Plants need sunlight to provide them with energy to grow and flower. Plants grown indoors with little or no natural sunlight will need an additional source of light to grown properly. When a plant is grown entirely on artificial light, you may need to use a specially made plant light, such as Gro-Lux or Plant-Gro. Normal desk lamps can also be used to supplement a plant's light. Use the supplemental light for a few hours at dawn or dusk to increase the plant's day, especially in the winter when sunlight is scarce.
Hang a work-light fixture in the place where you wish to grow the plants. Plants need to be located about 6 to 12 inches from the light source. Light intensity will drop rapidly the farther way the plant is from the source. Use an adjustable fixture to change the distance from the plants as the plants grow larger. If you cannot move the light source, you will need to adjust the height of the table the plants are resting on.
Place a reflector underneath the plants to increase the amount of light reaching the plants. A simple reflector could be a sheet of bright white paper, a mirror or even shiny aluminum foil. Arrange plants so that they do not shade each other.
Place plants under the center of the light fixture, where fluorescent lights provide the strongest light. Avoid placing plants at the edge of the light source.
Use a timer on the lights to give the plants a regular amount of light each day. Plants without natural sunlight need between 16 and 18 hours of light, while those with some natural light will only need 12 hours of artificial light.