PROBLEM TO BE SOLVED: To provide a simple and energy-efficient plant cultivation method by artificial light irradiation in which plant cultivation effect such as excellent growth acceleration effect can be obtained.SOLUTION: In a plant cultivation method (a cultivation method based on circadian rhythm of a plant is excluded) in which a red light irradiation step S1 of irradiating plants with red light illumination light, and a blue light irradiation step S2 of irradiating plants with blue light illumination light are performed, irradiation time on each step is 3 hours or more and less than 48 hours, irradiation cycles C1,C2 that consist of the red light irradiation step and the blue light irradiation step are performed at least for 2 cycles or more in a certain period, and procedure is started by either step of the red light irradiation step and the blue light irradiation step in the irradiation cycles.【課題】簡便で、エネルギー効率が良く、優れた生長促進効果などの植物栽培効果を得ることが可能な人工光照射による植物栽培方法を提供する。【解決手段】赤色光照明光を植物に照射する赤色光照射ステップＳ１と、青色光照明光を植物に照射する青色光照射ステップＳ２と、を行う植物栽培方法において、各ステップの照射時間を３時間以上４８時間未満とし、赤色光照射ステップと、青色光照射ステップと、からなる照射サイクルＣ１、Ｃ２を一定期間内に少なくとも２サイクル以上行い、かつ照射サイクルにおいて赤色光照射ステップ又は青色光照射ステップのいずれか一つのステップで手順を開始する、植物栽培方法（植物の概日リズムに基づく栽培方法を除く）。【選択図】図１
