On 20.1.2015 on the Great British Garden Revival Joe Swift showed his favourite range of plants available for Bog Gardens.
The important detail to decide on is whether your bog garden is moist or waterlogged. Each needs a different type of plant selection. Moist plants need a drained but moist soil and a muddy, waterlogged bog needs plants that will be happy sitting with their roots in water for part of the winter.
See this Tips and Advice page To Build a Bog Garden for yourself.