University of Illinois Extension

 


Barbara Larson
Unit Educator, Horticulture
Boone and Winnebago Counties

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Growing Orchids

What plants easily grow indoors, require minimal care, and produce beautiful exotic flowers? The answer is orchids.

Orchids have been characterized as finicky plants that need greenhouses or other specialized care, but many orchids grow very successfully alongside other houseplants.

Many orchids require the same temperature range as houseplants. Daytime highs in the 70’s and nighttime lows of 55-65F will keep orchids and houseplants growing happily. Orchids (and other houseplants) next to windows on extremely cold nights may be cold damaged and should be moved away from windows.

A bright window with indirect sunlight all day is ideal. Generally 12 to 36 inches away from a south window is best. Many orchid hobbyists move their plants to shade locations outdoors for the summer. Orchids also grow and bloom well under artificial fluorescent lighting. Minimum light requirements, without supplementary daylight, are two 36-48 inch shoplights with regular forty-watt fluorescent bulbs hung six inches above the plants. Lights should be on at least 12 hours per day. However, flowering will be improved in plants receiving natural and artificial light versus artificial light alone.

Proper watering is critical to successful orchid culture. Overwatering will quickly kill most orchids. The thick fleshy roots of orchids require the good drainage provided by special soilless potting mixtures containing either fir bark or osmunda fern fibers. In general, water once a week. Orchids growing in clay pots may need more frequent watering. The potting mix should dry slightly between waterings. Add enough water each time to run out of the drainage holes in the bottom of the pot.

Orchids respond well to regular fertilization but are damaged or killed by too much fertilizer. Once a month, a water-soluble fertilizer should be applied as part of normal watering. Universities recommend either a complete 20-20-20 fertilizer or specialty 30-10-10 orchid fertilizer.

After blooming stops, watering and fertilizing should be reduced until new leaves appear.

Most homes, especially in winter, are too dry for orchids. The easiest way to increase humidity around the plants is to set the pots on pebbles with water in a tray or saucer. The evaporating water makes the air around the plants more humid. The pot should not sit in the water but be raised above the water level by the stones. Decorative rocks may be used for a more pleasing appearance. Orchids may also be misted with distilled water to raise humidity levels.

Beyond the basic cultural suggestions, the key to successfully growing orchids is matching the type of orchid to the conditions in the home. Beginners should buy flowering or mature sized plants because orchids take five to seven years to reach to bloom size.

Most orchid enthusiasts agree that the best orchid for novices is Phalaenopsis. Commonly called moth orchids for their lovely flowers, Phalaenopsis produce long sprays of flowers lasting at least six weeks. They adapt well to the typical temperature in homes (65F nights and 75F days) and the bright light near an east window. Phalaenopsis may be grown exclusively under artificial light.

Cattleyas are the quintessential corsage orchid. Often large and showy, the individual flowers last two to six weeks. Cattleya plants need twice as much light as Phalaenopsis. Indirect light in a south window and/or supplemental lighting is recommended. They also perform better in slightly lower temperatures of 60F at night and 70-75F during the day.

Dendrobium orchids are white, lavender, or a combination of the two colors. The long lasting flowers are borne in lengthy sprays. They grow best in conditions similar to cattleyas.

Epidendrums produce an abundance of small (1inch) flowers. Like Phalaenopsis, they are considered very easy to grow.

Oncidium orchids are called dancing girls because of their dainty yellow and brown or white and brown blooms. These tough plants flower reliably under most conditions.

The huge family of orchids contains 880 genera, 28,000 species, and over 300,000 registered cultivars worldwide. With so many choices, most people will be able to find an orchid that will thrive in their home.

More information on orchids is available from the American Orchid Society, Membership Services Dept., 6000 South Olive Ave., West Palm Beach, FL 33405-9974 or on the web at www.orchidweb.org.

April - May 2002: Viburnums: Shrubs with Four Season Interest | Discouraging Canada Geese | Yellowjacket Control—Now is the Best Time to Do It | Growing Orchids

Past Issues

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