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Updated on October 19, 2023

Planning guide

Laying out a water garden

Building a water garden is a great way to bring new life to your backyard. Here are a few tips on how to turn your backyard into a sanctuary by incorporating a water garden into your landscape design.

Choosing your Garden Style

The overall design of your sanctuary will be a sum total of the different elements. Before you begin, consider which type of garden is more appealing to you.

The Two Main Types of Gardens

  • Formal design is when the shapes are regular, paths are straight, and patio stones and garden walls are well defined. In this type of design, the water garden can be square, rectangular or circular in shape. Manicure surrounding lawns and hedges, and perhaps add a soft fountain to your water garden.
  • Informal designs incorporate more free form and natural flowing elements. Paths are winding, plants are cascading, and brooks and waterfalls make an appearance. Opt for indigenous, hardier plants like ferns, sedges, eupatorium, rushes and blue flags. Let foliage remain relatively unkempt, growing together as borders between species become undefined.
  • Formal Garden
  • Informal Garden

Planning your water garden project

Before buying your material, it’s important to plan each step, from the location to the material you’ll use.

Location

Location is a crucial factor for a flourishing, low-maintenance water garden. Here are several things to consider when choosing your garden’s location:

  • Water gardens need at least 6 hours of full sun.
  • Do not choose the lowest area of your yard for a water garden. Runoff from lawn pesticides, driveway salt and fertilizers could pollute it.
  • Marshy areas are not a good location for liner ponds. The water may come up under the liner, creating a bulge.
  • Do not place your water garden near trees.
    • Roots are hard to dig through when installing the water garden.
    • Shade is not good, as plants will not flourish.
    • Fallen leaves dirty the water creating algae that could kill fish.


Size

A frequent misconception is that a smaller water garden is automatically easier to take care of than a larger one. This is not necessarily true. Sometimes it is easier to achieve a natural balance—and less algae problems—with a larger pond.

Shape

Whatever size you choose, try to keep the shape simple. A kidney shape gives a natural look and thus has become quite popular. Steer away from shapes with bays and narrow sections to avoid problems with circulation.

Depth

Most water gardens are designed with multiple “shelves” to accommodate a variety of water plants.

  • The first shelf—the marginal shelf—is typically 2" - 9" deep to house bog and marginal water plants.
  • The next shelf is often referred to as the Lily Shelf, ranging from 10"-16" deep for lilies
  • The remaining pond is termed the Deep Area and is usually deeper than 18". It is recommended that water gardens be a minimum of 24" deep to avoid algae problems. The quantity and size of fish may also be a determining factor in the depth of your water garden. 

Pro Tip

Always check with local building officials to see if there is a depth at which you need to fence around your water garden. Plan ahead to include this factor in your project layout and budget.

Understanding a water garden’s life cycle

The ideal scenario of a water garden is to achieve a natural ecological balance in a man-made structure. Your aim is to simulate how a small pond would work in nature. With the right balance, the following natural cycle will take place:

Fish, plants, water quality, depth and sunlight are all vital factors in achieving a proper balance, resulting in a flourishing water garden. Here are a few tips to make that happen.

Pumps and Filters

It is not necessary for you to have a pump and filtration system in order to maintain a clean, clear water garden.

  • Running water does not significantly reduce algae.
  • Use a pump if you want to incorporate a fountain, waterfall or other moving water element.
  • If you do not have the proper balance between fish and plants, you may need a pump and filter to achieve good water quality.

Algae

The higher water temperature in shallower ponds encourages algae growth.

  • An influx in nutrients in the water will result in green water. This can be the result of too many fish, overfeeding the fish or excessive decomposing vegetation. Add more plants, decrease the amount of fish, feed the fish less, or add a filtration system to clear up the water.
  • Replacing “algae” water with fresh water will only increase the algae by adding a fresh supply of nutrients.
  • It is best to treat algae blooms naturally rather than trying to combat it with chemicals. Chemicals may clear your water for a short time, but will quickly be needed again and again. They can also cause harm to good plants, as well as to your fish.

Fish

It is recommended that your water garden have at least one fish to eat the mosquito larvae that will attempt to breed in your water garden.

  • The general rule is to have a maximum of 1” of fish for every square foot of surface area in your pond because fish produce nutrients needed for algae to grow. Remember that little fish grow into big fish!
  • If you only have several fish in your water garden, they will feed on insects and some of the plants. If you have more fish, or wish to see them come up to the surface for viewing pleasure, use fish food that will be completely consumed by the fish in less than 5 minutes. You must remove any uneaten food or it will rot at the bottom of the pond, increasing algae growth.

Pro Tip

Calculating the best pump size for your water garden is an important step. You want to be certain that the pump can provide enough water circulation for your water garden. This will help with water quality for both your plants and fish. If you plan to add any water features, such as a fountain or waterfall, you will need to account for this above and beyond the initial pump size needed to move water around the pond.

The general guideline for calculating pump size is to be able to pump half of the pond’s volume every hour. If your water garden is 2,000 gallons, the appropriate pump would move 1,000 gallons of water per hour.

Choosing Aquatic Plants

To create a water garden is to reproduce a complex, magnificent, natural milieu in which plants and fish play not only an aesthetic role, but a functional one, too.

Aquatic plants have important roles in a water garden’s ecosystem:

  • They are essential in the pond's ecological balance. Without them, the water would not be a source of life:
    • They provide shade for the water, keeping it cool while reducing conditions for an algae bloom.
    • They oxygenate the water.
    • They purify and clarify the water.
    • They provide nourishment and shelter for microscopic life forms that nourish fish and serve other essential functions.
  • They hide telltale signs of the pond's artificiality (liner, pipes, light sources etc.).
  • At the very least, they complement mechanical filtration and aeration systems. More often, they replace them.

To obtain a healthy equilibrium in your water garden, we recommend using the aquatic plants in the following four groups in the ratios shown.

Type of Aquatic Plants
Floating
Submerged or Oxygenated
Emergent Vegetation
Water Lilies
Ratio
2 per 1.5 m2
4 per 1 m2
Variable as needed
1 per 2 m2
Function
  • Purify the water
  • Provide shade and conserve pond oxygen
  • Refuge for minnows
  • Very useful early on when young water lilies are beginning to grow.
  • Oxygenate the water
  • Purify the water
  • Feed the fish
  • Discontinuous pond shading
  • Purify the water via the bacterial colonies they support
  • Fill up a buffer-zone between the pond and garden flowerbeds
  • Home for minnows, frogs, toads and aquatic birds
  • Beautify and integrate your water garden
  • Provide shade and conserve water oxygen
  • Purify the water
  • Protect the fish
  • Beautify the pond with spectacular flowers
Description
These don't touch the bottom. They float freely on the water surface, moving about with the wind and waves. Most of them are tropical annuals.
These are essential in a water garden. They’re totally submerged, and their roots are either at the bottom or floating in the water.
The roots may be in the soil or in a pot. Most of the stems, leaves and flowers rise out of the water. This highly diversified group, which is also called ‘moist area plants’, include paludal plants that grow out of the water, swamp plants, which always have their feet wet, and littoral plants, which grow on land surrounding a body of water and appreciate damp soil but not standing water.
These are essential in a water garden, they are also called Floating Leaf plants. Roots are at the bottom or in pots placed at the bottom. Leaves float on the water surface, as do the emerging flowers.
Care
Do not need planting or fertilizing. Simply place them on the water.
Place in specially designed baskets at the bottom of the pond. The baskets make it easier to clean the water garden and maintain the plants. Can be given aquatic plant fertilizer.
Place emergent plants in a basket and paludal plants in pots in the shallow end (or shelf) of the pond. Aquatic plants in submerged baskets do best with soil specifically designed for them. Swamp and littoral plants should be placed at the water’s edge or just beyond it. Can be given aquatic plant fertilizer.
Place in specially designed baskets at the bottom of the pond. Lilies need annual fertilizing with a special fertilizer.
Type of Aquatic Plants
Floating
Submerged or Oxygenated
Emergent Vegetation
Water Lilies
Ratio
2 per 1.5 m2
4 per 1 m2
Variable as needed
1 per 2 m2
Function
  • Purify the water
  • Provide shade and conserve pond oxygen
  • Refuge for minnows
  • Very useful early on when young water lilies are beginning to grow.
  • Oxygenate the water
  • Purify the water
  • Feed the fish
  • Discontinuous pond shading
  • Purify the water via the bacterial colonies they support
  • Fill up a buffer-zone between the pond and garden flowerbeds
  • Home for minnows, frogs, toads and aquatic birds
  • Beautify and integrate your water garden
  • Provide shade and conserve water oxygen
  • Purify the water
  • Protect the fish
  • Beautify the pond with spectacular flowers
Description
These don't touch the bottom. They float freely on the water surface, moving about with the wind and waves. Most of them are tropical annuals.
These are essential in a water garden. They’re totally submerged, and their roots are either at the bottom or floating in the water.
The roots may be in the soil or in a pot. Most of the stems, leaves and flowers rise out of the water. This highly diversified group, which is also called ‘moist area plants’, include paludal plants that grow out of the water, swamp plants, which always have their feet wet, and littoral plants, which grow on land surrounding a body of water and appreciate damp soil but not standing water.
These are essential in a water garden, they are also called Floating Leaf plants. Roots are at the bottom or in pots placed at the bottom. Leaves float on the water surface, as do the emerging flowers.
Care
Do not need planting or fertilizing. Simply place them on the water.
Place in specially designed baskets at the bottom of the pond. The baskets make it easier to clean the water garden and maintain the plants. Can be given aquatic plant fertilizer.
Place emergent plants in a basket and paludal plants in pots in the shallow end (or shelf) of the pond. Aquatic plants in submerged baskets do best with soil specifically designed for them. Swamp and littoral plants should be placed at the water’s edge or just beyond it. Can be given aquatic plant fertilizer.
Place in specially designed baskets at the bottom of the pond. Lilies need annual fertilizing with a special fertilizer.

Ready, Set, Go!

Now that you’ve learned all about the different types of ponds as well as the tools and materials you’ll need to create a water garden in your backyard, check out our DIY project for step-by-step instructions on how to create and maintain your pond.
SEE THE STEP-BY-STEP GUIDE

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