An object of the present invention is to provide an LED light bulb for growing plants, which can selectively use colors of light emitted from LEDs in accordance with the illuminance of actual external light. A substrate (1) on which a plurality of LED chips (10) for providing growing light to plants are arranged and a lighting circuit (20) for lighting the plurality of LED chips (10) are provided in a base (2). A globe 3 is attached, a base 4 electrically connected to a lighting circuit 20 is attached to the rear, and a plurality of LED chips 10 includes a plurality of red LEDs 11 for irradiating a red LED and a plurality of LEDs for irradiating a white LED. A light inlet 30 for taking in external light, a sensor 31 for detecting the illuminance of the external light, and a plurality of red LEDs 11 when the illuminance detected by the sensor 31 exceeds a first predetermined value. Switching means 4 for turning off the plurality of white light-emitting LEDs 12 and turning off the plurality of red LEDs 11 and turning on the plurality of white light-emitting LEDs 12 when the number of white light-emitting LEDs 12 becomes equal to or less than a first predetermined value. Equipped with a. [Selection diagram] Fig. 1【課題】現実の外光の照度に対応してＬＥＤから照射される光の色を使い分けすることのできる植物育成用ＬＥＤ電球を提供する。【解決手段】植物に育成光を提供する複数のＬＥＤチップ１０が配置された基板１と、複数のＬＥＤチップ１０を点灯させる点灯回路２０が基体部２内に設けられ、基体部２の前方にはグローブ３が取付けられ、後方には点灯回路２０と電気的に接続された口金４が取付けられ、複数のＬＥＤチップ１０は、赤色ＬＥＤを照射する複数の赤色ＬＥＤ１１と、白色ＬＥＤを照射する複数の白色発光用ＬＥＤ１２を有し、外光を取り入れる光取入口３０と、外光の照度を検知するセンサー３１と、センサー３１の検知した照度が第一所定値を超えるときには複数の赤色ＬＥＤ１１を点灯しかつ複数の白色発光用ＬＥＤ１２を消灯し、第一所定値以下になると複数の赤色ＬＥＤ１１を消灯しかつ複数の白色発光用ＬＥＤ１２を点灯する切替え手段４０を備える。【選択図】図１
