The disclosed plant cultivation method and lighting device can repel insects while also controlling the flowering reaction or avoiding delaying the flowering of short-day plants such as chrysanthemums. Said method uses illumination from a plurality of light sources, each of which emits light having a peak wavelength in the red-to-green region. Each light source goes through a synchronized or independent flashing pattern in which the emission intensity changes cyclically, each cycle consisting of a bright period with a prescribed width and a dark period with a prescribed width, the dark period having a lower time-average brightness than the light period. The duty cycle of the flashing pattern, as defined by formula (1), is at most 50%. (1) Duty cycle = width of bright period / (width of bright period + width of dark period) × 100% In at least part of the region illuminated by a plurality of light sources, the combination of the illumination patterns from said plurality of light sources produces an insect-repelling effect.
