown in osmunda fiber. This fiber comes from the roots of the Osmunda fern that is native to Australia and the Pacific. The tough, wiry fibers break down very slowly and is an ideal potting medium. Fresh pine bark is also a popular medium but is usually mixed with other amendments before use. Both materials are sometimes mixed with peat and perlite or vermiculite. Some orchids are even grown in pebbles mixed with bark. Most orchid roots are adapted to being exposed to air and harsh conditions, but cannot tolerate being wet for more than a day or two.


Growing Orchids

Orchids grow slowly compared to houseplants. However, most orchids need to be repotted about once every two years. To pot an orchid, the pot is filled about two-thirds with orchid potting medium, then the plant is set in the pot with its roots spread out. The growing tip either centered (monopodials) or placed two fingers from the pot rim (sympodial). Then additional media is packed tightly around the plant to hold it in place. You should be able to turn the pot upside down without the orchid or medium falling out. Practice will insure successful repotting. When the plant outgrows the pot by extending the new shoots over the edge, usually about every two years, it is time to repot.


Growing Orchids

Light
The ideal place in the home for growing orchids is a bright window, free from drafts, where your plants receive indirect sunlight both morning and afternoon. (A south window is best.) In winter, give orchids all the light possible. Light intensity should be between 1500 and 2000 foot candles the equivalent to a bright south-facing window. With extra large windows or especially intense sunlight, the light may be adjusted downward by moving plants 18 to 36 inches from the window. Plants in the home require a greater light intensity because they receive light from only one direction, while in a greenhouse they receive light from many sides. Many orchids can be grown in a greenhouse or outdoors. All will require partial shade. Therefore, it is best to shade the section of the greenhouse you intend using or else grow them in an area that you have already shaded for foliage plants or African violets. Dendrobium Oncidium and Vanda will grow best in 20-30% of normal outdoor light, whereas Phalaenopsis-type orchids require only 10- 15 % of normal light.


Growing Orchids