Choosing a Plant
There are more varieties of orchids than of any other family of flowering plants – more than 20,000 varieties! The unanimous choice for the first-time orchid grower is Phalaenopsis, also called the “moth orchid.” There are about 50 varieties of Phalaenopsis, all of which can be grown successfully in typical home conditions.
You can find moth orchids at garden centers or florist shops or from mail-order companies. Look for strong, shiny leaves without blemishes and clear, bright colors on the flowers. Don’t be surprised to see the roots creeping over the surface of the potting medium – Phalaenopsis roots like exposure to the open air – but do make sure that any roots you see look plump and healthy.
Pots and Potting Medium
Plastic and clay pots each have advantages. Clay pots can be more aesthetically pleasing, but they can absorb salts and minerals that will eventually harm the roots of your orchid. Plastic pots retain moisture, so clay pots are preferable if you tend to overwater your plants.
Fir bark is the most common potting medium for orchids, or you can use a commercially prepared orchid potting mix. Expect to repot your orchid about every two years, when it will probably have outgrown its original container.
Provide as much filtered bright light as you can for your moth orchid. Fluorescent lights can be used to supplement or replace sunlight. You can tell your orchid is getting the proper amount of light if the leaves are light- to medium-green and the plant looks vigorous and healthy. Too much light will scorch the leaves or turn them yellow or reddish.
Use blinds or sheer curtains to soften strong sunlight, or simply move your plants a few feet back from the window. Too little light results in weak, spindly plants with dark green leaves. If your orchid needs more light, make the transition to a brighter location very gradually – over several weeks. When your orchid blooms, keep the colors of the blossoms from fading by moving the plant out of the direct sun.
Phalaenopsis prefer daytime temperatures in the mid-eighties and night temperatures in the low sixties (Fahrenheit). The night temperature is the most important: orchids may not flower if the temperature does not drop 10 to 15 degrees Fahrenheit every night. If your Phalaenopsis has lots of healthy foliage and never blooms, make sure you are getting enough temperature fluctuation during the course of the day.
Moth orchids will thrive with a daytime relative humidity of 40 to 70 percent. Most houses with central heating do not achieve this level of moisture in the air during the winter months. You can increase the overall humidity with a room or whole-house humidifier. Another approach is to increase the humidity around your plants.
You can set your potted orchid in a tray filled with water and gravel – the water will evaporate from the tray and increase the ambient humidity – or you can drape plastic sheeting around your orchid-growing area. Orchids also need air circulation, so if you use plastic sheeting avoid making it airtight. Misting orchids serves no real purpose because the benefits are extremely short-term.
Try to keep your Phalaeonopsis from drying out between waterings. Stick your finger into the potting medium up to your second knuckle and water when the medium is still slightly moist. Use room temperature water and soak the potting medium thoroughly. Remember that plants in clay pots usually need to be watered more frequently than those in plastic pots.
Houseplant food with a ratio of 30-10-10 (nitrogen to phosphorous and potassium) is best for orchids grown in fir bark. Use 20-20-20 fertilizer with other potting mixes. Feed your moth orchids “weekly, weakly” – that is, each time you water the plant, add half the amount of plant food suggested on the label.
Moth orchids usually bloom from winter to spring. The flower spike breaks out of the side of the plant, just above the roots, and grows upward. After the flowers fade, cut the stalk just below the node that produced the first flower and the stem will branch and bloom again.
Your local library or bookstore has many books about growing and propagating orchids, such as All About Growing Orchids, by Rick Bond; Orchids Simplified, by Henry Jaworski; and Orchids for Everyone, by Brian Williams.