All about miniature plants and gardens indoors and out

The three tiny rooms of the Greenwich Village apartment possess a total of two narrow, old-fashioned windows; yet in its darkest corners bloom some of the most gorgeous gesneriads I’ve ever seen. In similar fourth-floor quarters on New York’s dreary 41st Street, miniature orchids and other tropicals make a flamboyant jungle. In an attic in Levittown, a cellar in Bayside, a heated garage in Westchester, plants make it look like July in January, living their life cycles over and over again without ever seeing the sun. The life they must have for existence is supplied by electricity.

Time was, when windows were the only place in the house where plants could be grown. But since government scientists first grew corn to maturity under artificial light at Beltsville, Maryland (back when I had more interest in boys and dating than in gardening), that picture has certainly changed. Now, all sorts of plants can flourish in the most unlikely places. Home decorators can use plants ornamentally wherever they look best, and create the conditions in which they grow best. The hobbyist who can’t afford a greenhouse can have a most satisfactory and inexpensive substitute in unused places in the house. And a greenhouse owner can double his growing space without adding another section of glass.

Naturally enough, scientific research in this field has been aimed at helping florists, farmers, and others to whom plants are a business; but amateurs have benefited, too. The principle of photoperiodism—that some plants set buds and flower only when nights are long, some others only when nights are short—led to delaying the flowering of commercial chrysanthemums by interrupting the long night with a period of light. Amateurs have used the same principle to force tuberous begonias to flower in winter by lengthening the day with several hours of artificial light.

The discovery and isolation of a light-sensitive enzyme, photochrome, has been applied to cyclic lighting—a less costly method of regulating flowering by flashing lights on and off at intervals. Probing the mysteries of photochrome has also given orchid fanciers a better understanding of their plants’ blooming habits and has even made it possible, with some species, to have flowers twice or three times a year, rather than just once.

If I may be permitted a slight prejudice, it’s these amateur benefits that make me happiest. I love plants; and I think millions of other people do. From the windows of my commuting train I see New York tenement tenants wistfully watering morning glories that pathetically climb fire-escape trellises. More prosperous Manhattanites spend small fortunes on florists’ plants to bring the breath of green life into their sterile apartments; and their disappointment, if the plants die, is pitiable. Suburbanites have a yen to make a hobby of collecting plants. And now they can. I know, because I did.

In our roomy, old-fashioned cellar in Bayside we had triple-decker shelves fitted with fluorescent lights where we grew everything from begonias (finally, a collection of more than 350 varieties) to annuals for the gardens out of doors. That was some years ago. The information about lighting was sparse, inconclusive, and often confusing. Our light intensity was inadequate, and there were other deficiencies which we would correct were we setting up that cellar greenhouse today. But our successes were fascinating, our failures a challenge. And the hours we spent working with those plants in the cellar often were our only moments of refreshment and relaxation.

The hobbyist, with his dividends of fun, is not the only one who benefits from this new concept of light and plants. There is the home home-decorator, the woman of the house, who finds in plants the sort of ornament the entire family enjoys. She’d like the graceful lines of a vine tumbling down from the mantel, jewel-like flowering plants on the shelf of a corner cupboard, a garden of green atop the room divider between the living and dining areas. Frustratingly, she discovers that where the plants are most effective, too often they won’t grow and flourish. It is usually because there is insufficient light for their life processes. But now, she can set up a light on the mantel, install fluorescent tubes beneath cupboard shelves, or let ceiling lights flood the plants above the room dividers. Such lighting has a double effect, it enables the plants to flourish, and it gives a dramatic accent to the décor of the house.

Artificial lighting is a help even for the casual grower—one who has only a few plants, whether by happenstance, for the fun of it, or simply because “a house is not a home” without a plant or two. Table, desk, and floor lamps can be used to supplement the natural light from windows. Too often windows are shielded by trees or the house next door, or perhaps it is winter and there isn’t enough light to keep most plants in a thriving condition. Just turning on a lamp so that the rays fall on a plant can lengthen the hours of light enough to bring out bloom that might otherwise be impossible.

Miniature plants and gardens are, of course, shining prospects for growth under artificial light. They take so little space, and since there is a limit to the height, width, and depth a single installation will illuminate, you can make the most use of it if you are growing the little fellows.

Here’s how the “jungle garden” came to be our source of continual refreshment and pleasure. Our living and dining rooms, both rather small, are separated partially by deep shelves. The previous owners of the place, devout music-lovers, used the shelves for their hi-fi set and stacks of phonograph records. Our record player—pardon me, our stereophonic hi-fidelity music box—has its own cabinet, and that left a gap in the divider between the two rooms. We naturally thought of plants, particularly the tender tropical miniatures I collect. Since we still hope to do extensive remodeling, the garden was not built permanently into the shelves, but was constructed as a separate case.

We are fortunate in having a generous friend who loves to work with fine wood, and can make cabinets with the precision of the real professional. The case he turned out is a beauty. It measures eighteen inches by twenty-four inches inside. The top rests on strong metal rods at the corners. Window glass slides horizontally in the grooves cut in the top and bottom, enabling us to open or close the case as need be. The inside of the top is painted white, thus reflecting the light from the lamps downward on the plants. We use both fluorescent and incandescent lights which are mounted on the underside of the top. The bottom of the cabinet is lined with the heaviest plastic we could find.

At first the case was used as an indoor greenhouse for many potted plants that need protective warmth and humidity. Several inches of vermiculite in the plastic lining were kept moist constantly, with the sides being opened or closed for ventilation.

Later, we filled the bottom with rich potting soil and put the plants’ roots right in it—climbers, creepers, tiny bush-shapes and trees. This turned out to be more of a “jungle” than we expected. Some notably delicate residents seeded themselves and started families. A dainty cissus strung itself langorously from one end to the other. The creeping fig nearly strangled the frail, whiskery bertolonia. But the planting was a source of delightful surprises—a bud here, a flower there, increasing colonies of some delicacies we hadn’t been able to grow at all, before.

Several years ago a bookcase which I set up in my office as a garden was the object of considerable attention—how much I never realized until I dismantled it and gave away the plants. Then, I was bombarded with questions—and even some complaints that I had taken away this spot of greenery. From the night watchman up to the president of the company, people missed those plants. Some even thought I must have been fired.

There is a little house in Levittown, one which I always enjoyed visiting. The second floor has two finished rooms, one of which then was the office-den of the hard-working Elvin McDonald of Flower and Garden. (He has since moved to Kansas City.) His tiered plant table with fluorescent lights was there for a functional reason, but it had a decorative value as well. In other homes I’ve seen plants growing by hundreds under lights in unused bedrooms, single specimens displayed in shadow boxes with circular fluorescent tubes, decorative gardens thriving in all sorts of dark corners. With artificial lighting taking care of the space problem, just about anyone can grow plants.

However, before your enthusiasm flies too high, consider this sobering caution. Like anything else, artificial lighting works best only when it is properly planned and executed. Light must have the quality, intensity, and timing that plants need. Specific, accurate, up-to-date information is not always easy to find. Despite many fascinating discoveries and developments, this is still a relatively new horticultural principle, and there is still much more to be learned. Before he begins, the newcomer should locate the very latest and most reliable information; and the experienced grower should keep posted on the constantly changing rules. It has been my pleasant discovery that the big power-and-light companies, ever alert to develop new outlets for their product, are keenly aware of the possibilities of artificial-light plant propagation. Many of them are setting up departments to help horticulturalists. If you are puzzled, try your light company for information. It may take a few phone calls and letters, but eventually I know you will find some likeable chap wanting to help you.

Although it is not necessary to become a botanist, I feel it is urgent to have a clear conception of how plants grow, and particularly how they use light. While we can’t all be electrical engineers, it is also helpful to have some basic facts about electric lights and how they relate to plant growth. But if it were possible, I think I’d consider writing the facts I have with invisible ink. Who knows but what today’s list of rules will be obsolete, and outmoded by new discoveries, before this book can be published?

Botanical Principles

For normal growth and flowering, plants must have light of the proper sort, intensity, and duration. Thus the leaves can perform their function of making starch, then sugar—the mysterious process called photosynthesis. Besides normal growth, plants require an extra supply of sugar and starch for producing flowers. True, plants need light, but they also need dark to convert food into energy and growth. And this means complete dark. It has been shown that if light falls on so much as a single leaf, the entire plant continues to operate as if it were day.

For normal growth and flowers, plants require a certain balance of the red and blue rays of the spectrum. In general terms, blue rays are especially effective in developing leaves, stems, and other vegetative growth, and often in greater proportions for seedlings as compared with mature plants. In general, the red rays keep plant growth sturdy, regulate the development of buds and flowers, affect the germination of seeds and the rooting of cuttings.

For normal growth and flowers, different sorts of plants need light of different intensities—depending usually on available light in their natural habitat. Again in a general sense, light of more intensity is needed for flowering as contrasted with the needs for healthy foliage. But light intensity requirements vary with various types of plants.

For normal growth, and flowers, some plants need dark periods of greater duration. This is the principle called photoperiodism. By now a good many plants have been classified as to this requirement, but there are many others whose needs are yet to be determined. Chrysanthemums, poinsettias, and Christmas cactus, for example, will set buds and flowers only when there are more hours of dark and fewer hours of light. These are called long-night plants. Tuberous begonias, and other summer-flowering types, come into flower when nights are of short duration, and are called short-night plants. Those plants that don’t seem to care one way or another are called day-neutral. For the sake of consistency you might even call them night-neutral. It is also thought that there is some relation between the duration of light and dark periods and temperature. Thus it can be seen how much research is yet to be done. A challenge of course, but that is what makes our scientists great.

Electrical Principles

Artificial light is not the same as daylight—it doesn’t have to be. It needs only to supply the right kind of light (blue and red rays) of suitable duration and intensity. Because it is constant, and consistent, the intensity (as measured in foot-candles) does not have to equal the brightness of a sunny day at high noon. Daylight waxes and wanes from dawn to dark every day, and may be very dim on cloudy and rainy days. Artificial light, coming from generators, is not dimmed by clouds or other external conditions. Duration is controlled by a light switch, or a time clock.

Incandescent bulbs are an adequate source of red rays for plants, but give little blue. They get burning hot, are comparatively expensive, and actually are inefficient to operate. Incandescents are also a source of far-red rays that delay flowering on long-night plants and operate in reverse for short-night plants. According to U. S. Department of Agriculture scientists, incandescent light used as a supplement to fluorescent light “improves the growth habits of many kinds of plants, but is seemingly not required by others.”

Until the introduction of the new Gro-Lux tubes in 1961, fluorescent lamps have given light with more blue than red, and in varying proportions according to the types of lamps. Fluorescent tubes do not get burning hot, and they are comparatively inexpensive to operate, and also efficient. In using the older types, those created especially for illumination, it is important to come as close as possible to the proper balance of the red and blue rays needed by plants. For some plants it has been sufficient to use only fluorescent tubes. For some of the other types many growers use 10 per cent of the wattage in incandescent bulbs.

But the new Gro-Lux fluorescent tubes, developed by Sylvania Electric Products, Inc., are especially for plants and not for illumination. They give a lavender-looking light made up of red and blue rays which are carefully balanced to suit plant needs. Growers who have used them report a spectacular improvement in plant appearance, in plant health, in faster rooting of cuttings, and in increased flowering. If demand warrants it, no doubt other electrical manufacturers will introduce their own brands of fluorescent tubes for plants.

Obviously, in growing plants under artificial light there are so many variable elements it is impossible—and extremely unwise—to set down hard-and-fast rules. The types of plants to be grown, whether the installation is primarily decorative or functional, and the possibility of continuing research outdating your work, all should be taken into consideration when any installation is set up and put into operation.

CONSTRUCTION AND INSTALLATION

Again, I must write in general terms. I have neither the knowledge nor the experience to explain the intricacies of wiring, ballasts, circuits, and the like. This technical information is available from your electrical supplier and from equipment manufacturers, and often is on the cartons in which the parts are packed. Our installation was so outrageously large we had to hunt up a friendly contractor for help. He was a sympathetic man who loved plants and was fascinated by the idea of growing them under lights. Also, he was a cautious person, mindful of the fact that our electrical system was about twenty-five years old. And that stamped it as being an antique (as your light-and-power men will tell you). Since our basement floor was likely to be damp at times, heavy waterproof cables with special plugs and outlets were used, and grounded to prevent shocks, etc. Be careful about your electrical system, especially if you are going to go into anything as elaborate as our first enthusiasms. Don’t build a firetrap for yourself. It’s hard on the plants, not to mention the old homestead.

Whether your plants are to be grown in a garden, or in pots on benches, on shelves, or in a greenhouse-like case, the lineal proportions will be determined pretty much by the space that is available in your house, basement, greenhouse, or perhaps, as was in my case, your office. In small decorative planters twenty-five-watt fluorescent tubes (two feet long) are used most frequently. However, it is important to use enough of them, lined up closely to each other, to give a light of sufficient intensity. In fluorescent tubes the light is most intense in the middle and tapers off sharply at the ends. Since short tubes have more end—and less middle—they give off less light. The “shorties” are less efficient, as your plants will tell you.

The distance between the tubes and your plants also affects intensity. The closer they are, the stronger the light. If possible, hang your fixtures on chains so that they can be raised or lowered. Adjust them to accommodate the taller plants and then raise your “little fellers” on upended pots, bricks, or boards so they will not be cheated of their share of light. Please remember, the greater the distance between light and plant, the more tubes you will need. Distance determines the number of tubes!

For greater intensity, and efficiency, forty-watt tubes (four feet long), or even larger, are usually recommended. If these are to be hung from the top of a case or cabinet, the simple strip fixtures are sufficient. If there is to be no “ceiling” directly above the lights, or if it is a decorative arrangement where glare might hurt the eyes of those who see it, use the industrial fixtures with shield-like reflectors. (In planning your light-garden, please don’t forget that the fixtures are a few inches longer than the actual tubes.)

If the case which you may be planning can be enclosed, at least on three sides, it will be easier to maintain the needed humidity. If the enclosing sides are opaque, they—and the “ceiling” above the lights—should be treated so the light rays are bounced back and the plants receive the extra benefit. In our cabinets we usually applied several coats of flat white paint on the inner surfaces. But once, under the blandishments of the aluminum industry, I lined a cabinet with their foil. It was plain foil, not the crinkled sort, so I did my own crinkling. Then I smoothed it out and fastened it in place with a staple gun. Plain foil, like high-gloss white enamel, seems to reflect the light every place except where it should be, on the plants.

In one of the installations we had at our place on Long Island I found it impossible to put in enough fluorescent tubes for the plants we wished to grow. Since they were day-neutral varieties, we made up for the lack of intensity by increasing the length of time the lights were used. Up to a point, increasing the light-hours will help to compensate for the lack of intensity—just to a point, however, and then the old law of diminishing returns takes over. Plants must not be under light so long that they fail to get their necessary periods of darkness. It is as essential as sleep is to a human being—perhaps more so.

OPERATION

In planning a light installation try to squeeze out a few extra dollars for an automatic timer. It will help to guarantee success for the operation. You’ll have a certain peace of mind if you tend to be absent-minded. No more will you fret through a P.T.A. meeting, a movie, or a concert wondering if you turned off the lights on your plants. The timer will have done it for you. If you happen to have an enclosed case—one tight enough to conserve the humidity—you can very easily go away on a short trip (a day or two at most) and feel confident your pets will not suffer. If you have postponed buying a timer—actually, they are not expensive—and have to leave your plants for a day or so, it is better to turn off the lights completely. They’ll suffer less than if the lights are going full blast. But for peace of mind, particularly that of the plants, we’ve always used automatic timers. At one time we had three of them. When I was ordering one from a mail-order company, my husband was buying me one as a birthday gift. And at the very same time the electrical contractor who redid out light system donated one in the interests of our begonias. We had them popping on and off at all hours of the day and night. We even hooked a percolator into one for the morning coffee.

As I look back over our experiments of a few years ago, I find there are more plants which are day-neutral (night-neutral if you prefer) than plants which are short-night or long-night. For these day-neutrals, fourteen to sixteen hours of fluorescent light (of sufficient intensity) every day, all year round, will keep them happy and thriving. They won’t know the difference between winter and summer, spring and autumn, Florida or Long Island. That has been our experience, but now I find opinions vary on whether hours of light should be lengthened or shortened in spring and autumn for these seasonal changes. (There is still plenty of room for experimentation. For instance, the light requirements for many plants are still to be worked out—even for closely related plants within various types.)

Some growers, those who specialize in plants for which they know the light requirements, turn on the lights at dawn and turn them off at nightfall. This is a year-around schedule. Others who have plants of assorted types, or of undetermined light requirements, maintain a constant fourteen-hour growing day. And they are often surprised by even second, or third, bursts of bloom. A nice surprise, if you ask me.

INTENSITY

Here again we find the needs of plants vary and fluorescent-light setups vary accordingly. If possible, measure the light in your growing area. The readings of a photographic light meter—the same instrument you employ in your photography—can be translated into foot-candles. Or you can get a meter that registers foot-candles. For advice, consult your camera dealer, or check with your local power-and-light company. Here in Redding we find the Connecticut Power and Light Company vitally interested in artificial-light plant propagation.

Again “in general,” house plants that require “full sun” when grown in a window need 1200 to 1500 foot-candles of artificial light, and for fourteen hours a day. Foliage plants will get by with 500 to 600 foot-candles. At about 1000 to 1200 foot-candles many plants, and I’m thinking of begonias and gesneriads in particular, will be robust and floriferous.

Should you find it difficult to figure light intensity as suggested above, you might follow the formula worked out by an old friend on Long Island, Elaine Cherry (Mrs. Norman Cherry, the wife of one of our engineering friends). Her formula is easy to follow. “A single forty-watt tube will serve a space approximately four feet long by six inches wide.” Small plants that need intense light can be set up close to the tubes.

Here is a tip—ever notice how your television picture is dim but brightens appreciably when you take a dust rag to the surface of the glass? The same is true of your light fixtures. Wipe them off now and then. Clean tubes give more light than dusty ones, and new tubes give more light than old ones. When a tube darkens at the ends, that means it has seen better days and should be replaced. According to Mrs. Cherry, it is a good policy to replace tubes after five thousand hours of service and not wait for the dwindling light to curtail the rays your plants need. While you are at it, it’s smart to insert new starters.

TYPES OF TUBES

Until the introduction of the Gro-Lux lamps, we had to choose types designed primarily for illumination. And there were as many choices and combinations as there were tube types. In a private and somewhat limited survey, I’ve found that when only one type of tube was used, cool white was to be preferred. In combinations of equal or two-to-one proportions, some growers use daylight and natural tubes; others prefer daylight and de-luxe warm white. And there are those who go for cool white and de-luxe warm white. Those who supplement their lights with 10 per cent incandescent light seem to favor all daylight fluorescent tubes.

The object of all these different combinations is to get the most favorable balance of red and blue rays. If you are a hobbyist who grows plants for the love of them, and not necessarily for their value in interior decoration, the new Gro-Lux tubes are less complex and less troublesome. You don’t have to be a light expert to get results and have fun with your light-garden.

CARE OF PLANTS

Temperature, humidity, soil, fertilizing, potting—almost without exception, plants growing under artificial light need the same care as window-garden plants. But since the light is an artificial substitute for natural sun and light, watch for signs that the plants are not entirely satisfied with it. When they stretch out, get long and lanky, or the foliage has a weak, wan color, set the plant up closer to the tubes, or over toward the center where the light is strongest. You might do well to make room by shifting some of the plants that have been in the center. Sometimes when a plant has too much light it will become stunted. Until a more exact rule book is written, you will have to use your own good common sense.

Here is the big worry many growers have; the failure of their pets to flower. More often than not that means insufficient light, insufficient red light, or perhaps both.

As of this date it is probably ten years since we first started toying with plants under artificial lights. I say “toying” because it was just that—purely for fun. We kept no records. When frost was in the air we dug up flowers and brought them indoors. My husband even brought in eleven goldfish which he feared would be glacéed in an outdoor pool. We put everything under lights with the fish in terrariums. Eventually he spent thirty dollars for a pool in an untidy corner of the living room. Thirty dollars, not counting the electric bill, I felt was a little expensive for a dollar’s worth of goldfish. I sold twenty dollars worth of photographs of that pool and then included one of them in my book All About Vines and Hanging Plants. Eventually he allowed me, very grudgingly, to place episcias around the pool. Mites moved in on them. He sprayed for the mites and killed all of the fish. He replaced the fish with eleven others. Thus the cycle continued.

All the time we had those indoor plantings our neighbors kept asking us what plants were good for lights and what lights were good for plants. Frankly, we couldn’t answer. Ten years ago that book hadn’t been written.

We tried just about everything less than five feet tall. We had wonderful results with African violets, begonias, orchids, and gesneriads. We even had a morning glory which singed itself on a steam pipe. All of them loved the kilowatts.

(In Chapter 6 I have indicated certain plants which are suitable for propagation under artificial lights.)