The edges of artificially sealed ponds and wetlands often show an extremely sharp transition between a wet area within and a more or less dry area outside the lining material. It is recommended that plants are selected for zone 1 that look similar to wetland plants but are able to withstand periods of dryness. These can be lush looking grasses or forbs with wide leaves, for example species of the genera Miscanthus, Hemerocallis, Helianthus or droughtresistant Irises for sites rich in nutrients. On nutrient – poor sites, a possible bog or fen vegetation can be continued outside the sealing, for instance with small Allium, Carex, Sesleria, Briza or Anthericum species.
Zone 2—the wetland area
The margins of water bodies, periodically flooded zones, wet flushes, bogs and fens represent an untapped resource for the designer. Whereas water-body margins are usually planted with a very limited range of species, there is great scope to adapt and modify a whole range of vegetation types, including wet and damp meadow-based vegetation and wet woodland and shrub-based communities.
The main types of vegetation to be considered in this zone include carrs (wet woodland), tall herb communities, wet meadows and pastures, fens and straw-meadows, and raised bogs.