H I D Lights The best light for growing plants is the High Intensity Discharge (HID) light. These lights are highly efficient and offer intense light that is the correct color for plants (roughly 10 times the intensity of fluorescent lights). They consist of a highly efficient reflector, commercial grade bulb and a ballast. They come in two types, Metal Halide and High Pressure Sodium. Select the wattage based on the size of your garden, and the type of light based on the plants you wish to grow. Select the bulb to further refine the spectrum of light emitted. Kelvin Temperature of Visible Light