Different Types of Indoor Grow Lights for Plants

Indoor grow lights are a great resource for devoted gardeners. Especially for those who do not have access to long growing seasons, or abundant outdoor soil space, grow lights for plants offer a unique opportunity for fresh, homegrown fruit, vegetables, flowers, and herbs throughout the year.

While conventional incandescent lighting can be useful for highlighting plants, it does not do much for plant growth. High intensity discharge (HID) lights, such as metal halide and high pressure sodium bulbs are more effective for enhancing plant life. They are also very energy-efficient, as compared to incandescent lamps. Fluorescent grow lamps for plants are also beneficial, offering a more gentle, inexpensive option. Of all the various types of indoor grow lights, which is the most effective for growing plants indoors?

Metal Halide Grow Lights

Metal halide grow lights are the most ideal type of lighting source for indoor plants because they provide a spectrum of light that is very close to natural sunlight. Their Color Rendering Index rating (a measure of how close artificial light is to sunlight) ranges from the 60’s to the 80’s, with 100 being a perfect score.

For the plants, metal halide lights provide all the necessary colors in the light spectrum, including red to stimulate flowering and blue to regulate growth. They promote strong, vigorous growth. In the home environment, the lighting is a beautiful white color, offering a natural look, reminiscent of a clear, sunny day in the garden outdoors. They are considered to be the best indoor growing lights for professional cultivators and gardening enthusiasts.

High Pressure Sodium Grow Lights

High pressure sodium bulbs are also considered to be HID lamps, suitable for serious indoor gardeners. They are specifically used for encouraging plants to flower as the yellow-orange-red light rays are ideal for flowering and fruiting. What is interesting with using these lights is that the plants tend to be tall and leggy, and even appear unhealthy. In fact, plants do thrive with high pressure sodium grow lights.

Like metal halide lights, sodium bulbs are highly efficient. They are also cost-effective, lasting up to two years. In the growing industry they are often used in greenhouses where plants get plenty of blue spectrum light from the sun. The golden yellow sodium lights can be used to increase fruit and flower harvests.

Fluorescent Grow Lamps for Plants

What are the benefits of using fluorescent lighting to grow plants indoors? Fluorescent grow lights are beneficial because they are energy-efficient, effective, and they do not emit the same intensity of heat that HID lights give off. Look for full-spectrum fluorescent bulbs for starting seeds indoors and for enhancing the growth of house plants. Compact fluorescent grow lamps can be used for growing indoor plants to maturity.

Tips for Using Indoor Grow Lights for Plants

Whether upgrading greenhouse productivity with high pressure sodium bulbs or starting seeds indoors with fluorescent grow lamps, indoor grow lights are a useful, and sometimes necessary tool for gardeners and horticulturists. It is important however to always keep safety in mind, to care for the lights, and to use lamp systems properly to ensure optimal growth.

• Look for products whose entire lighting system has been certified by Underwriters Laboratories (UL).
• Read the instructions that come along with grow lamps and follow them.
• Be sure to regularly turn off the lights as directed to allow the plants to respire and the bulbs to cool.
• Keep the bulbs and lighting systems free from dust.
• Replace bulbs when their time is done. Grow lights may still turn on when they are passed their life duration, but they may not be effectively treating the plants any longer.
• Be sure to understand the needs of the plants. Some do well with a certain light spectrum colors, while others do not.
• Be aware of the distance between the plants and the indoor growing lights, especially with metal halide and sodium lamps.

With care and efficient use, growing lights can truly expand the possibilities for all serious gardeners.

References:

“Indoor Plant Grow Light Guide.” (ACF Greenhouses)

“Plant Grow Light Options.” (Progressive Gardening)

“Gardening Under Lights.” (Gardener’s Supply Company)