Difficulties frequently arise in connection with the securing and mounting of plants or flowers in a pot. The invention relates to a plant holding device (10) which is designed to couple to a plant container (20), comprising at least one opening (11) which can be accessed from above for a plant stake (3, 30). The plant holding device has a support groove (13) which is open towards the bottom and which is designed to couple onto an edge of the plant container (22) from above, said support groove being arranged laterally of the opening in the radial direction and extending in the circumferential direction. In this manner, the work of a florist is simplified, and diverse applications are made possible. The invention additionally relates to a plant holding kit (40) comprising at least one such plant holding device, at least one plant stake (30), and optionally a plant container as well. The invention also relates to a method for providing a plant container (20) with at least one such plant holding device (10).