Abstract: The invention provides a modular wall system [10] which is adapted for supporting a vertical garden. The modular wall system [10] comprises a supporting wall [12] comprising first liquid guiding means [16] for guiding water, liquid nutrient feedstock and the like in the wall [12], and first engaging means [18] for engaging a plant container [14] in various different positions on the supporting wall [12]. The modular wall system [10] also comprises at least one plant container [14] for housing plant material, wherein the plant container [14] comprises second engaging means [32] for releasably engaging the supporting wall [12], and second liquid guiding means [34, 36] extending from the plant container [14] into the first liquid guiding means [16] and dimensioned for guiding liquid from the first liquid guiding means [16] in the supporting wall [12] into the plant container [14].