A plant spike light, including: a rod body, extending toward an axial direction, the rod body including an insertion portion inserting into a base portion； a light body, including at least one light unit, a plant growth sensor and a processor, the at least one light unit, the plant growth sensor respectively electronically connected with the processor, the light unit irradiating toward the base portion； a lifting mechanism, including a first lifting unit disposed on the rod body and a second lifting unit disposed on the light body, the first lifting unit or the second lifting unit being drivable by a power source； wherein when the processor determines that a plant height signal which is detected by the plant growth sensor and a predetermined height information are different, the power source is activated. A spike light assembly includes a plurality of plant spike lights mentioned above.本發明關於一種植物用插燈，其包括：一桿體，其朝一軸向延伸，該桿體包括一供插設於一基部之插設部；一燈體，包括至少一發光單元、一植物生長感測器及一處理器，該至少一發光單元、該植物生長感測器分別電性連接該處理器，該發光單元供朝該基部方向照射；一升降機構，其包括一設於該桿體之第一升降單元及一設於該燈體之第二升降單元，該第一升降單元或該第二升降單元可被一動力源驅動；其中，該處理器判斷該植物生長感測器之植物高度訊號與一預設高度資訊不同時，啟動該動力源。本發明另關於一種包括複數前述植物用插燈之植物用插燈組。
