The invention relates to a method for artificial illumination of a plant, the method comprising the steps of: controlling an illumination system to illuminate the plant, the emitted light having a first spectral distribution and a first intensity level, the first spectral distribution and the first intensity level selected for optimizing growth of the plant； detecting, using a sensor, the presence of stress in the plant； if stress is detected, controlling the illumination system to illuminate the plant with light having a second spectral distribution and a second intensity level, the second intensity level being lower than the first intensity level. The invention also relates to an illumination system for artificial illumination of a plant according to the method above.
