Orchids in your attic? Begonias or bromeliads in your basement? An herb garden in the kitchen? All this and more is possible if you join the legions of enthusiastic indoor-light gardeners.
I've been sold on indoor-light gardening since 1960, when I produced my first healthy tomato plants, compact, flowering, and ready to set fruit when I planted them outdoors.
Gardeners had long been wanting to bring sunlight indoors, but it wasn't until 1938, when the first fluorescent tubes were introduced, that indoor-light gardening really began.
Growers experimented, bits of information filtered into the horticultural literature, and gradually amateur gardeners began using fluorescent lights. Some started a few seeds under one fixture; others developed sophisticated plant rooms where hundreds of plants thrived in conditions controlled by humidifiers, fans, hygrometers, timers, and automatic-watering systems.
It doesn't take fancy equipment or a huge investment of time and money to enjoy the results of indoor-light gardening. You can begin with one or two 4 -foot fixtures, the kind you use in a basement shop and can buy inexpensively from your local store, where you can also buy fluorescent tubes.
The least expensive and most readily available tube is Cool White, satisfactory alone or in combination with Daylight or with the more expensive Gro-Lux Wide Spectrum. Add an inexpensive timer, and you're ready.
Next, decide where to garden. You don't have to go to Dorothy Kaye's extreme. Recently she removed all the fixtures from a bathroom in her Denver condominium and converted that space into an orchid room. The logical spot for a light garden in your house my be in the basement, family room, kitchen, or garage. Currently mine is in the laundry room, where my plants love the humidity.
Location established, hang the fixture 12 to 15 inches above your growing area and set the timer to the desired length of daylight.
There are two approaches to this kind of gardening. You can do everything possible to create the perfect environment for one specific type of plant. For example, the cactus specialist might provide a 50-degrees F. temperature and a short 8-hour ''winter'' day. Or you can develop conditions in which a large number of different plants will be reasonably happy by selecting a 14- to 16 -hour day and aiming for a 75 degrees F. ''day'' temperature with 10 degrees F. drop at ''night.''
I can't supply absolute rules about where to place a plant in your light garden. Even in a small setup you will find microclimates. An experienced light gardener, such as George Elbert, author of ''The Indoor Light Gardening Book,'' says he continually experiments.
Let your plants be your guide. Look at them as you water. If an African violet is getting bunchy in the center, move it farther away from the lights, perhaps to the ends or sides of the fixture. If a geranium is getting too leggy, cut it back and put it closer to the lights. You will not burn any leaves unless it actually touches the tube.
Looking at your plants frequently also helps keep pests to a minimum. If you see any insect, first identify the bug and then take appropriate action.
When you water, you can pour water into the top of the pot, stand the pot in water, or flood a tray, using wicks or capillary mats. Whichever method you prefer, pour plain water through the pots every six to eight weeks to prevent the buildup of fertilizer salt.
How much you should water depends on many variables - pots (porous clay or water-retentive plastic), pot size, day length, humidity, temperature, amount of vegetation, variety of plant, and soil mix.
Choose any soil mix you like. Indoor gardeners are succeeding with many different recipes. However, if you want to add compost or topsoil from your yard , pasteurize it before use to eliminate any pests.
Many light gardeners like artificial mixes. Buy a commercial blend, or combine your own peat, perlite, and vermiculite.
Just as I don't like to feast one day and then fast for a week, so it makes sense to me to constantly feed my plants, using a very dilute solution for all waterings.
Remember that, in a light garden providing a 16-hour day year-round, you must feed regularly year-round. Disregard all house-plant books that recommend little or no food for indoor plants during the winter. That recommendation applies only to windowsill gardening during winter's short, gray days.
The two problems most light gardeners have are lack of humidity during the winter and fungus problems during summer days.
How you solve the humidity problem depends on where in your home you are light gardening. If you are growing in an enclosed area, such as my laundry room or Mrs. Kaye's bathroom, it's easy to provide enough moisture. In a large open basement, however, try enclosing the light garden area. Sheets of polyethylene stapled from rafters to floor, for example, provide one quick and inexpensive solution. Within any confined area, you can then add a humidifier, if needed.
You can also increase humidity by using the pots-on-pebbles routine in any location in your house. By keeping the pebbles constantly wet, water evaporates around the plants and keeps the air around them more humid. Aim for 50 percent humidity. To check this level, use a hygrometer.
As you become a more sophisticated light gardener, you probably will want to acquire a hygrometer and a maximum-minimum thermometer so that you know what your conditions are.
Fans and fungicides are the two best methods of combating summer molds, mildew, and damping off. Again, look at your plants - particularly pans of germinating seedlings - and quickly treat any problem with a fungicide.
Good air circulation also minimizes bacterial and fungus problems. The addition of a small fan will keep the air moving gently and promote healthy plants.
My plants all grow under 2-tube, 4-foot fixtures. While it is considered a low-light-intensity garden, this simple setup can raise a wide variety of plants. Now, in January, African violets, gloxinias, smithianthas and other gesnerias, miniature roses, miniature geraniums, begonias, and the seedlings of the new double impatiens are flowering in my light garden. I also am growing rhododendron, cyclamen, primrose and lewisia seedlings, ferns, and hoyas. And I've just started the geranium seeds for next summer's flowers.
During late winter, in fact, my light garden doubles in size because of seedling production. If you haven't tried raising your plants from seed under lights, now's the time. Your choice of plant material is much more interesting than the selection in any garden center. Also, it's more fun and it's even economical.
As an example, last year a geranium in a 4-inch pot sold for $2.50 here in my area of North Carolina. I could have raised 25 Carefree geraniums under lights for the necessary four months at a seed cost of $3.75 and an electricity cost of
If you're interested in reading more on the subject of light gardening, there are several good books available, including Elbert's. The Brooklyn Botanic Garden offers an excellent series of handbooks. One is No. 93, ''Gardening Under Lights,'' which costs $2.25. Write to 1000 Washington Avenue, Brooklyn, N.Y. 11225.
As a final suggestion, join the Indoor Light Gardening Society of America. Membership provides contact with a large number of gardeners using light gardening in a myriad of ways. Annual membership is $8. If interested, get in touch with Robert D. Morrison, membership secretary, 5305 S.W. Hamilton Street, Portland, Ore. 97221.