Basic Indoor Culture
The best reference for how to grow an orchid is how it grows in its natural habitat. There is
tremendous variation in the growing habits of different genera of orchids and there is also variation in the conditions of our homes where we hope to cultivate them. The questions to ask are, what amount of light does it require, what temperature range does it do best in, does it need especially high levels of humidity and air movement, and what kind of watering and potting medium will it require? Most orchids grow on high tree branches as
epiphytes and thrive with lots of air movement. Some of the most popular orchid generas for growing indoors are
Phalaenopsis, Oncidium, Cattleya, Paphiopedilum, Encyclia, Pleurothallids - and there are more - which do not require
especially high light, humidity, air movement or a drop in
temperatures at night. It is just about impossible to satisfy the light-level needs of orchids such as Cymbidiums and Vandas indoors.
Species classified as intermediate or warm growers will best match the temperature ranges of most homes, with lows in the 50’s and averaging 60-80F.
Light is the most important aspect to growing orchids in a home. Placement of plants is crucial to the success of indoor culture. East, west, and south-facing windows are fine, but pay close attention to the amount of light each window receives as the sun moves throughout the day and year. When direct sun is coming in it should be diffused by a curtain or light shade tree outside. However, direct sun in the early morning or late
afternoon is okay. South-facing windows are great as they are
generally the brightest, but direct sun should be diffused and the heat should be kept under control. Plants should be placed as close to the window as possible; keep in mind there is
considerably less light in the middle of a room. Most orchids require a certain amount of light to bloom; therefore, if your orchids are not blooming there is a good chance you are not
getting enough light. Watch the color of the foliage; if after a month the foliage has become a darker shade of green, it may not be receiving enough light; if it becomes much lighter, it may be getting too much light.
Any natural sunlight that you can give the plants is extremely beneficial. However, supplementing low sunlight levels with artificial light can be easily accomplished. Grow-lights are
specially formulated to give light similar to the spectrum of the sun. Many people have had good success with a combination of cool and warm fluorescents or cool fluorescent and incandescent bulbs. Light intensity decreases by half at a distance of 6 inches away from the light bulbs. Plants requiring higher light such as cattleyas will need their leaf tips just 2-3 inches away.
One of the benefits of artificial lighting is that the amount of light can be controlled by a timer and you can stretch the
duration of light longer than day length. Some orchids,
especially species, are sensitive to day length and won't bloom if given more than actual daylight. It is best to reproduce day length or increase it slightly and change it 4 times a year: January - March, 12-14 hours, April - June, 14-16 hours, July - September, 12-14 hours, October-December, 10-12 hours.
The best way to tell when to water is by the weight of the pot; depending on how dry the orchids’ potting mix is, it will be heavy or light. Water well the day before it will be
completely dry. We recommend sitting the pot in the sink and running lots of water through it, letting the mix absorb water and drain. You might wait twenty minutes or so and run water through a second time through (perhaps with fertilizer). Avoid watering too frequently and never leave the plant sitting in a saucer of water, as the roots are subject to rot. Most orchids will do well watered every one-to-two weeks. You may water more
frequently in hot, dry weather, and less frequently in colder weather. Also, large plants in small pots dry out faster; plants overpotted or in old, decomposed bark stay wet longer (see repotting below). Orchids love purified but not softened water.
A simple balanced fertilizer used all year around works fine. Add one teaspoon to one gallon of water with a
fertilizer such as a 7-9-5 or 1/2 teaspoon to one gallon of water for a more concentrated fertilizer such as a 20-20-20. Try to use fertilized water for every watering. Occasionally leach the
accumulated salts out of your orchid by watering copiously with unfertilized water.
Most orchids should be repotted every one to three years. An orchid needs repotting when it has grown far over the edge of the pot or its potting mix has broken down. One
indication of bad mix is if it feels crumbly or soft, or if the plant is loosing roots and wobbles in the pot. Repot into new, firm mix such as fir bark or coconut husk (some species do best in a particular type of mix) after removing the plant from its old pot and cleaning old bark and dead roots away. The lower parts of the roots of a root-bound plant may also be cut away, always using sterilized tools to cut between plants. Use the smallest pot that fits around the root ball without cramping it; sometimes you will wash the same pot and use it again, sometimes go slightly larger, or if the plant has lost roots, it may go smaller. An
alternative to re-potting for several epiphytic types is to set a whole pot with healthy, overgrown plant and roots into a slightly larger empty pot. The roots on these types are fine growing around in the air space between pots with no need for additional mix. Some of our largest specimens are still in their original 3 or 4-inch pot, set in a 5 inch pot, set in a 6-inch pot, and on up. Most orchids can be divided into multiple, smaller plants, but when left as one plant can become great specimen plants with multiple blooms.
Blooming problems: If your orchid is not blooming each year it may not be getting enough light or it may need a cool
temperature drop. To cool your orchid in order to initiate blooms, place it outdoors in a shaded location for at least two weeks when night time temperatures get down to the middle 50’s.
Pests: Sometimes common to orchids are insect-pests which feed off flower buds, like mealy bug, white fly, and aphids. If visible these can be removed with a Q-tip and rubbing alcohol without damage to the buds. Insects that have laid eggs in a plant or are pervasive like scale should be treated with a garden insecticide such as Ultra-Fine Pesticidal Oil at intervals of ten days until the pests are gone..
Displaying Orchids at Home: Any orchid can be brought inside to enjoy while in flower. To maintain orchids in bloom the plants must not be allowed to completely dry out, nor should they be kept constantly wet. The best method is to water plants
thoroughly with good quality water until wet, then allow to almost dry out before watering again. Misting the roots with good water can also help to keep your plant turgid (firm-leafed). Flowering plants or plants in bud should not be placed near fruit which gives off gases or in the direction of heat or A/C vents. This can cause bud drop or flowers to perish faster.
Improving Your Luck: Keep your plant labels - Know the names - Get care instructions when you buy a plant - Use artificial lighting whenever needed - Grow plants outside whenever possible - Maintain air movement and some humidity - Pay attention to watering - Don’t allow plants to sit in water - Go slow, learn as you go - Get a book on indoor orchid growing. - Join a local orchid society.