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.
Miniature roses, begonias, a birdbath, and ground cover made this charming little formal garden.
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.