Aquatic and Marginal Plants

About Aquatic and Marginal Plants

Phoenix Amenity supplies a range of aquatic and marginal plants for pond, wetland and waterway planting projects, covering all four aquatic planting zones.

Prepare the ground before planting to reduce competition from existing weed growth. Cut back tall vegetation and treat weeds such as docks and nettles with a broad-spectrum herbicide suitable for use near water.

Aquatic plants fall into four planting zones: boggy plants, marginal plants, emergents and submergents (oxygenators). Choose species according to the zone, since planting depth, water level and whether the water is flowing or standing, as in rivers or ponds, all affect which plants will establish well.

Boggy plants

These species grow in waterlogged or seasonally wet ground rather than in the water itself. We recommend a planting density of 20 plants per Sq.M using small wildflower plugs (27cc).

Marginal plants

Marginal plants are planted at, or just above, the water’s edge, to a maximum depth of 350mm. We recommend a planting density of 8 plants per Sq.M using 7cm plugs. Some species prefer drier conditions, while others prefer the damp, boggy soil at the water’s edge.

Emergents

Emergent plants are planted in the water column to a depth of 0-500mm, and the roots grow deeper over time. If the area is likely to dry out and the overall depth is less than one metre, avoid aggressive emergent species such as typha (bulrush) and Phragmites (common reed). Emergents such as reeds and bulrush are valued for their photo-remediation capacity, though they can eventually dominate an area if left unmanaged. We recommend a planting density of 8 plants per Sq.M.

Submergents

This group includes floating plants such as water lilies and oxygenating plants such as pondweed. They are grown fully submerged or floating in the water column, and we recommend a planting density of one to four plants per Sq.M. Most oxygenating species are sold in leaded bunches that can be dropped straight into the water; others, such as bogbean, creep along the surface and can be planted as bare-root plants. Water lilies are sold in baskets and should be submerged to a depth of up to 1.5m, which allows the leaves to float on the surface.

Advantages and uses of aquatic plants

• Reedbeds for water treatment and habitat creation
• Improving water quality in lakes and ponds
• Improving biodiversity
• Bioengineering applications
• Habitat creation, including for protected species
• Fisheries
• Aesthetic planting
• SUDS (sustainable urban drainage systems)