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.