It is a universally-known fact that sunlight is indispensable for plants to conduct photosynthesis which transforms light energy to chemical energy for vegetative growth and flowering. And to solve the contradiction between our ambition to raise plant production and nature’s unpredictability, human wisdom has come up with indoor growing. However, for years, indoor growers have been confined to a couple of choices when selecting grow lighting—high pressure sodium, metal halide and more recently, compact fluorescent. Although in each case the purpose is to imitate sunlight, these grow lighting does not work efficiently. Through trial and error, LED grow lights have come to our rescue. Though started as a niche market with its own brand of cult-following, LED grow lights are now viewed as not only an energy saving alternative to traditional growing light but also a means to grow more in a narrower and smaller space. As is well-known, sunlight is white light, which means it consists of light wavelengths from the entire visible light spectrum (red, orange, yellow, green, blue, and violet) and invisible forms of light radiation such as UV. Though different plants have different lighting requirements, most plants thrive with only a limited range of light—reds and blues. Often blue LED grow lights are adopted to raise vegetative growth for hardy plants while red LED grow lights are used to enhance the flowering and fruiting stages. It is estimated that HID/CFL bulbs only have about 15 percent of their emitted light usable for plants to conduct photosynthesis while LED grow lights have high up to 90-99percent of their emitted light usable. Here the extreme efficiency of LED grow lights stands out. What is interesting is that high efficiency does not mean more electricity used—actually, LED grow lights use only 20% to 30% of the electricity compared to metal halide and high pressure sodium lighting. Another advantage to add is that LED grow lights give off much less heat than metal halide or high pressure sodium bulbs so that you won’t burn yourself or scorch those tender plants. Besides, less heat also reduces your worries about heat related damage and rapid dehydration. Still, there are many people who are in favor of those traditional grow lights. The reason is quite simple—cost; LED grow lights are more expensive, which means more investment is needed. But taking into consideration the fact that LED grow lights are much more energy-saving and durable than traditional grow lights, they actually cost substantially less from the long term. Hobbit Hill Farm, a commercial hydroponic tomato growing operation in New Hampshire has been capable of saving 50% on electricity by adopting LED grow lights. With HID lights, the electricity costs them over $1000 per month while after changing to LED grow lights, the farm is able to save over $500 per month. All together with the grant gotten from the USDA and the local electric company, NHEC, the farm will be able to offset the upgrade cost in only 2 seasons, based only on electricity savings and not taking into account the production increased by using LED grow lights. In addition to cost reduction, LED grow lights also provide healthier plants, because they don’t have the highly toxic mercury used in metallic vapor and fluorescent lights. And with the advancement of science and technology, LED grow lights undoubtedly will play a larger role in indoor gardening and hydroponics. So why not have a try and enjoy the benefits of scientific advancement?