The invention relates to a fluorescent lamp for the illumination of plants, having a tubular discharge vessel, two electrodes which are fused in a gastight manner into the ends of the discharge vessel, a fill comprising at least a noble gas and mercury, and a phosphor coating on the inner wall of the vessel, the phosphor coating at least including a europium-doped barium magnesium aluminate phosphor of the BaMgAl.sub.10O.sub.17:Eu type and a cerium- and terbium-doped gadolinium zinc magnesium pentaborate phosphor of the Gd(Zn,Mg)B.sub.5O.sub.10:Ce,Mn type, and, to generate light with as high a light yield as possible and with a color temperature of between 4000 and 5500 K, the phosphor coating additionally includes an antimony- and manganese-doped calcium halophosphate phosphor of the Ca.sub.10(PO.sub.4).sub.6(F,Cl).sub.2:Sb,Mn type. This novel phosphor coating allows the light yield to be increased by 10% if the proportion by weight of the individual phosphors is optimized.