Tips on adding aquatic plants to your garden pond

A well maintained pond is an amazing addition to any garden and planting aquatic plants adds greater aesthetic appeal. Plants, in addition to their beauty, will also function in controlling algae levels and help to oxygenate the water.

The Perfect Pond Planting Plan: What to Plant, Where to Plant It and When

If you are building a garden pond, planting aquatic plants is one of the most important factors in creating a healthy, balanced ecosystem. Many first-time pond owners focus on fish and filtration, but plants provide natural water quality benefits, wildlife habitats, shade, and visual appeal.

When buying plants it is best to visit a reputable garden or aquatic centre whose expertise include that of pond plants. Another source is from a keen pond keeper who is subdividing plants to control growth and is willing to share rather than discard.

To avoid introducing unwanted organisms into your pond, make sure you always buy water plants that look healthy (check above and underneath the leaves for any signs of plant disease) and are growing in clean, algae free ponds.

Choose different types of aquatic plants to add diversity across your pond including oxygenators, which will increase the amount of oxygen in the water thereby helping to keep a healthy ecosystem.

Include Several Types of Aquatic Plants

A successful pond usually contains a mix of:

• Oxygenating plants - Grow underwater and help absorb nutrients while releasing oxygen. Examples include Hornwort and Water Milfoil. Aim for at least one bunch per square metre of pond surface.
• Marginal plants - Grow around the pond edges in shallow water. Examples include Yellow Flag Iris, Marsh Marigold and Water Mint. These varieties soften pond edges and provide shelter for wildlife.
• Floating-leaved plants - These provide shade and reduce algae growth. Examples include the Water Lily and Frogbit.
• Deep water plants - Occupy deeper areas and add structure to the pond. Examples include Water Hawthorn and Water Lily.

The best time to plant is spring or early summer:

• Plants establish before algae becomes problematic.
• Root systems develop throughout the growing season.
• Wildlife quickly begins using the pond.

For a newly built pond, it's often advisable to plant as soon as the pond has been filled and water quality has stabilised.

When transporting aquatic plants home to your pond, it is best to avoid them drying out by keeping them in a plastic bag or a container.

Planting aquatic plants above a pond liner 

• Plant into a flat-based pot or a plant basket, both of which can be bought at most big garden canters.
  
• Fill the pot with either soil, washed rocks or gravel sand.
• Place the plant directly into the gravel sand or place a rock over the roots of the plant to hold the plant and pot down under the water.
  
• Cover around 50–70% of the pond volume with plants.
• Allow floating leaves to cover approximately 40–60% of the water surface during summer. This provides shade while maintaining open water for wildlife and viewing.
• Allow for future growth. Most aquatic plants become much larger after one or two growing seasons.
• When planting leave space between baskets.
• Avoid cramming marginal shelves.
• Expect lilies to spread significantly.

A simple planting formula for beginners for a typical 5m × 4m wildlife or ornamental pond:

• 1–2 water lilies.
• 6–10 marginal plants.
• 4–6 oxygenating plant bunches.
• A few floating plants (where permitted).
• Some native wildlife plants around the pond edge.

This creates a good balance of filtration, shade, wildlife value, and appearance without overcrowding the pond.

In summary

Aquatic plants supply not only oxygen to water as well as shelter and food. If you are introducing plants to a pond housing fish it is advisable to do research into the types of plants you buy before planting, as there are varieties that are toxic to fish. 

A further advantage of pond plants is that they are a more natural way of filtering your pond. This is a great idea for a larger ponds and the health of your fish.

Garden ponds can be a welcome addition to any outdoor space. Choosing your design, location, features, materials including pond liners and pond plants wisely will create a pond that fills their space with the exact ambiance that you desire.