Orchid Blooming Culture

Temperature

• The indoor temperature range for many homes is 65 to 75 degrees Fahrenheit. Orchids need a 10-degree difference between daytime and nighttime temperatures to store their energy for blooming. Cool-growing orchids such as cymbidiums need night temperatures of 55 degrees Fahrenheit and above, with daytimes at 75 degrees or below. Cattleya requires a low of 60 degrees Fahrenheit at night and a high of 75 during the day in order to develop blooms. Warm-growing orchids such as phalaenopis thrive with a nighttime low of 65 degrees Fahrenheit and daytime high of 85 degrees Fahrenheit.

Light

• Orchids create blooms by using light as food. They have light green leaves when they are receiving the right amount of light. Bluish-green or dark green, soft leaves indicate the plant is not getting enough light. Yellow bleached foliage or darker red mottled leaves indicate too much light. Even orchids that tolerate direct sunlight prefer it to be dappled through a high canopy of tree foliage. Cymbidiums grow well under a large tree that receives morning sun. They are able to tolerate higher temperatures and more sun when air circulates to cool their leaves. Choose the windowsill with the brightest light to get the best blooms on indoor orchids.

Humidity

• The natural growing environment of orchids is the humid tropics. A tray of pebbles underneath potted orchid plants successfully produces a humid environment at home. Heat from the pebbles warms the surrounding water and creates a steamy environment. Spraying orchid plants frequently also creates humidity for them. Mist or lightly spray outdoor plants to maintain even humidity, especially during warm summer months. When heat builds up indoors, air circulation is increased by directing a fan just above the orchid leaves.

Fertilize

• Many orchids in the wild get their nutrients from rain and wind-blown debris settling on their exposed roots. They grow in peat moss or fir bark in home gardens, which do not provide nutrients. Orchids must rely on a regular schedule of fertilizer to create blooming flowers. They prefer a very weak solution of organic fertilizer or fertilizer specially formulated to encourage orchid blooms. Over-fertilizing burns roots and leaves and creates a buildup of salts that weaken the plant. Orchids thrive and bloom when fed weakly every week during spring and summer, using one-fourth the recommended strength of plant food.