Most pre-formed pond liners include a shelf for pots of marginal plants. This is because some plants prefer to be only just submerged rather than being at the bottom of a pond.

There are designs which incorporate a marsh margin; ideal for creating a pond with a natural-looking edge to it instead of paving. The marsh margin consists of a narrow channel around the edge of the liner. The margin retains soil or pebbles and stays wet because the retaining ridge between the pool and the channel is not continuous.