Practicality might dictate limiting plant species to the most hardy, commonly found, and easily managed. However, demonstrational research has found that cattails and reed canary grass have proven to be low cost, easy to establish, low maintenance, and tolerant of a wide range of climatic and contamination conditions. This makes control of water levels less critical for vegetation. The success of this method depends greatly on the source of the establishment water and the proximity of the constructed wetland to naturally occurring wetlands or other aquatic vegetation. Water used to establish a wetland that comes from a stream or pond would evolve more quickly than water from a spring.
Natural evolution is the least expensive method.
However, most situations do not lend themselves to this method because of the number of years to achieve sufficient vegetative growth. Mechanical seeding success rates vary because of climatic conditions, water levels, etc. Most plants will not establish from seed in standing water, but do need constantly wet soils. Reed canary grass will establish easily from seed with proper seedbed preparation and a shallow seeding with good seed-soil contact. Reed canary grass makes good cover for berm areas as well as marsh areas of shallow water within the wetland.