A compressed growing medium or mulch fiber opener comprising at least one set of adjacent rotating members, the rotating members having a surface and including at least one wire wound around at least a portion of the surface, wherein the wire includes a plurality of projections engaging compressed or partially opened growing medium or mulch fiber, and wherein a distance between the adjacent rotating members is sufficiently small to create at least one pinch point between the adjacent rotating members, the adjacent rotating members separating the fibers as the fibers pass through the at least one pinch point so that the density of the fiber is lowered by at least 50-95%.