Properly lighting potted plants provides a challenge for many indoor gardeners. To grow well, plants need adequate light and the right kind of light. Providing consistent lighting from the sun year-round in indoor locations may be difficult, making it necessary for indoor growers to supplement or replace sunlight with artificial lighting.
Learn about your plants---each plant is different. Select plants appropriate for indoor growing and suited to the available light. For example, a cactus will rarely do well in even the brightest artificial light while some types of ivy and philodendron live happily with little natural light.
Watch your potted plants for signs of inadequate and or excess lighting. Plants suffering from lack of light start to drop lower leaves and grow spindly stems with small, new leaves. They may also fail to bloom. Plants that get too much light look faded and dry, or may wilt when the sun is most intense.
Place potted plants that need full sun or direct sunlight about 2 feet from south or southwest-facing windows. These plants can also go in sunrooms or brightly lit windowsills. Plants that need bright or indirect sunlight should sit about 4 feet from a window with eastern or western exposure, or about 5 feet from a window with southern or southwestern exposure.
Set houseplants that need low light or partial shade in north-facing or east-facing windows that only receive morning sun. Keep these plants at least 5 feet away from south and southwest-facing windows. Place plants that prefer shady places in dark staircases, hallways or shaded windows.
Provide incandescent lights for plants that need a little extra light. These bulbs provide enough light from the red and blue parts of the spectrum to help plants grow, especially if the plants also receive some natural sunlight. A few hours of light from a table or floor lamp or from an overhead fixture can effectively supplement sunlight without requiring the purchase of special bulbs and lighting setups.
Light houseplants with fluorescent bulbs if they receive little to no sunlight. Fluorescent bulbs are bright enough for plants, with lots of light from the blue part of the spectrum that plants need. A mixture of fluorescent and incandescent light gives blue and red light for growth and blooms, or use fluorescent bulbs designed especially for growing plants.
Give foliage plants 14 to 16 hours of artificial light a day and flowering plants 12 to 16 hours. Also provide at least 8 hours of darkness every night. The heat from artificial lights is more drying for plants than sunlight, so check the soil's moisture level regularly and water plants on a schedule.