Everything You Need to Know

A water garden seamlessly blends aquatic plants and animals with a habitable water environment. Learn how to build a water garden—a serene focal point for your yard that’s also teeming with life.

Benefits of a Water Garden

A water garden is beautiful and functional at the same time, since it:

• Conserves water: Collected rainwater can be diverted to a water garden.
• Improves appearance: A water garden adds interest and beauty to a yard.
• Builds a natural habitat: Aquatic flowers, plants, and animals support each other in this mutually beneficial ecosystem.
• Increases property value: A well-designed built-in water garden adds resale value to a home.

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Main Features

A water garden typically consists of four main elements: a water feature, clean water, plants, and animals.

• Water feature: The water feature can be a pond, waterfall, bog, or stream.
• Water: The water in a water garden is ordinary water from a hose or clean rainwater collected in rain barrels. 
• Plants: A complete water garden contains a range of floating, bog, submerged, and deep-water plants.
• Animals: Fish, snails, and frogs are a few of the animals found in water gardens.

Types of Water Gardens

A built-in water garden looks like a real pond, but a container water garden is cheaper and easier to build.

Built-In Water Garden

A built-in water garden mimics the look of a natural pond. An artificial garden pond can be lined with plastic, concrete, or granular bentonite clay.

A built-in water garden can look like a natural water feature and merge with the rest of the yard. It can also be as deep as you need, allowing for the multiple layers needed to build a comprehensive water garden.

A built-in water garden takes the longest to build and, in some cases, may not be buildable if there are buried obstructions. It’s also one of the more expensive water gardens to build.

Container Water Garden

A container water garden consists of a collection of containers of various sizes, such as barrels and tubs, kept fairly close together. 

A container water garden is the most flexible type, as it can be easily arranged and rearranged. It can be installed on weight-bearing decks or patios.

Above-Ground Water Garden

An above-ground or raised water garden is built from the ground upward, little or no digging involved. This helps the garden avoid possible complications with buried wires and pipes. 

Stock tanks can be used to make an above-ground water garden. Or the water garden can be custom-built with masonry and liner materials. 

Water Garden Plants

Plants make a water garden a garden, not simply a pond. Depending on the type of water garden, include all four types of plants—floating, bog, submerged, and deep water—or as many as you need.

Floating Plants

Floating plants float on the water’s surface, using the water itself as its nutrient base. 

Floating plants are a natural shade, so they help to control algae bloom. By drawing nitrogen from the water, floating plants further help limit algae growth. Examples of floating water plants include:

• Azolla
• Duckweed
• Fairy moss
• Water hyacinth
• Water lettuce

Bog or Shallow Marginal Plants

A bog, in terms of a water garden, is an area of water between 1 and 4 inches deep. Bogs can be found in all water gardens—in-ground, above-ground, and container.

Bog plants add color and texture to water gardens. Examples of bog plants: 

• Cattails
• Parrot’s feather
• Water pickerel
• Water poppy

Submerged or Oxygenator Plants

Submerged plants float in the water, just below the surface. 

Submerged plants or oxygenators act as sponges for excess nutrients in the water, so they help to limit algae growth. Examples of submerged plants include:

• Anacharis
• Cabomba
• Hornwort
• Vallisneria

Deep Water Plants

Deep-water plants in a water garden need at least 4 to 10 inches of water over them.

This doesn’t mean that all the plants are hidden. Water lilies and lotus are well-known deep-water plants that display their leaves or spikes on the surface.

Deep water plants keep ponds cool, and they shade fish and other aquatic creatures. Examples of deep water plants include:

Water Garden Animals

Fish, namely koi, are the most common aquatic animal in water gardens. 

Fish must be fed regularly, but only as much food as they need to avoid excess food decomposing on the surface of the water. 

While fish add motion and life to a water garden—and for many owners, they are the centerpiece—they can damage water plants. They eat leaves and occasionally uproot deep-water plants when they move around or lay eggs. 

Turtles and snails sometimes find their own way to the water garden, or they can be artificially introduced.

Where to Locate the Water Garden

Locate the water garden near enough to the home so that you can enjoy it and easily maintain it, but not so close that water overflow floods the foundation or basement.

Most water gardens need at least six to eight hours of sunlight daily. However, excessive sunlight can cause algae blooms.

Avoid placing built-in water gardens above or near in-ground power lines, water mains, or electrical conduits leading to lights or detached accessory buildings. Have the site checked by a utilities locating service.

Container and above ground water gardens are safest when placed on the ground. But if you locate them on a structure such as a deck or balcony, have a contractor or structural engineer assess the structure’s weight-bearing properties.

How to Build a Water Garden

Building an in-ground water garden starts by building a pond and then adding plants and animals to it.

1. Create the shape: Define the water garden’s general shape with a hose or rope.
2. Check for utilities: Call the utility locating service to check for buried lines.
3. Dig the pond: Dig the pond to the desired depth, usually 18 to 36 inches, by hand or with a rented digger.
4. Smooth the pond: Use a flat-bladed shovel to sculpt the inside of the pond. For deep ponds, terrace the slope downward rather than building steep inclines.
5. Add the liner: Unroll and place the liner or pack the pond with granular bentonite clay.
6. Cover the edges: Place flat stones like flagstones on the edge of the liner to cover it.
7. Install the filter and pump: Install the water filter and pump and plug them into a GFCI outlet.
8. Fill with water: Turn on the garden hose to fill the pond.
9. Add water plants: After the water reaches ambient temperature, add lilies, duckweed, or water poppies.
10. Introduce animals: After checking the water quality, add fish such as koi, pond snails, or turtles.

Maintenance

Water gardens are relatively high maintenance because weeds, algae, and other unwanted growth need to be kept in check. The water quality needs to be assessed, and if necessary, the water changed out.

• Limit algae by reducing excess nutrients in the water.
• Change the water if algae growth is severe.
• Weed in and around the water garden.
• Watch for predators.
• Before fall, cover the water garden with netting to keep leaves out.
• Shut down the pump and filter before winter.
• Clean the water garden in early spring.

Water Garden Troubleshooting