A: Many people make the mistake of assuming that since orchids are native to tropical rainforests, they must be watered several times a week. Unfortunately, watering this frequently will kill the roots of any orchid in short order. The general rule of thumb for orchids grown in the home is to water every 5 to 12 days, depending on the type of orchid, the temperature the plant is grown in, and the time of year. During the warm summer months when days are long, more frequent watering is required than in the cooler, shorter days of winter.
There are three basic types of orchids, as far as watering is concerned: those that should be kept evenly moist at all times; those that should be allowed to nearly dry out between waterings, except when in active growth; and those that should always be allowed to dry out a bit between waterings. The guidelines below list the major varieties of orchid in each type.
Varieties to keep evenly moist (not soggy or wet) at all times:
Paphiopedilum, Miltonia, Cymbidium, Odontoglossum,
Varieties to keep evenly moist during active growth, allowed to dry out between waterings when not:
Cattleya, Oncidium, Brassia, Dendrobium.
Varieties to keep nearly dry between waterings:
Phalaenopsis, Vanda, Ascocenda.
In a family of plants as large as Orchidaceae, there are, of course, exceptions to these rules. Always be sure to ask for watering instructions when you purchase a variety of orchid with which you are unfamiliar.
Q: How often should I be fertilizing my orchids?
A: Be sure to use an orchid food that is formulated for orchids and follow the instructions on the label. In general, most orchid fertilizers recommend usage once a month. Less frequent fertilizing may stunt growth and inhibit flowering; more frequent fertilizing may burn the roots and leaves and inhibit flowering. For complete step-by-step instructions on how to feed your orchids,
Be sure to use an orchid food that is formulated for orchids and follow the label instructions. In general, most orchid fertilizers recommend use once a month. Less frequent fertilizing may stunt growth and inhibit flowering, more frequent fertilizing may burn the roots and leaves and inhibit flowering. For complete step-by-step instructions on how to feed your orchids,
Q: What do I do when my phalaenopsis stops blooming?
A: If your plant has healthy, with thick, green leaves that have not become wrinkled or drooping, cut the old flower stem up high, just above a "node" and just below the lowest bloom. The plant will frequently send out a new flowering branch at that location. If your plant has thin, wilted leaves, or if the plant is small, with only 3-to-4-inch-long leaves, it is best to cut the flower stem all the way down, so that the plant does not weaken itself by blooming again right away. Carefully water and fertilize your plant to build it back into shape for future flowering on a brand-new stem. This can take up to a year or more, as Phalaenopsis, like most orchids, is a relatively slow-growing plant.
Q: I am growing my phalaenopsis orchid in the house but they never bloom. What can I do?
A: The most common reason for any orchid not to bloom is insufficient light. Move your phalaenopsis plants to a window where they will receive strong, but indirect light (near a south-facing window is ideal). You might also try lighting your plants with a fluorescent light fixture placed about 1-2 feet above the foliage. Give up to 12 hours of supplemental light per day. Phalaenopsis will also develop flower spikes in response to a cool period of about four weeks with night temperatures of 55F. After the cool treatment, raise the night temperature back to the normal 60-65F minimum. See if these changes to your growing conditions help to stimulate your plants to bloom.
Q: How do I know if my orchid is getting the proper amount of light?
A: One good indicator is leaf color. Generally speaking, the leaves should be bright green rather than dark green. Dark green indicates too little light while reddish green indicated too much light. Those orchids requiring higher light intensities, such as cattleyas, dendrobiums and oncidiums, should be placed in a south or west facing window, but be sure to protect the leaves from the hot mid-day sun with sheer curtains or move the plants back from the window on hot summer days. Miltonias, phalaenopsis and paphiopedilums prefer lower light intensities and should be located further away from the window or placed in a window facing east or north.
Q: The orchid in my window suddenly developed black blotches on the leaves. Is it sick
A: It sounds like your plant has a bad case of sunburn! Longer, brighter days can increase the light intensity in your window so that the leaves get too hot and burn. You need to move your plant back from the window or put up sheer curtains to help protect it from direct sunlight. As the light intensity decreases in the fall, move your plant closer to the window again. Frequently check their leaves and watch for any fading of their green color, especially on those parts of the leaf closest to the window. This is an early indication that they are being exposed to too much sun.
Q: How do I know if I need to re-pot?
A: A newly potted phalaenopsis should be able to remain in its growth media two years before repotting. When there are many, long roots over the edge of the pot, this plant has most likely been growing for several years since its last repotting. If your plant is not currently in bloom, you should repot now. Be sure to remove all dead roots that are usually dark-colored, soft and mushy. Sometimes they may be dry, with a fiber running through the middle of the root. Center the plant with all of its roots down in the pot and add moistened bark until the level of the bark is just below the bottom of the lower set of leaves. Wait a week before resuming your normal watering and fertilizing routine.
Q: My phalaenopsis has been in flower for quite a while and now it seems to be forming what looks like a new plant on the flower stem! Will it grow if I pot it and what type of soil is best?
A: Congratulations! With proper care you will have a new plant, identical in every way to your original phalaenopsis. Wait until the new plant has developed a strong little root system of its own, with two or three roots at least one to two inches long. Then, carefully cut the plantlet, called a keiki, from the flower stem and put it in a very small pot of seedling bark for its first potting. After a year or two, move up to medium-sized bark in a four to five inch pot. Alternatively, you can pot the keiki in special orchid sphagnum moss. Be sure to go light with the fertilizer for the first few months. Once the plant has established itself, as evidenced by increased leaf growth, start with full-strength fertilizing.
Q: I would like to try growing orchids under lights in my house. What type of light fixtures and bulbs do you recommend that I try?
A: Many hobbyists have been successful with just ordinary fluorescent lights. You can also buy the more expensive fluorescent plant lights that give off a broader spectrum of light. An inexpensive way to achieve similar results is to use one cool-white fluorescent to one warm-white fluorescent bulb. The cool-white bulb will give off more of the blue wavelengths of the visible spectrum while the warm-white gives the plants more of the red end of the spectrum. Such a broad spectrum of light helps assure better growing and blooming. Some people also add one incandescent bulb to enhance the red end of the spectrum but be sure you don't burn your plants with the heat given off by this type of bulb.
Q: My mother gave me an orchid that is called Dendrobium Phalaenopsis. I am confused. Is this a type of phalaenopsis and how do I care for it?
A: There are more than one thousand different species belonging to the genus Dendrobium. One species, Dendrobium phalaenopsis, has been frequently used to make hybrids. These hybrid orchids are noted for their upright, branching sprays of brightly colored flowers that resemble those of the genus Phalaenopsis. They basically prefer the same growing conditions as for phalaenopsis but dendrobiums will perform better in a brighter location in your home. Place them in a bright window, but without direct hot sun (south facing window is ideal). Sheer curtains will protect your plants from the burning rays. The ideal minimum night temperature is between 60-65F. The ideal day temperature is 75-85F. Phalaenopsis type dendrobiums like to have their potting medium dry out a bit between waterings.
Q: What causes the new growth on my miltonia (``pansy orchid") to be crinkled?
A: Crinkled leaves are an indicator that the plant received insufficient water while the new leaves were developing. This can be caused by either loss of roots due to keeping the growing media too wet, which has killed most of the roots, or by simply not enough water to an otherwise healthy root system. Miltonias prefer to have their roots constantly damp, but never soggy. Older growing media will tend to hold water for longer periods of time so be careful not to overwater. Miltonias also prefer lots of humidity, with 50-75% being the ideal amount. Light, morning misting of the foliage is helpful in hot, dry conditions but be sure to keep standing water out of the leaves or soft rot may develop, especially if there is poor air circulation around your plants.
Q: What is the difference between a terrestrial and an epiphytic orchid?
A: Terrestrial orchids live on the ground, usually in a water-retentive humus of rotting wood and leaves. These orchids need a constantly moist, but never soggy, medium in which to grow. Paphiopedilums and cymbidiums are examples. Epiphytic orchids live on the branches of other plants -- usually trees. They are not parasites -- they obtain no food from the trees on which they grow. Epiphytic orchids have "air-roots" which are accustomed to drying out in between periods of rain. These orchids need an open medium in which to grow and the roots should be allowed to become moderately dry between waterings. Cattleyas, vandas, phalaenopsis, and dendrobiums are common examples.
Q: What's the difference between a hybrid seedling and a meristem seedling?
A: A hybrid seedling is an orchid plant that has been produced by seed through the hybridization process. Two parent plants were used to produce the seed and the individual seedlings all have their own unique characteristics, like brothers and sisters in a family. A meristem seedling is a seedling that has been produced using the cloning process. Each "mericlone" plant has an identical genetic make-up and each meristem or mericlone plant will look exactly the same, like identical twins.
Q: I have just purchased a mottled-leaved paphiopedilum. Do I care for this plant the same as the plain, green-leaved paphs?
A: Like their solid green-leaved relatives, the mottled-leaved paphiopedilums prefer less light than many orchids and are well suited for growing in your home. Place them near a bright window but out of the direct sunlight. Both types of paphs should be kept continuously moist but not soggy. The solid green-leaved types are cool growers that prefer night temperatures of 50-55F and day temperatures of 75-80F. The mottled-leaved types are warm growers that prefer night temperatures above 60F and day temperatures of up to 85F.
Q: What are the most common orchid pests?
A: Snails and slugs often hide in the potting media where they chew on young root tips; they also come out at night to chew on the leaves and stems. There are several insect pests that are common: Aphids (small sucking insects) and thrips (small chewing insects) attack tender new growth, flowers and buds. Scale insects form a brown or black crust on leaves and stems. Mealybugs also attack the leaves and stems forming a white cottony mass. Consult a local garden center for products to control these pests.