A compact fluorescent bulb is a light bulb that produces light in a method similar to the fluorescent tubes found in many office buildings and home kitchens, but it differs in shape. When used properly, the right kind of compact fluorescent light (CFL) bulb can supply supplemental light to indoor plants. The CFL bulb differs from the usual incandescent light bulb, and has some advantages and disadvantages in comparison.
In contrast with long and thin fluorescent tubes, compact fluorescent light bulbs have tubing that is coiled so it is shaped more like an incandescent light bulb. An incandescent bulb uses an electrified coil of wire that glows and produces light. The light source in fluorescent bulbs comes from electrifying gas. According to the NAtional Aeronautics and Space Administration, a fluorescent bulb electrifies mercury plasma, which glows invisible ultraviolet (UV) light. The inside of the fluorescent bulb is coated with reactive paint that glows when UV light shines on it.
Compact fluorescent light bulbs are more durable than fluorescent tubes and use less energy than incandescent light bulbs. Traditional fluorescent lighting tubes tend to lose light power and go dark toward the ends of the tubes; compact fluorescent lighting lacks the end-gaps seen in tube lighting. Compact fluorescent bulbs are smaller and can be installed in a standard light socket.
Even compact fluorescent bulbs designed for growing plants can lack the right colors and light intensity needed for some more light-hungry plants. To increase the intensity of a compact fluorescent light system, a gardener can use reflectors to catch more light, install a combination of differently colored compact fluorescent light bulbs, or add other types of light bulbs to correct inadequate light. In most gardens, a source of natural light can easily supplement a fluorescent lighting system.
According to the University of Missouri Extension, indoor plants thrive best on light sources with red or blue light. Yellow light, the light color emitted from most incandescent light bulbs, is not as useful to a plant's growth. An indoor lighting setup using incandescent light bulbs needs a source of blue and red rays added to it to keep plants healthy. If a sunny window is not available to supplement these colors, a cool-colored or full-spectrum compact fluorescent light can help add the missing light to the plant's growing area.
Light Fixture Distance
Compact fluorescent lights run cooler than larger fluorescent plant lighting fixtures, allowing the gardener to place the light closer to the plant without burning it. This is helpful for gardeners working with tight gardening spaces. Placing the light closer to the plant is also more eco-friendly, since it makes use of more of the available light. For best results using a compact fluorescent bulb, the lighting fixture should be adjustable so it can be moved to maintain its distance from the light as the plant grows. Lighting fixtures should be placed between 6 and 12 inches from the top of the plant, depending on the intensity and heat of the compact fluorescent bulb.