<P> A grow light or plant light is an artificial light source , generally an electric light , designed to stimulate plant growth by emitting an electromagnetic spectrum appropriate for photosynthesis . Grow lights are used in applications where there is either no naturally occurring light , or where supplemental light is required . For example , in the winter months when the available hours of daylight may be insufficient for the desired plant growth , lights are used to extend the time the plants receive light . If plants do not receive enough light , they will grow long and spindly . </P>
what kind of light is a grow light
an artificial light source designed to stimulate plant growth by emitting an electromagnetic spectrum appropriate for photosynthesis