Natural Light

• Natural light is the best source of light for plant growth, due to the warmth that the plant gets from the sun. While plants may grow tall under artificial light, this is generally because they want to reach the warmth from the light bulb. However, artificial light can be a good supplement for light during dark winter months.
  
  

Red and Blue Lights

• Red and blue lights help plants grow. However, they should only be used when plants are already meeting their light requirements. Both red and blue lights are used to control photosynthesis. Red light controls maturation, height and flowering and seed production. Blue light controls leaf development. Used alone, red lights will make a plant grow spindly and tall and blue lights will make a plant be short and stocky with thick stems, dark leaves and very little flowers.
  
  

Artificial Light

• The amount of artificial light for helping a plant grow faster depends entirely upon how much natural light it already receives and what type of plant it is. Foliage plants typically have lower light requirements, while flowering plants prefer more light. Plants should be located within a few feet of a 100 to 150-watt bulb during the evening. Alternatively, lamps placed directly above the plant, and 4 feet away, also give enough light and do not cause damage from the heat.
  
  You can use a small, portable reading lamp or a large, elegant lamp as a supplemental light source. Turning these lamps on for one or two hours during the morning and night, especially during winter, will visibly improve the plants. Plants stuck in a dark corner will benefit from having four to six hours of artificial light placed directly overhead.
  
  Incandescent lights work well for supplementing natural daylight for plants with low light requirements. However, keep in mind that they do not provide enough light to meet the needs of flowering plants, but only of foliage plants. These lights give off a large amount of red light and infrared radiation, which converts into heat, resulting in the burning of leaves. So these light sources should be constricted to small areas that need very little extra light.
  
  Fluorescent lights, however, work very well for helping plants grow faster. They emit two and a half times more light per watt than incandescent bulbs. Fluorescent tubes offer both red and blue output, as well as cool or warm white lights.