Disadvantages of CFL Grow Lights

Any experienced indoor gardener will tell you that having the right kind of light is essential if you want your plants to grow and flourish healthily. Indoor grow lights should mimic the same kind of light in which the plant naturally grows, and you have several options.

Compact fluorescent light, or CFL, bulbs have the qualities of being cooler and more efficient, which makes them a popular choice, both cost- and heat-wise. However, CFL bulbs have disadvantages as well.

Plants synthesize different kinds of light for different purposes. CFLs are ideal for vegetative growth, encouraging healthy leaves, while high-pressure sodium lights are better for flowering or fruiting. Thus, most CFL bulbs are only effective for a certain length of a plant's life cycle---if it flowers or fruits, the gardener will likely have to switch bulbs or move the plant into better light..

CFL bulbs do exist that contain a wider light spectrum range. However, these bulbs are generally tubular, so they may not be compatible with the grow space. It's important for the gardener to be sure what kind of bulb they are getting and whether it serves the appropriate purpose.

Another disadvantage CFL bulbs have compared to others, like metal halide bulbs, is that the light, even at the proper spectrum, does not shine with the same intensity as other kinds of grow lights. Fluorescent bulbs generally burn more efficiently, and also cooler than metal halide or high-pressure sodium bulbs, but the light may not be strong enough to penetrate the distance between bulb and plant for the plant to be able to take full advantage.

One solution that may resolve this problem is to situate the plants and lights closer to one another.

The relatively short distance needed between the lamps and the plants to be effective---around 30 cm---for proper growth creates a situation where the design of your indoor garden is limited by the distance between the light and the plants. You may have to reconfigure your garden depending on the light intensity or spectrum range needed. Fluorescents, both compact and tubular, tend to emit cooler light of limited spectrum, so to be effective you must either use many bulbs, taking up more space, or you may have to switch lamps.

As an indoor grower, you may have to limit your indoor plantings to low-light plants like hostas or African violets. Alternatively, you may place only small young plants in early stages of growth under the lights, moving them to other places later.