A process for line production of plant growth medium pots or bags with a closed bottom end includes the steps of: i) continuously folding the free end of a continuous length of water and air permeable sheet material into a sheet material tube around and beyond a free end of a growth medium feeding tube; ii) forming a first sealing in the sheet material tube; iii) filling the sheet material tube with a measured amount of growth medium; iv) forming a second sealing in the sheet material tube; v) separating the part of the sheet material tube positioned downstream from the second sealing to form a first plant growth medium pot or bag with a closed end, repeating as needed to form a plurality of plant growth medium pots or bags.