PROBLEM TO BE SOLVED: To provide a method which can improve the growth effect of the plant than before, in the plant cultivation method promoting the growth by irradiating the plant with artificial light.SOLUTION: A plant cultivation method separately and independently performs following steps within the fixed period: (A) irradiating the plant with red light； and (B) irradiating the plant with blue light. Amounts of fertilizer components such as nitrogen, phosphorus, and potassium in a plant cultivation environment of the step (B) which irradiates the plant with blue light are less than those of fertilizer components such as nitrogen, phosphorus, and potassium in a plant cultivation environment of the step (A) which irradiates the plant with red light. Preferably, nitrogen included in a culture medium of the step (B) irradiating blue light is 10-15 me/L, phosphorus is 1-4 me/L, and potassium is 2-6 me/L. Nitrogen included in a culture medium of the step (A) irradiating red light is 15-20 me/L, phosphorus is 3-6 me/L, and potassium is 6-9 me/L.【課題】植物に人工光を照射して成長を促進させる植物栽培方法において、植物の育成効果をより一層高める方法を提供する。【解決手段】赤色光を植物に照射する手順(Ａ)と、青色光を植物に照射する手順(Ｂ)とを一定期間内に別個独立に行う工程を含む植物栽培方法において、青色光を植物に照射する手順(Ｂ)における植物栽培環境の肥料成分としての窒素、リン、カリウムの量を、赤色光を植物に照射する手順(Ａ)における植物栽培環境の肥料成分としての窒素、リン、カリウムの量より低くする。好ましくは、青色光の照射手順(Ｂ)における培地に含まれる窒素を１０～１５ｍｅ／Ｌ、リンを１～４ｍｅ／Ｌ、カリウムを２～６ｍｅ／Ｌとし、赤色光の照射手順(Ａ)における培地に含まれる窒素を１５～２０ｍｅ／Ｌ、リンを３～６ｍｅ／Ｌ、カリウムを６～９ｍｅ／Ｌとする。【選択図】 図１
