The effect of competition on five Norway spruce(Picea abies(L.) Karst.) clones of different provenances growing monoclonally (intragenotypic competition) and in intimate mixtures (intergenotypic competition) at close spacing were studied until the age of five years. In height, root collar diameter, dry weight, and mortality rate, clones reacted differently to the treatments, showing significant inherent competitive differences. A positive competitive reaction between certain clones can raise total increment by overcom‐pensation and can reduce risks by maintaining genetic diversity until harvest.