The embodiments of the present invention relate to the cultivation-, packaging-, and shipping of plugs, containing a seed or seedling and a substrate. In particular, a holder (10) is contrived having one or multiple cavities (11) in which a plug can be placed, together with one or multiple removal slits (12). Furthermore, a packaging tray (30) is contrived, having engaging means (32) and a perforated foil, to be used in unison with a particular holder for shipping that particular holder to a retailer or a customer. The holder could be placeable in both a cultivation tray (80) and a packaging tray (30).