Työkalut kotiin & puutarhaan

Installing a garden pond: Creating the perfect water feature for your garden

A natural pond in a garden setting, surrounded by evergreen plants.
Installing a garden pond isn’t difficult, however there are a few important points to keep in mind

There are many wonderful advantages to installing a pond in your garden. Not only does it make for a wonderful, home water feature – it also provides a valuable habitat for a range of plants and animals. From fish and frogs to dragonflies and toads – enhance your own miniature ecosystem and bring new life into your garden. The same goes for a host of colourful aquatic flowers, such as water lilies, pickerel rushes, marsh marigolds and many more. Check out our pond guide for design tips and information on the right materials to use.

In this article we will advise you on what you need to know when installing your natural pond and demonstrate how to complete the installation in five steps. A brief word of caution: As lovely as a pond can be, it may also prove dangerous to people and animals. After all, even the smallest body of water – provided that it’s deep enough – can be hazardous for anyone unable to swim.

How to choose the perfect location

Verdant lawn in a garden.

When selecting a location for your pond, make sure to rule out any spots directly under the canopies of trees. Roots interfere with the excavation process, and falling leaves can compromise water quality. You would also do best to avoid any spots where the sunshine is too intense. A pond that is too warm will have higher water temperatures which could encourage runaway algal growth. The ideal location will allow portions of the water’s surface to be shaded throughout the day. However, even if your selected location fails to provide shade, there is an alternative solution to explore: You could create your own shade by planting bamboo or other plants on the banks of the pond. 

It is also important to maintain certain minimum distances between the pond and your property, your neighbours’ property or any streets. However, no standard rules apply here. Tolerances vary based on country and can even differ by state or region. In addition, building permits are required for ponds of a certain volume – and these must be granted before you even take shovel to soil.

The right time to install a garden pond

Tulips blooming in a garden.

Spring is the best time of year to install your pond. If your pond is installed between March and May, it will have time to establish its own biological equilibrium. However if you plan to install your pond in the fall, we recommend delaying any planting until the following spring.

Not all water is the same

White waterlily blossoms float on the surface of a pond while goldfish swim below.

Generally speaking, it is perfectly fine to fill your pond with water from the tap. However, it is advisable to contact your utilities provider to inquire about the water quality first. This is particularly important if you plan to make your pond a home to exotic plants or animals. Make sure to take note of the temperature, water hardness and carbonate hardness, pH level and carbon dioxide concentration. These properties affect all other water quality parameters, meaning that if they get out of balance, other variables shift automatically, which may adversely impact the water quality of your pond.

The water temperature in your pond should remain between 25 and 35 degrees Celsius in summer and between 4 and 14 degrees Celsius in winter. The carbonate hardness (or the amount of dissolved minerals, including calcium and magnesium) should not drop lower than 5 dKH (degrees of carbonate hardness). The ideal value lies between 6 and 10 dKH, and a value of 14 dKH is far too high. This metric is part of the overall water hardness value. Water hardness is measured in dGH (degrees of general hardness) and should stay within a range of 8 to 10 dGH. You can measure carbonate hardness using a set of test strips. The same applies to the general water hardness. pH, which describes the concentration of hydrogen ions in the pond, should ideally be between 7 and 8. The most reliable methods of measuring pH are pH drop tests and digital water testers. We recommend testing your water pH every two to three weeks. The carbon dioxide concentration should not exceed 30 mg/l. Helpful hint: When you fill your pond with water for the first time, you may notice that the water becomes cloudy after a few days. But don’t fret. In most cases, the discolouration disappears all on its own. Your biological ecosystem simply requires a few days to find its groove.

Technical equipment: Yes or no?

A garden pond surrounded by evergreen plants; water bubbles from a fountain in the pond.

Filters, pumps, filter materials and water fountains – there is an enormous range of extras available for your garden pond. And of course there is an application for each one. But keep in mind that a properly planned pond without fish or with only a small fish population doesn’t require any equipment at all. If you plan to host a larger fish population or higher-maintenance species such as koi, you will need to install a pond filter system. This type of system uses different chambers to purify the water. Larger dirt particles are collected in the first chamber while toxic substances are concentrated in the last chamber. The size and capacity of the filter system you need will depend on the size of your pond as well as on your local weather conditions and choice of aquatic fauna. You will require a water pump if you want the water to move against its natural gradient, for example in the case of a built-in stream. And of course, lighting can enhance the ambience of the scene, although it is not required in any way for pond maintenance.

A pond built to appeal to plants and animals

Illustration showing the three basic zones of a natural pond – marginal zone, deep marginal zone and deep water zone – with additional information provided in the graphic.

The ideal pond consists of three basic zones: the marginal zone, the deep marginal zone and the deep water zone. The marginal zone reaches a depth of 10 to 20 cm and forms a transitional area between the water and the shore. Marginal plants are particularly well-adapted to this zone. Make sure that the edges and embankments of your pond are not too steep; birds and frogs love wading among the marginal plants. When planning your pond, make sure that this zone spans over about one third of the pond’s total surface area. The deep marginal zone plays an important role in pond ecology and lies at a depth of about 20 to 50 cm. This zone contains a multitude of aquatic plants which help to control the growth of algae. The deep water zone begins at a depth of around 60 cm. This is the favored depth for waterlilies and other deep submerged plants. If you plan to add fish to your pond, this zone should be at least one metre deep. This provides fish with a comfortable environment even through winter frosts and hot summers.

Disposing of excavated material

A shovel is driven into the ground by a person wearing rubber boots.

Installing a garden pond often involves excavating large quantities of soil, most likely more than you will be able to use in your garden itself. The rest must be disposed of properly. One option would be to bring it to a local waste disposal facility, however these facilities will often charge a fee. Another option would be to place an ad online. Smaller quantities of soil are often prized by gardeners as a natural material. Some countries even have soil markets where gardeners can sell their own topsoil.

Safety notice: Ponds present a danger to people and animals

A small child kneels on the bank of pond.

A pond in your garden can be a source of joy. But you must never forget about the dangers associated with a body of water. An incorrectly dug bank or marginal zone often presents the most serious threat. If this area is too steep or slippery, people and animals may be apt to lose their footing. Children are naturally fascinated by water. So make sure that children are never allowed to play unsupervised near a pond, and erect the necessary barriers, such as fencing, to ensure that strangers are not accidentally injured. You may also choose to install additional safety measures, such as nets, grating or electrical alarm systems.

Quick and easy installation: 5 steps to your own garden pond

A person kneeling on the ground and spreading out a black pond liner.

Step 1: Select a location and mark out the area

Before putting shovel to soil, carefully select the location for your pond and mark the perimeter using a few branches and a length of string. Then stake out the marginal and deep marginal zones and prepare a sketch showing the depth of each individual zone as well as the slope of the transitional areas. The inner walls should not have a slope greater than 30 degrees.

Step 2: Excavation

Carefully remove the turf (both grass and roots) from the deeper level of soil. You may be able to use it later on in the installation process. And now the hard work begins: Start excavating the different layers of soil in your garden. Proceed precisely according to your drawing and make sure that your pond area is free from any pipes or tubing. If you are able to do so, obtain the landscaping schematics for your property prior to digging. After the soil has been excavated, remove any sharp stones or roots from the pond bed. You may also add a layer of sand or a textile underlayment to better protect the liner.

Step 3: Calculate the size of the pond liner

You can either calculate the exact area or use a simple rule of thumb: Liner length = pond length + 2 x pond depth (as measured at the deepest point) + 60 cm overlay. Liner width = pond width + 2 x pond depth (as measured at the deepest point) + 60 cm overlay.

Step 4: Install the pond liner

Now line the hole you have excavated with the pond liner. Make sure the weather is not too cold. At temperatures over 15 degrees Celsius, the liner will be easier to install and adjust as needed. When cutting your liner to size, make sure to leave a generous overlay along the entire perimeter. Then fix the liner in place by placing stones and earth along the overlay section.

Step 5: Fill the pond with water and add plants

Start by filling your pond to about one third of its total volume. This way, the weight of the water will smooth out the liner. The water should now be at the level of your deep water zone. Add the plants you have selected for the deep water zone. Then proceed to gradually fill the rest of the pond, adding additional plants as you go. Your garden pond is finally ready!

Helpful hint:
Do you happen to have a rainwater collector near the location you have selected for your pond? Then we recommend using the new Bosch GardenPump 18 to pump in the water. There’s no easier way to fill up your little garden ecosystem. And thanks to the 18 V battery from the 18 V Power for ALL battery system, you won’t even need to find an electrical outlet.