The main aim of the study conducted in the years 2007–2008 was to evaluate the effect of increasing levels of N, P, K and Mg nutrition on growth of lacy tree philodendron (Philodendron bipinnatifidum Schott et Endl.) grown in peat moss substrate for cut leaves to be used as floral green. Analyses were conducted for five increasing macroelement levels in the substrate, while maintaining a constant quantitative ratio of N : P : K : Mg = 1.0 : 0.75 : 1.25 : 0.75. On the basis of chemical analyses the constant nutrient levels were provided in the substrate, amounting to (in mg·dm^-3): L-1: N 100, P 75, K 125, Mg 75; L-2: N 150, P 112, K 187, Mg 112; L-3: N 200, P 150, K 250, Mg 150; L-4: N 250, P 187, K 312, Mg 187 and L-5: N 300, P 225, K 375, Mg 225. At all nutrition levels microelement contents were identical, amounting to (in mg·dm^-3): Fe 75.0, Mn 25.0, Zn 20.0, Cu 10.0, B 1.5 and Mo 2.0. Optimal yield of fresh and dry mass of aboveground parts of plants, as well as the number and length of leaves, width of leaf blades, length of petioles and leaf colour intensity was on the level of L-4 containing (in mg·dm^-3): N 250, P 187, K 312, Mg 187; L-5: N 300, P 225, K 375, Mg 225, Fe 75.0, Mn 25.0, Zn 20.0, Cu 10.0, B 1.5, Mo 2.0.

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