Water in any form in the garden attracts a certain amount of wildlife and adding a pond is as easy as digging a hole and filling it with water.
Designing a landscape feature that provides a haven for wildlife requires a little more planning and effort. The bigger the pond the easier it is to maintain the ecological balance.
Give it an irregular, curved outline to look more natural and vary the depth for a wide selection of plants.
Include a beach that slopes gently down to an area of shallow water and an underwater shelf around the edge for marginal plants. These features will help wildlife climb out of the pond.
Check with your local council before starting work as there are laws regarding putting up a fence depending on the depth of the water.
Find the site
There are several factors to take into account when choosing a location in the backyard for a wildlife pond.
Avoid shady spots, choosing a site that receives sun for most of the day.
Locate the pond in the open, away from overhanging trees or big shrubs.
Large roots can tear the liner and fallen foliage pollutes the water, plus the leaves of certain evergreens such as yew and laurel are toxic.
Pick a spot that is sheltered from cold winds so the water temperature is less likely to fluctuate, making the pond a healthier habitat for both aquatic plants and wildlife.
Measure the area as the pond should be a minimum of 2 x 2.5m in size.
Check for pipes and other underground services before excavating by contacting water, electricity and gas utility companies.
Adding aquatic plants
To prevent it turning green, a pond needs the right balance of plants to keep the water naturally clear.
Plants contribute to pond health, helping to stabilise water temperature and reduce erosion. Oxygenating plants take up nutrients that encourage algae.
Plants provide shelter, breeding sites and feeding grounds for aquatic animals. A wildlife pond attracts birds, amphibians and insects to drink, bathe and breed.
Never keep fish in a wildlife pond as they will feed on both the tadpoles and insects.
To grow pond plants, use plastic baskets and a specially formulated aquatic potting mix, positioning them in deep water and on the underwater shelf.
IN DEEP WATER grow waterlilies or lotus. These varieties need a depth of 450 to 600mm.
ON THE SHELF add shallow-water varieties that need a depth of 200 to 400mm such as water snowflakes, poppies and native oioi.
FOR THE EDGE landscape with bog varieties like water ranunculus, sweet flag and sweet rush.
ADD FLOATING PLANTS like crystalwort and fairy moss to shade a third of the water’s surface, to stop the build-up of algae and blanket weed.
Choose the liner
A flexible liner is a better option than rigid preformed shells for creating a wildlife pond. Flexible liners can be used to create a pond of any size, shape or depth and are easy to install.
Choose a liner that will last, as cheaper materials have a shorter lifespan and poor resistance to UV.
Liners come in various sizes, so take this into account when planning the dimensions of the pond.
To protect the liner from sharp objects that could tear it, position an underlay in the base of the pond. Old carpeting can be used or pour a 50mm deep layer of sand.
Vary the edging of the pond to create a natural effect and give the maximum benefit to wildlife.
USE SMALL PEBBLES and gravel for a beach, hiding larger stones in the water to maintain the edge.
SET PAVING SLABS in the ground near the water’s edge to provide viewing platforms, creating up to three for a very large pond.
POSITION LOGS and large bush rocks around the perimeter of the pond and at the water’s edge to provide hiding places for frogs and other wildlife.
Use a garden hose to lay out the shape of the pond on the ground and view it from several angles, including up high from a second storey window if possible. Trickle sand onto the ground to mark the outline on the grass then remove the hose.
Dig inside the sand outline with a spade, sloping the sides outwards by 20°. Shape a 300mm deep and wide underwater shelf around the inner edge of the pond. Outside the sand outline, remove a 450mm strip of turf to 50mm deep for liner overlap.
Position a spirit level on a board and use it to check the rim of the pond is level all around. Remove any debris and protruding stones from the hole that could damage the liner. Firm the sides by hand to avoid any soft spots that could subside later.
Position a protective underlay, such as carpet or sand, in the base of the hole. Cut the flexible pond liner to size then lay it loosely over the hole, checking it is centred. Weigh down the edges temporarily with bricks, taking care not to damage the liner.
Use the hose to fill the pond and the increasing weight will mould the liner to the shape of the hole. As it sinks, remove the weights and fold the liner neatly around corners and the underwater shelf. Continue filling until the water is just below the rim.
Trim the liner with an overlap of 150mm all around. Bury the outside edge of liner in the soil, leaving a rim 80mm wide. At the beach, extend the liner 150mm out of the water. Cover the rim with edging materials and the beach with pebbles, then add plants.