Many plants can be grown indoors using fluorescent lighting systems. Plants are the only organisms that are capable of producing food using light, a process known as photosynthesis. However, there are key differences between fluorescent and natural sunlight.
Sunlight vs. Fluorescent Light Wavelengths
Sunlight provides the complete spectrum of light wavelengths, which is visible through rainbow color -- red, orange, yellow, green, blue, indigo and violet. Cool white fluorescent lights provide a high proportion of blue light.
Fluorescent Grow Lights vs. Sunlight
Fluorescent lights used specifically for growing plants are available and attempt to reproduce growth-encouraging aspects of natural sunlight by providing both red and blue wavelengths. Blue light encourages vegetative growth, while red light encourages flowering. However, Oregon State University Extension advises they are more expensive but not much better than cool white fluorescents.
Plants are adapted to having a regularly scheduled day and a night. Sunlight dissipates at the end of the day, sending plants into important night cycles. Indoor gardeners, however, must remember to turn off fluorescent lights on a regular schedule. The University of Missouri Extension suggests using an automatic timer for this, as it's easy to get off schedule.