How to build a wildlife pond

By Steve Harris- Updated on 19th June 2012

How to make a garden pond article spread

In both summer and winter, a well managed pond can heave with wildlife.

Ponds are one of the most important features to include in a wildlife-friendly garden because a huge variety of species depend on them. And they can be great places to sit and watch anything from bats to birds.

Roughly 1 in 10 British gardens has a pond – about two million in total – and these form an incredibly important network of wetland habitats throughout our urban areas. In addition to the wildlife that lives in and around ponds, they are also the focus of interest for passing mammals and birds.

Foxes, badgers, woodpigeons, blackbirds and starlings drink or bathe in them (a branch across your pond will encourage birds), and hedgehogs hunt slugs and invertebrates in the long vegetation around their edges, especially in hot, dry weather.

Where you dig your pond is critical: shadier sites will host different species to sunnier ones, while a shallow pond in a hot spot will be subject to excessive evaporation and algal blooms. In fact, small ponds are prone to drying out, so it’s best to position them in sheltered locations.

And while shallow ponds will be good for common species such as frogs and palmate newts, larger, deeper ones are more likely to be inhabited by toads and even great crested newts. If you have the space, more than one pond in various locations with different designs and plant species will add to the overall wildlife diversity in your garden.

WILDLIFE TO ATTRACT TO YOUR POND

In winter:

A few common (smooth) newts will overwinter in a pond, as will frogs and any tadpoles that did not emerge the previous summer.
Great pond snails are less active in the winter and are generally found in the deeper parts of a pond. In the summer, they are often seen at the surface, gulping in air.
Dragonfly nymphs spend three or four years in a pond before emerging as adults; they do not pupate. They feed on other invertebrates and larger nymphs hunt tadpoles.
Water hog-lice (Asellus spp) are extremely abundant in the detritus at the bottom of ponds, and eat rotting vegetation. They resemble, and are close relatives of, wood lice.

In summer:

Ponds attract flocks of birds, such as starlings, to bathe, foxes to drink, and sparrows and pipistrelle bats to feed on their abundant insects.
Damselflies/dragonflies will lay their eggs on aquatic plants or drop them onto the surface of a pond throughout the summer.
Common pondskaters are bugs that live on the surface of a pond, where they grab and eat the insects that fall into the water.
Common backswimmers fly at night and are one of the first species to colonise a pond. They are voracious predators of other aquatic life.
Daphnia waterfleas are eaten by adult and larval newts, as well as other aquatic insects. They filter algae from the water and thereby help to keep a pond clear.

THE BEST PLANTS FOR YOUR WILDLIFE POND:

Ponds with the greatest variety of plants have the greatest range of wildlife, so grow a diversity of species and control the more vigorous ones.

Pond plants are expensive to buy, but most pond owners pull out masses each year, so get them for free from friends.

Oxygenators are submerged plants that oxygenate the water and they are an important food source and habitat for aquatic life. Grow curled pondweed, mare’s tail, water milfoil and water-starwort. Yellow water lilies have both submerged leaves that provide oxygen and surface leaves that offer shade.

Marginals grow around pond edges and flower above water, providing perches and food for hoverflies and bees. Plant bur reed, flowering rush, great spearwort, water plantain, water speedwell and yellow flag (iris sawfly larvae eat the leaves).

Bog plants grow in wet ground. Plant bog bean, St John’s wort, creeping Jenny, fleabane (to attract insects), greater bird’s foot-trefoil (bees), hemp agrimony (butterflies), lady’s smock (the foodplant of orange tip butterfly larvae), marsh marigold, meadowsweet, purple loosestrife (hoverflies), rushes, sedges, watercress, and water forget-me-not.

Avoid invasive alien plants, such as Australian swamp stonecrop, Nuttall’s pondweed and parrot’s feather (all sold in garden centres). And steer clear of floating plants such as water fern. They choke the surface, reducing light and oxygen levels, and therefore diversity.

STEVE’S TOP TIPS:

It’s best to dig a pond in the autumn when the ground is soft, then let it fill up with rainwater and leave it to settle over winter. Clean it out in late autumn/early winter, but search through the removed vegetation to release trapped animals, or spread it around the pond’s edges so they can creep back into the water.
Preformed ponds are easier to install than those with butyl rubber liners, but a liner will enable you to design a more varied pond, with shallow sloping sides and a variety of depths. A maximum depth of at least 75cm will ensure that your pond does not completely freeze over during a hard winter.
Blanketweed and green algae tend to be a problem in new ponds and those with a large amount of water in direct sunlight. Remove blanketweed by hand and position plants at the pond margins to provide shade and so reduce water temperature.
Let the water level drop in the summer; damp mud is a good habitat for invertebrates. Even if the pond needs topping up, never do it with tap water.
If you have small children, either surround your pond with a fence or install a metal mesh or plastic grid just above the water surface that will support the weight of a child. Plants will grow through, and the mesh will also help to reduce the amount of debris that blows into the pond in the autumn.
Most insects and amphibians will colonise your pond naturally, but you will need to add water snails (both ramshorn and great pond snails), and species such as freshwater shrimp, waterlouse and freshwater (swan) mussels.

If you enjoyed this, read the previous part here.