The effect of different ammonium NH₄⁺ and nitrate NO₃⁻ ratios (4:1, 2:1, 1:1, 1:2, 1:4, 1:6) on organogenesis of ‘We˛gierka Zwykła’ leaf explants cultivated on media with nitrogen levels equalling full- or half-MS was investigated. On media with total nitrogen equal to ½ MS, explant regeneration increased significantly and was highest on media with 1:2 or 1:4 NH₄⁺ :NO₃⁻ ratio. An excess of ammonium versus nitrate ions had a negative effect on both regeneration and biomass. Addition of potassium to the medium increased the fresh weight of explants and the number of adventitious buds.