Directory of Pond Plants
These plants are not renowned for their flowers, but they give the pond a more natural feel and are important for the well-being of the fish. They spread to form a dense mass, protecting the fish from predators, especially birds, and also from sunburn, in addition to curbing algal growth. Furthermore, they provide spawning sites and food for some species of fish. Floating plants are easy to establish—simply let them drift on the surface until they find a suitable position—and they develop much faster in a new pond than other types of plants, such as marginals and water lilies. Some popular varieties originate from warm climates and are not hardy in temperate areas. They should be brought inside to protect them from winter frosts.
Carolina Fairy Moss (Azolla cristata)
- ORIGINS Occurs naturally from the US to South America, but now naturalized in parts of Europe.
- SIZE Leaves each measure about 1⁄2 in (1.5 cm) long.
- WATER This plant needs clear water in order to thrive. Hardy to 0°F (–18°C).
- PROPAGATION Reproduces asexually, so simply divide up a clump, preferably in spring.
This floating green fern spreads rapidly over the pond’s surface, so its growth may have to be kept in check. Fairy Moss becomes more reddish during summer. It dies back in fall and sinks to the bottom but resurfaces again in spring. In temperate areas, overwinter some of the fern indoors in an aquarium, or in a plastic container of water on a windowsill; otherwise, the entire stock may be destroyed by very cold weather.
Water Chestnut (Trapa natans)
- ORIGINS: A native European species, it is now naturalized in parts of the US and Australia.
- SIZE: Rosettes can reach up to 30 in (75 cm) in diameter.
- WATER: Prefers still or slow-moving water. Min. temp. 32°F (0°C). This annual plant dies off before winter.
- PROPAGATION: Grown easily from its chestnutlike seeds, which can be set in pots of aquatic soil.
This annual plant has serrated edges on its green, purple-centered leaves, which grow in the form of a rosette. The inconspicuous white flowers are followed by large black fruits, which can be left to overwinter in the pond. Otherwise, store them indoors in damp sphagnum moss. They must not dry out if they are to germinate in the spring.
Common Water Hyacinth (Eichhornia crassipes)
- ORIGINS: South America, but now naturalized in many other areas, including Africa. Banned in some places.
- SIZE: Leaves 4 in (10 cm) long; flower spikes 6 in (15 cm).
- WATER: Prefers calm water, so keep away from fountains. Hardy to 32°F (0°C).
- PROPAGATION: Split small plantlets off the sides of existing clumps.
This plant gets its name from its mauve blooms, which resemble hyacinth flowers. Air trapped in the leaf bases provides buoyancy and enables the plants to float. Hidden beneath the surface are long, trailing roots that provide spawning sites for goldfish and protection for fry. Common Water Hyacinth spreads rapidly in warm climates and should never be released into natural waterways, where it can cause serious environmental and economic damage.
Duckweed (Lemna species)
- ORIGINS: Found throughout the world, in both temperate and tropical regions outside polar areas.
- SIZE: Tiny leaves measure about 1⁄3 in (0.8 cm) across.
- WATER: Grows well in any depth of water, but prefers relatively little movement. Hardy to –30°F (–34°C).
- PROPAGATION: Simply split off a few pieces from a mat, and these will soon start to replicate.
Duckweed is often accidentally introduced into a pond with other plants. Once present, it spreads rapidly, providing cover for fish and even food for some species. Scoop it out with a net if it threatens to form a suffocating mat over the entire pond. You can restrict its spread by using a fountain to create surface movement. Duckweed does not compete well with other floating plants or lilies.
Water Soldier (Stratiotes aloides)
- ORIGINS: Occurs naturally in parts of Europe and as far east as northwest Asia.
- SIZE: Can reach up to 20 in (50 cm) in height.
- WATER: Prefers hard water with little or no movement, and a sunny location. Hardy to –20°F (29°C).
- PROPAGATION: Detach winter buds, or remove young plantlets in spring.
This plant is seen only on the surface in summer, when it produces white flowers on short stems. Distinct male and female plants do occur, but Water Soldier usually reproduces by division, rather than by seeding. The calcium carbonate it absorbs from its hard-water surroundings causes it to sink to the bottom in winter, where it throws out side shoots called turions. These produce new plants in spring
Water Lettuce (Pistia stratiotes)
- ORIGINS: Originally from Florida and the Gulf Coast of the US; now present in warmer areas worldwide.
- SIZE: Can reach 6–12 in (15–30 cm) in height.
- WATER: Prefers still water and a sunny location. Minimum temperature 50°F (10°C).
- PROPAGATION: Separate young plantlets from large plants. Water lettuce may occasionally set seed.
The green, velvety leaves of Water Lettuce grow in the form of a rosette above the water’s surface, while its long, feathery roots, measuring up to 18 in (45 cm) long, provide valuable breeding sites and cover for fish. The small, whitish flowers are easily overlooked. Water Lettuce is sensitive to cold temperatures and so must be brought inside if it is to survive the winter in temperate areas.
Golden Club (Orontium aquaticum)
- ORIGINS: Occurs naturally in eastern parts of Canada and the US.
- SIZE: Spread is 24–30 in (60–75 cm).
- WATER: Start off in a shallow, sunny position; can later be moved to deeper water. Hardy to –10°F (–23°C).
- PROPAGATION: Divide mature plants in spring or fall, or sow seeds during summer.
The versatile Golden Club can be cultivated either as a floating plant or as a marginal in shallow water around the edge of the pond, where it will look particularly attractive against waterside irises and primulas in early summer. The appearance of Golden Club varies accordingly, with the lancelike leaves measuring about 18 in (45 cm) in the shallows but rarely exceeding 12 in (30 cm) when floating in deeper water. The leaves are mid-green above and often purplish beneath. Golden Club blooms from late spring to midsummer, producing unusual blooms that are white at the base and yellow toward their tips. Golden Club is hardy in temperate areas and capable of forming large clumps. Plant the rhizomes of Golden Club in deep containers, since this species develops a large root system. Do not allow plants to root by themselves, because it is difficult to move clumps successfully once they have become established.