Based on the idea that modification of light quality could realize the modulation of morphogenesis and growth rate of plants, we fabricate a near ultraviolet (NUV)-green to red spectral converting BaY₂S₄:Eu²⁺, Er³⁺ phosphor by a solid state reaction route. We herein investigated the crystal structure and photoluminescence properties of the compounds in details. The incorporation of Eu²⁺ ions does not only enhance the red emission of Er³⁺ tenfold, but also broadens the absorption region of phosphor. Photoluminescence and decay curves confirm the energy transfer from the host lattices and Eu²⁺ ions to Er³⁺ ions. The optimized compositions have strong absorption in the NUV-green region and show intense luminescence at 600 and 663 nm, which matches well with the absorption spectrum (red region) of chlorophyll a. On the basis of the experiment results, a possible luminescent mechanism for the red-emitting BaY₂S₄:Eu²⁺, Er³⁺ phosphor is proposed. We believe this new NUV-green to red spectral converter may open a new route to the design of advanced phosphors for agricultural applications.