A lighting system and method for the growing of a plant seedling is disclosed, including at least one light source (30) for illuminating the plant seedling (39) with grow light during growth stages of the plant seedling growth process, and a controller for the controlling the spectral power distribution of the grow light emitted from the light source (30) such that the grow light in at least some growth stages of the plant seedling growth process comprises more energy in the blue wavelength range than in other growth stages of the plant seedling growth process. In use cases where the grow light is supplementing available daylight, an additional sensor (33) may be used to measure the amount and spectral composition of daylight and control the grow light such that spectral power distribution of total light received by the plant seedling is controlled accordingly.
