The invention provides a plant growth system comprising growing substrates (110； 206； 306) as well as plants (P) of which the roots (R) grow in the growing substrate, a number of holding bodies (100； 202； 301) each having a bottom (101； 224； 324) and at least one bottom spacer (104, 105； 9b； 309b), the at least one bottom spacer at the upper side thereof supporting a growing substrate thereon such that a distance is maintained between the bottom and the growing substrate, - irrigation means (331) for supplying water to the roots of the plants, - drainage means having a drainage opening (241； 341) in the bottom as well as a common drainage which is in communication with each of the drainage openings for allowing water supplied by the irrigation means to the plants to drain via the drainage opening to the common drainage, - a water permeable root barrier (123； 205； 305) for each holding body wherein the at least one root barrier is positioned below the upper side of the at least one bottom spacer, upstream of the common drainage for allowing passing of water throught the root barrier to the common drainage but preventing the roots from penetrating throught the root barrier in the common drainage.
