Why a wildlife pond is the best thing you can build

There is nothing quite like the sight of frogspawn in early spring, or the flash of a dragonfly over water on a warm July afternoon. A garden pond, even a small one, can become a haven for British wildlife. It doesn't need to be large or expensive. A sunken washing-up bowl will do for a start, though a pond of two or three square metres will support far more life. The key is to think like a frog or a dragonfly: they need shallow water, gentle edges, and plenty of native plants. Get these basics right, and your pond will soon be alive with croaking, buzzing, and darting iridescent colours.

Choosing the right spot and size

Pick a spot that gets plenty of sunshine for at least half the day. Dragonflies and damselflies need warmth to hunt and mate, and most aquatic plants flower best in sun. Some shade is fine, but avoid a pond directly under trees: falling leaves will rot and strip oxygen from the water. A size of 2–3 metres across and up to 60 cm deep in the middle is ideal. This depth keeps the water cool in summer and stops it freezing solid in winter, giving frogs somewhere to overwinter. If you have space, a larger pond is even better, but small is beautiful too. Just make sure it is away from heavy foot traffic and curious pets.

Designing gentle slopes and shallow margins

The most important design feature is a gentle slope. Frogs, toads, and newts need easy access in and out of the water. A steep-sided pond can trap them. Create a beach-like edge on at least one side, sloping gradually from dry land to a depth of 10–15 cm. Line the slope with smooth pebbles or gravel to prevent soil washing in. Dragonfly larvae climb out of the water on emergent plant stems, so leave some stems standing. Avoid using a rigid preformed pond with vertical sides unless you add a ramp. A butyl or EPDM liner gives you freedom to sculpt the shape you want. Remember: no fish.

Planting native species for shelter and spawning

Native plants are the backbone of a wildlife pond. They oxygenate the water, provide cover for tadpoles, and give dragonfly nymphs a ladder to climb. Aim for a mix of submerged, floating, and emergent plants. Good choices include:

• Submerged: hornwort, water crowfoot, and spiked water-milfoil.
• Floating: broad-leaved pondweed and water lilies (native species only, such as Nymphaea alba).
• Emergent: marsh marigold, water forget-me-not, yellow flag iris, and flowering rush.
• Marginal: ragged robin, purple loosestrife, and lesser spearwort.

Plant in baskets of hessian or mesh to stop roots taking over, or use a layer of subsoil and gravel. Avoid invasive non-native species like New Zealand pygmyweed. Leave some leaf litter at the bottom — it's food for larvae and shelter for overwintering insects.

Why fish and frogs don't mix

If you want frogspawn and dragonfly larvae to thrive, do not put fish in your pond. Even small goldfish will eat frogspawn, tadpoles, and dragonfly nymphs. They also stir up sediment and eat the tiny invertebrates that dragonflies depend on. A fish-free pond quickly becomes a nursery for amphibians. Frogs will find your pond within weeks if there are other ponds nearby. Newts may also arrive, and they are a joy to watch. If you already have fish, consider creating a separate small pond for wildlife, or rehoming the fish. It's a simple choice: fish or frogs, not both.

Looking after your pond through the seasons

Maintenance is minimal if you get the balance right. In spring, watch for frogspawn and avoid disturbing it. In summer, keep the water topped up with rainwater from a butt — tap water contains chlorine and nutrients that encourage algae. Remove excess blanketweed by twirling it around a stick, but leave some for tadpoles to graze on. In autumn, net out fallen leaves before they sink, but leave a few for overwintering insects. Never empty and scrub your pond; that destroys the delicate ecosystem. In winter, float a ball on the surface to prevent ice sealing the pond and trapping toxic gases. Then wait. Nature will do the rest, and you will be rewarded with a garden that hums, croaks, and shimmers with life.