Pond plants are essential for maintaining a balanced aquatic ecosystem in any water garden. They provide numerous benefits, including water filtration, oxygenation, habitat for wildlife, and aesthetic beauty. Understanding the different types of pond plants and their roles can help you create a thriving, visually appealing pond. Proper planting, regular maintenance, and careful consideration of plant selection will help your pond remain a thriving and tranquil habitat for years to come.

Benefits of Pond Plants

Pond plants are not just ornamental; they play several critical roles in maintaining a healthy pond ecosystem:

• Water Filtration: Plants like submerged species absorb excess nutrients, reducing the risk of algae blooms and keeping the water clear.
• Oxygenation: Submerged plants produce oxygen during photosynthesis, which is essential for the survival of fish and other aquatic organisms.
• Habitat and Shelter: Pond plants provide shelter and breeding grounds for fish, amphibians, and beneficial insects, contributing to a balanced ecosystem.
• Erosion Control: Marginal plants help stabilize the edges of the pond, preventing soil erosion and maintaining the integrity of the pond’s structure.
• Aesthetic Appeal: With their diverse shapes, colors, and sizes, pond plants enhance the visual appeal of any water garden, creating a serene and picturesque environment.

Types of Pond Plants

Submerged Plants

Submerged plants, often referred to as oxygenators among pond keepers, grow entirely underwater. They are vital for maintaining water quality by producing oxygen, which is crucial for fish and other aquatic life, and by absorbing nutrients that could otherwise lead to excessive algae growth. Examples of submerged plants:

Hornwort (Ceratophyllum demersum)

This is a popular oxygenator that helps keep the water clear and free of excess nutrients, and it is commonly kept in both ponds and aquariums. Hornwort has allelopathic capacity and excretes certain substances that will inhibit the growth of phytoplankton and blue-green algae (cyanobacteria).

Hornwort is a submerged, free-floating aquatic plant, but can attach itself to objects in the pond. Once you have started growing hornwort, you can propagated it by cutting. Newly hatched fish fry and other small animals can find good shelter among the filamentous hornwort leaves.

Hornwort is native to all continents except Antarctica. In the wild, it is chiefly found in ponds, lakes and slow-moving streams where there is plenty of nutrients. This plant can handle winters. In Euroasia, it occurs as far as 66 degree latitude in Norway and Siberia (i.e. roughly 61 km south of the Arctic Circle.) In North America, it is found throughout the entire United States and in large parts of Canada. Hornwort can also live in warm climates and have for instance been reported from Ghana, Burkina Faso, and Vietnam.

Important:

• Landplants belonging to the division Anthocerotophyta are also called hornwort, so be careful when you make your purchase.
• Many products designed to kill snails in ponds will make the hornwort lose its leaves. The stem might survive, but it will take weeks before the leaves have grown back.

Anacharis / Canadian pondweed (Elodea canadensis)
A fast-growing plant that provides excellent cover for fish and helps maintain a balanced ecosystem. It has its first roots in the mud at the bottom, but will then produce adventitious roots at intervals along the stem as it grows. These roots can hang free in the water or grow down and anchor themselves at the bottom. If conditions are favorable, the anacharis in your pond can become 3 metres long or more.

The ideal summer water temperature for anacharis is 10-25 degrees C. It wants moderate-to-bright sun. You can propagate it using cuttings.

Important:

• E. canadensis is native to North America and is considered a problematic invasive species in many other parts of the world, including Euroasia, Africa, and Oceania.
• E. canadensis can grow very fast and choke shallow ponds unless you prune it.

Brazilian waterweed (Egeria densa)
Commonly used in aquariums and ponds, it helps control algae by competing for nutrients.

This plant is native to South America, where is is found in parts of Brazil, Chile, Uruguya, and Argentina. It can survive in both tropical and warm temperate climates.

Brazilian waterweed grows in water up to 4 metres deep and produce trailing stems. There will be roots at intervals along the stem. It can adapt to various light levels, including very shaded environments.

Brazilian waterweed plants available commercially are usually male clones and can be easily propagated by cuttings.

Some studies indicate that E. densa secretes antibiotic substances which may hamper the growth of cyanobacteria (blue-green algae).

Important:

• E. densa is considered a problematic invasive species in some parts of the world. It prefers stable temperatures in the 16-28 degree C range and is less likely to become problematic outside that range.
• The stems can cover the surface of the pond and create a thick canopy that blocks the light from reaching plants below it. This can reduce the amount of phytoplankton in a pond, but is not always desired by pond keepers.

Floating Plants

Floating plants drift on the water’s surface, with their roots hanging down into the water. These plants are effective at shading the pond, reducing sunlight penetration, and thus limiting algae growth. They also provide shelter for fish and other aquatic organisms. Popular floating plants include:

• Water Hyacinth (Eichhornia crassipes): Known for its beautiful purple flowers, water hyacinth is a fast-growing plant that can cover the pond surface quickly.
• Water Lettuce (Pistia stratiotes): Resembling a head of lettuce, this plant floats freely on the water’s surface and helps shade the pond.
• Duckweed (Lemna minor): One of the smallest and fastest-growing pond plants, duckweed forms a dense mat on the water surface, providing excellent cover for fish.

Water Lilies and Lotus

Water lilies and lotus are iconic pond plants that anchor their roots in the pond’s bottom while their leaves and flowers float on the surface. These plants are not only beautiful but also provide shade, cooling the water and reducing algae growth. Examples:

• Water Lily (Nymphaea spp.): Available in various colors, water lilies are known for their large, round leaves and stunning flowers.
• Lotus (Nelumbo nucifera): The lotus is revered for its large, fragrant flowers and is often associated with cultural and spiritual significance in many parts of the world.

Marginal Plants

Marginal plants grow in shallow water along the pond’s edge, with their roots submerged and foliage above water. These plants are not only decorative but also play a crucial role in stabilizing the pond’s edges and providing habitat for various aquatic creatures. Popular marginal plants include:

• Cattails (Typha spp.): Known for their tall, reed-like appearance, cattails are common in many ponds and wetlands.
• Iris (Iris spp.): Irises add vibrant colors with their striking flowers and thrive in the moist conditions of pond margins.
• Marsh Marigold (Caltha palustris): This plant produces bright yellow flowers in spring and is excellent for adding color to the pond edge.

Planting and Care

Planting

When adding plants to your pond, consider their specific growth requirements and water depth preferences. Marginal plants should be placed in shallow areas near the pond’s edge, while submerged plants can be placed in deeper sections. Use planting baskets or aquatic soil to anchor the plants and prevent them from spreading uncontrollably.

Water lilies and lotus should be planted in containers and then submerged at the appropriate depth. Floating plants, on the other hand, do not require planting; they can simply be placed on the water’s surface.

Maintenance

Regular maintenance is essential to keep your pond healthy and balanced:

• Trimming and Pruning: Overgrown plants should be trimmed regularly to prevent them from taking over the pond.
• Dead Leaf Removal: Remove dead or decaying leaves to prevent them from sinking to the bottom and decomposing, which can lead to poor water quality.
• Thinning: Floating plants, in particular, may need to be thinned out periodically to ensure they don’t cover the entire surface, which can reduce oxygen levels and harm the pond’s ecosystem.
• Winter Care: Some plants may require special care during the winter months, especially in colder climates. For instance, tropical plants like water hyacinth should be removed before the first frost and either composted or brought indoors.

Choosing Pond Plants

Here are a few examples of factors that can be good to consider when selecting plants for your pond.

• Climate: Ensure the plants you choose are suitable for your climate. Tropical plants may not survive in colder regions without special care.
• Pond Size: Consider the size of your pond when selecting plants. Larger ponds can accommodate more extensive or aggressive species, while smaller ponds may require more careful selection to avoid overcrowding.
• Wildlife: Think about the types of wildlife you want to attract or support in your pond. For instance, certain plants are better suited for providing shelter to fish, while others may attract specific types of insects or amphibians.

Final Thoughts

Pond plants are essential for creating a healthy, balanced, and beautiful aquatic environment. By selecting the right combination of marginal, submerged, floating plants, and water lilies or lotus, you can enhance both the ecological health and aesthetic appeal of your pond. Whether you’re a seasoned gardener or a novice pond owner, incorporating a variety of pond plants is key to achieving a vibrant and sustainable water garden