PROBLEM TO BE SOLVED: To provide a plant seedling cultivation method that can grow seedlings in which spindly growth does not occur, which gives rise to thick stems, and has good growth even after planting.SOLUTION: The plant seedling cultivation method promotes growth by the irradiation of artificial light on plant seedlings and includes a period (A) during which blue illumination light is continuously illuminated, and a period (A-1) during which blue illumination light and red illumination light are continuously irradiated over a period 30% to less than 80% of the period (A) during which blue illumination light is continuously illuminated.SELECTED DRAWING: None【課題】徒長が無く、茎の太い、定植後にも生育が良好な苗を栽培できる植物苗の栽培方法を提供する。【解決手段】本発明の植物苗の栽培方法は、植物苗に人工光を照射して生育を促進させる植物苗の栽培方法であって、青色照明光を連続的に照射する期間（Ａ）を有し、前記青色照明光を連続的に照射する期間（Ａ）を行う時間の３０以上８０％未満が、青色照明光および赤色照明光を連続的に照射する期間（Ａ－１）である。【選択図】なし
