What Lights to Use to Grow Plants

A grow light added to your indoor garden or greenhouse can extend the growing season of your plants and boost their growth. It can be difficult to get the proper light requirements when planting indoors. Each plant has different lighting requirements, and responds best to different light spectrum. A light spectrum is the color of light within the full spectrum. The blue spectrum of light enhances leaf and vegetative growth, while red encourages flowering. It's important to choose the right light for the type of plant you want to grow indoors to ensure proper photosynthesis.

Fluorescent Grow Lights

Fluorescent grow lights are excellent for stimulate the growth of seedlings. They shine the full light spectrum. Fluorescent lights also emit lower heat than most other lights, which means they can be put directly over seedlings without causing damage. The fluorescent lights are not very useful for supply light to larger areas like a greenhouse, but a perfect for smaller areas. The T-5 fluorescent lights are especially useful for plants because they are more efficient and lightweight compared to other fluorescent lights. They produce a greater light intensity, and use less energy.

Metal Halide Lights

The metal halide grow lights emit the violet and blue light spectrum. Often, they are used as a primary light source when sunlight is not available. Metal halide lights last for long periods of time that average 10,000 hours. The violet and blue spectrum of the lights help plants to develop strong roots. The light also promotes leaf and vegetative growth, which makes the light useful for green leafy vegetables. Metal Halide lights are best used to start seedlings, and support earlier plant development.

High Pressure Sodium Lights

The high pressure sodium grow lights cast the orange and red light spectrum that is prevalent during the summer and fall season outdoors. The spectrum encourages flowering and fruiting in plants. The lights are most often used for mature plants that are beginning to produce fruits. They often last for up to 18,000 hours and are used in larger spaces like a greenhouse to supplement other light sources.

Other Lights

LED lights are very energy efficient, however, they are not useful as a grow light. They cast an unnatural light appearance on plants. The LED lights benefit plants at about the same rate as incandescent lights, but for more cost. Both LED and incandescent give poor lighting to plants. Incandescent lights cast a reddish yellow spectrum, and emit too much heat. Incandescent can be used to supplement other lights for house plants, but that's about it.

Keywords: fluorescent lights, metal halide, high pressure sodium

About this Author

Based in Ann Arbor, Michigan, Robin Coe has reported on a variety of subjects for over 15 years. Coe is the former publisher of the politics and art magazine Flesh from Ashes. She has worked to protect water and air quality. Coe holds a Bachelor of Science in journalism with a double-major in international politics from Bowling Green State University.