For ideal plant growth, nothing beats natural sunlight. Grow lights fall short of the sun's perfection, but they compensate for short days and low light indoors. Light-emitting diode (LED) lights take grow light technology into new dimensions. Instead of trying to replicate the sun, they target the quality of light plants need most. The wide-reaching results affect everything from space travel and greenhouse growing to home gardeners starting early seeds.
Plants and Light Quality
Light impacts essential plant growth at every step. Brightness and light duration guide photosynthesis and a plant's ability to grow, bloom and bear fruit. Grow lights vary in intensity and quantity of light, but also in the quality of light that plants receive. Light quality depends on the color or wavelengths of light produced. Natural sunlight provides the entire quality spectrum, evidenced in rainbows and prisms. Grow lights mimic the sun with mixed results. Different types of grow lights emit different color ranges. Each color affects plant growth in a different way. When it comes to light quality, LED grow lights shine.
Effects of Light Color
Research on the ways light color affects plant growth remains in its infancy. Different light qualities and combinations affect rooting, flowering and general growth in different ways. The effects vary between types of plants. Plants absorb little green light; the reflected light makes plants look green. Red and blue light have the greatest impact overall, but each gradation along the spectrum yields different results. Blue light fuels germination and leafy vegetative growth, while red and blue combine to spur flowering. Some wavelengths cause shorter stems; other colors make plants tall. With LED grow lights, the possible combinations open wide.
LED Growing Potential
Long-lasting, energy-efficient LED lights convert electricity directly into light in a sustainable, cost-effective alternative to traditional grow light bulbs. But the bigger news is their ability to be tailored to emit pure, specific light ratios. By targeting wavelengths that maximize photosynthesis, LEDs evoke more plant response and waste less light. An LED can be produced to match a very specific purpose. NASA research into LED grow lights for use in space found higher antioxidant levels in edible salad crops grown with certain LEDs. Because they stay cool, the lights can be close to plants in tight areas.
Grow Lights Comparisons
The potential for LEDs to outperform other grow lights increases with every technological advance. Incandescent lights generate orange-red light and lots of heat. Short-lived, they use electricity inefficiently. Fluorescent lights deliver red, green and blue light levels. Good for germination, they stay cool but lack wavelengths some plants need. Plus, environmentally sound disposal can be difficult. Heat-producing, high-intensity discharge (HID) lamps waste energy producing light colors plants don't need. According to research led by the U.S. Department of Agriculture and Michigan State University, preliminary results show LED grow lights save energy and deliver the same or better plant results.