A randomised blocks experiment was set up in 2003 at the Felin Experimental Farm of the University of Life Sciences in Lublin. In the period of 2004-2011 a study was conducted on the effect of nitrogen (100 and 200 kg ha^-1 N) and phosphorus (39 and 52 kg ha^-1 P) fertilisation on the level of yields of biomass of Virginia Fanpetals. The higher doses of the nutrients caused a significant increase of the yields of biomass and on the shoot density of Virginia Fanpetals. Longer shoots were observed after the application of the higher level of nitrogen fertilisation. The greatest differences in the level of yields were noted among the years of cultivation. The lowest yield of biomass was obtained in the second (2004), and twice as much in the fifth (2007) and eighth (2010) years of cultivation (7.06 and 14.34 and 14.48 t ha^-1 d.m., respectively).