The invention provides a self-watering system for a potted plant comprising a liquid container and an insert with an in use position against the potted plant pointing upper part, which extends at least partially through an opening in the pot bottom. The invention is primarily intended for use in watering of potted plants ready for sale from e.g. horticultural greenhouses, but can obviously also be used for both the subsequent watering during the rest of the plant's life from end-users and for watering during the cultivation of a potted plant.