1. All lights must have some type of reflector, either homemade or purchased, to concentrate the light down on the plants.



2. Light bulbs and tubes must be spaced at definite distances to give the plants the correct amount (foot-candles) of light.

3. Lights must be left on long enough to accomplish the job they are intended for Install fluorescent lights and their reflectors in pairs of 40-watt tubes. One white tube and one daylight tube will give the plants a proper balance of red and blue light rays. Two daylight tubes and two 25-watt incandescent or a multiple of these will also give the proper lighting.

A new type of fluorescent light, called high output, supplies almost double the amount of light given by ordinary fluorescents. These lights, with special starters, are available on order from major electric companies.

An automatic timer, to switch lights on and off, will be invaluable as a labor and time saver.

Note that two 40-watt tubes will light an area 2K by 4 feet.

Short-Day Plants

Short-day plants need a specific number of solid hours of darkness to form flower buds. Under natural conditions they will do this as autumn approaches. But there are two ways to change their flowering period. You can hasten it by shading the plants to supply them with extra hours of darkness. Or you can delay flowering by breaking the darkness-induced budding cycle with additional or intermittent light.

Covers of heavy black sateen, plasticized cloth, or building paper can be used to shut out light. This covering is placed over the plants in late afternoon, perhaps 5 o'clock, and left on until 7 o'clock the following morning. Plants requiring such treatment should be grown in an area that will accommodate the erection of a wire frame around them to facilitate placement of the shading material.

The time to start shading depends on when you want to sell the plants.

Chrysanthemums require 2 to 4 weeks of artificially induced darkness to start flower buds ahead of normal season schedule; poinsettias shaded about 2 weeks beginning the first part of October will flower for Christmas sales.

Shade the Christmas begonia (Melior) from October 10 to October 20 to make it produce a heavy crop of flowers for Christmas sales.

If you supply short-day plants with 2 to 6 hours of additional I evening light from 25-watt bulbs spaced 2 feet above the plants, I you can break and delay their budding cycle. With proper manipulation of light and darkness you can have them in flower through most of the year. Many commercial plant suppliers, especially chrysanthemum specialists, furnish exact data for each variety they sell.

You can change and control the flowering periods of such important profit-makers as kalanchoe, poinsettia, gardenia, China aster, and Christmas cactus, by shading or lighting them.

Long-Day Plants

Long-day plants, as a rule, need 14 or more hours of light per day to develop good flowers. In winter when days are short, give these plants 4 to 6 hours of added light. Sixty to 75-watt incandescent, as many as needed, are spaced 3 feet apart and hung about 4 feet above the plants. They will supply the right amount of light.