The present invention relates to a process for line production of plant growth medium bags comprising the steps of: a) continuously folding the free end of a continuous length of water and air permeable sheet material, preferably supplied on a reel, into a tube around and beyond a free end of a growth medium feeding tube； b) forming a first sealing in the tube by engaging and flattening the opposed walls of the open end of the tube, and advancing the continuous length of water and air permeable sheet material a predefined distance； c) through the free end of the growth medium feeding tube, filling the tube with a measured amount of growth medium； d) forming a second sealing in the tube at a position above the growth medium by engaging and flattening the opposed walls of the open end of the tube to form a first growth medium bag, or a compartment in a first growth medium bag with multiple compartments, and advancing the continuous length of water and air permeable sheet material a predefined distance； e) optionally, repeating the steps c)-d) to form a series of interconnected growth medium bags； and f) separating one or a group of interconnected growth medium bags from the series of interconnected growth medium bags.
