The invention relates to an assembly in use forming a tray (1) for plant material, comprising a holder (2)； and at least one insert (3) which can be respectively placed in and removed from the holder, wherein the insert comprises at least one cell (4) defining a plant position. The or each cell comprises at least a wall (14) and a bottom (13) for accommodating content in the cell in use of the assembly. The at least one wall substantially encloses the plant position. The wall and/or bottom comprises an opening (10) through which access is provided to means for removing the content of the cell, such as a pusher or a ram, such as a pin, of an apparatus according to the invention. In a row, a sequence of cells, which can be interconnected, in such an insert defines a longitudinal direction of the insert. When the insert is taken out of the holder, at least the plant material from a neighbouring cell in the longitudinal direction cannot form an obstacle during removal of the substrate and/or the plant material from a desired or selected cell.
