WINDOW GREENHOUSE
Available light, or sunlight, is the first consideration in selecting plants for a window area, or in selecting the window for the plants you have or want. Light can be brighter (it even comes from overhead) inside a greenhouse that extends out from the window. You can buy these in all combinations of measurements, ready-made and assembled, or ready to be assembled. Or you can make them, or have them made, from the materials sold in most hardware stores for those who build their own screens and storm windows.
The greenhouse fits flush to the outside of the window frame and is sealed with a calking-gun after it has been screwed firmly in place. It may rest on the outside of the sill, or be supported by metal or wooden brackets on the underside. The top lifts open for ventilation, and the opening is covered with a screen. Glass shelves permit light to penetrate fully. A tray at the bottom holds moist vermiculite to humidify the air.
The window sash can be removed or not, as you wish. You can install an inexpensive, thermostat-controlled heater for extra warmth in winter.
If the light is right, and if humidity can be kept high enough, an installation such as this can contain not only all sorts of window-garden plants, but also many of those recommended for the greenhouse in Chapter 6.
A window greenhouse filled with growing, blooming plants is an attractive outdoor decoration on almost any house. Its effect indoors is always cheerful and refreshing. And it is especially suited for miniatures. Numerous small plants make a better decorative effect than a few large ones.
(For suitable plants, please refer to list at end of Chapter 6.)
CHAPTER 2
MINIATURE GARDENS WITH ARTIFICIAL LIGHT
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.
Interesting combination of bookcase and lights for African violets and begonias of several varieties
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.
Tropical plants with controlled light, heat, and moisture make a “jungle garden”
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.
The author’s New York office light-case planted with gesneriads, begonias, and other 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.
Light shelves of medium height with begonias of many sizes and varieties (note miniatures down front center)
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.