The studies conducted in 2010-2011 at the Research Institute of Horticulture in Skierniewice were aimed to compare the effectiveness of different weeds management methods useful in organic production of celeriac. The effectiveness of such methods as mechanical treatments, the usage of mulches (polypropylene and biodegradable films), the usage of polypropylene mulch with biostimulator AlgaminoPlant and hand weeded was compared. The weeds control, number and biomass of weeds and secondary weed infestation were determined during the experiments. The plants height and the yield of celeriac were measured also and additionally the ecophysiological indices such as relative variable chlorophyll fluorescence and chlorophyll content in the leaves. The best results of weed control were achieved in celeriac weeded by hand and grown in the soil mulched with used materials which was resulted in higher yields of celeriac. Mechanical treatments were control weeds well but the effects were short-lived and the yields of celeriac were lower than in the check. The chlorophyll content in the leaves before harvest was slightly lower in plants grown in mulches. The relative variable chlorophyll fluorescence was the highest throughout the growing season in mechanical weeded celeriac plants.