Light is essential for plant life processes, and optimum levels ensure healthy, long-lived indoor plants. In general, there are three categories of light intensity for interior plants: high, 150–1000 foot-candles (fc); medium 75–150 fc; and low, 25–75 fc. It is important to match plants with locations that satisfy their basic light requirements. Many reference books and Cooperative Extension publications provide interior scape professionals and home gardeners with information on the light levels necessary to maintain plants indoors. A wide variety of light meters is available for measuring light intensities in indoor environments