How to Create a Wildlife-Friendly Garden Pond

A Pond Is the Best Thing You Can Do for Wildlife

If you only ever make one change in your garden for wildlife, make it a pond. Nothing else comes close. Within weeks of filling, insects will find it. By the following spring, you will almost certainly have frogs, and quite possibly newts and dragonflies as well. Even a pond the size of a dining table can support a surprising amount of life, so do not be put off if your garden is small.

The secret is not fancy equipment or expensive liners. It is shape. A pond with gently sloping sides, shallow edges and a few native plants will outperform a neat, straight-sided pool every time, because wildlife needs to be able to get in and out easily — and so do the creatures that fall in by accident.

Choosing the Spot and Planning the Shape

Pick a position in partial sun: a few hours of direct light encourages plants and warms the water, but full sun all day leads to green soup in summer. Keep it away from large trees, which drop leaves and suck moisture from the soil. If you have young children, remember that an open, ground-level pond is far safer than one with steep, slippery sides, but always supervise — and consider a rigid metal grid just below the surface while children are small.

In terms of size, aim for at least 1.5 metres across and 60 to 75 centimetres deep at the centre. That depth means frogs and newts can overwinter in the mud without the pond freezing solid, and it gives dragonfly larvae the stability they need. If space is tight, a half barrel with a small planting shelf will still bring in insects and birds.

• A shallow beach: one edge should slope very gradually, like a natural shoreline, giving hedgehogs, birds and amphibians a safe route in and out.
• A planting shelf: a flat ledge about 20 to 30 centimetres deep around part of the perimeter for marginal plants.
• A deep centre: roughly half the surface area, for overwintering wildlife and a refuge in hot spells.
• An irregular outline: wavy edges with a couple of bays create varied micro-habitats and look far more natural.

Digging, Lining and Filling

Mark out the shape with a rope or hosepipe, then dig in layers, working from the outer edge inwards so you can stand outside the pond as you go. Keep the spoil nearby — it makes a lovely bank for planting. Remove sharp stones and roots, then line the hole with a layer of soft sand followed by a geotextile fleece, before laying butyl or EPDM liner. Leave plenty of overlap around the edges and tuck it into a shallow trench, hidden under turf or gravel.

Fill with rainwater collected in a water butt wherever possible. Tap water is fine if you have no alternative, but it contains nutrients that feed algae, so let it stand for a few days before planting and expect a green flush in the first season. Build the pond in spring or autumn, when the soil is workable and wildlife is on the move.

Planting With Native Species

Native plants support far more invertebrates than exotic varieties, and they will colonise naturally if you leave a few nearby. Aim for roughly half the water surface to be open, so dragonflies can hunt and birds can bathe.

• Marginals for the shallow shelf: marsh marigold, water forget-me-not, brooklime, water mint and ragged robin.
• Oxygenators for the deeper water: hornwort and water starwort, which keep the water clear and shelter tadpoles.
• Floating and deep-water plants: a small native water lily or frogbit to provide shade and cover.
• Structure for emerging dragonflies: leave some tall, straight stems standing through the summer.

Do avoid invasive thugs such as New Zealand pygmyweed, floating pennywort and parrot's feather. Once they are in, they are almost impossible to remove. Likewise, leave out fish — even a few goldfish will clear a pond of tadpoles and insect larvae within a season.

Encouraging Frogs, Newts and Dragonflies

Never introduce frogspawn or plants from another pond. You risk bringing in disease and invasive species, and your pond will be found by amphibians on its own — often within a single breeding season. Frogs usually arrive first, spawning between February and March, with newts following in spring. Dragonflies and damselflies turn up in midsummer and will lay eggs among the submerged stems if the planting is right.

Help them along by leaving a wild, undisturbed corner nearby: a log pile, a patch of long grass and a few stones give amphibians somewhere damp to shelter when they leave the water. Add a small ramp of stones or a piece of wood at the shallow edge so anything that falls in can climb out.

Looking After the Pond Through the Year

A wildlife pond needs very little maintenance, and too much tidying does real harm. In autumn, scoop out fallen leaves before they sink, but leave some in the water — they are food for larvae. In winter, if the surface freezes, float a small ball or place a pan of hot water on the ice to keep a hole open for birds and amphibians. Never smash the ice, as the shock can kill wildlife beneath.

In spring, thin crowded oxygenators and twirl blanketweed out with a stick, leaving it on the pond edge for a day so any creatures can crawl back in. Top up with rainwater in dry spells. That is genuinely all it takes — and in return you will get frog chorus, darting newts and the flash of dragonfly wings for years to come.