How to make a wildlife pond

Location, location, location

First, think about where to put your pond. Invertebrates such as beetles, hoverfly larvae, dragonflies and damselflies are the beating heart of a good wildlife pond. For them to thrive, the pond will need to be in a sunny spot. Avoid trees or overhanging branches – the leaves will start to clog up the pond, leading to unsightly algae problems in future years.

Depth is another important consideration. Because gases diffuse more readily in and out of shallower ponds, most wildlife ponds need not be more than 30cm at their deepest. Generally, the larger your pond, the more species it will attract. However, if space is limited, any pond larger than a metre in diameter will still provide a big net gain to local wildlife, including frogs. 

Digging

Your plan sorted, it’s time to dig. First, mark out your pond’s perimeter with rope or string and then take off the top layer of turf with a spade. Put the turf to one side – you’ll need this later. Remove sharp stones and other items as you find them and, once finished, add a layer of old carpet or cardboard to the bottom of your pit.

You’ll need a shallow lip around the perimeter of the pond. This will be a thin shelf upon which the edge of your liner will be hidden when the pond is finished. Remember to check your levels frequently – a sloping pond will leave the liner exposed to the sun, leading to it warping prematurely and, potentially, splitting.

Lining

Durable, cheap and easily cut-to-size, most flexible synthetic liners (as they are called) provide more than a decade’s worth of wear-and-tear. Talk to your garden centre about the liner best suited to your budget. Don’t worry about trimming your liner just yet. Lay your liner over the pit and begin to fill it with water. The weight of the water will pull your liner into place. Always, always try to fill ponds with rainwater, even if that means raiding local water butts. Tap-water contains nutrients, including phosphates, that can readily be taken up by algae, whose uncontrolled growth can limit the pond’s wildlife potential.

Once your new pond is full to the brim with water, it’s time to cut back your liner. Make sure you leave a 30-centimetre overhang of liner around the water’s edge. This excess liner should neatly slot into the lip that you’ve dug around the pond edge. Gently cover the excess liner with the turf cuttings that you put to one side earlier. (Washed gravel or slabs are another way of hiding the liner exposed at the pond’s edges).

Now filled, it’s at this stage that you may notice the pond’s earliest visitors. On several occasions, within minutes of finishing the installation of a pond in mid-summer, I have heard the familiar plop of one of Britain’s biggest invertebrates, the great diving beetle, slipping rather clumsily into the water. Other early visitors include (non-biting) midges, egg-laying hoverflies and smaller water beetles.

Planting

Broadly, pond plants come in three categories: deep-water plants, shallow-water plants and wetland-edge plants. You should consider each of these zones when planting. If acquiring cuttings, the best advice is to keep it local – moving pond plants (and frogspawn for that matter) over long distances can inadvertently introduce non-native pathogens and invasive species that can cause problems for animals.

If you use a garden centre to source your plants then seek out native species – wildlife charity Froglife offers an excellent plant list. The reason that native plant species are so important to wildlife ponds is simple: these are the specific species to which UK invertebrates have spent thousands of years adapting. They are the food plants for their larvae; the nectar for the adults. They are, essentially, home.

Accessorise

When it comes to wildlife, people often ask one question: “When will my frogs arrive?” The answer to this depends on your pond’s accessory features. Being mid-rung on most food chains, frogs need places where their invertebrate prey thrives, but they also need to hide from the attentions of larger predators, such as foxes, owls and cats. Areas of thick foliage, log piles or rockeries next to the pond offer both important habitat requirements for them.

Connectivity is important, too. Like hedgehogs, amphibians benefit from having green corridors between gardens. If your pond is well connected, and there are plenty of hiding places, you’re all set. In spring and summer, many new ponds might expect frogs within a matter of weeks. Newts (which, among other things, feed on tadpoles) can appear within a year of a new pond being dug. Dragonflies and damselflies, too. Then the fairy-flies, the water boatman, the caddisfly nymphs, the saucer bugs, the beetles, the bats. A good wildlife pond can easily support more than 100 animal species.