A lighting device and assembly which incorporating an independently powered array of at least two types of LED lights that each give off specific wavelengths of light for growing plants. The assembly includes at least two of the lighting devices in conjunction with at least one high intensity bulb commonly used for indoor horticulture, where the assembly is adjustable for dimensional changes in the subject plants as they grow. A timing method for applying specific durations of each type of light which effectively simulate sunrise, daylight and sunset by allowing the plant to awaken naturally, absorb more light during the day and prepare for sleep at night, giving the plant more rest—all leading to more healthy plant growth.