Why a small pond earns its place

A pond is the single most effective thing you can add to a small garden for wildlife. Even a modest 1.5 by 2 metres will pull in frogs, newts, damselflies, dragonflies, pond skaters and water boatmen, and it will become the local bathing and drinking spot for blackbirds, sparrows and the occasional hedgehog. As natural ponds have disappeared from the British countryside, garden ponds have quietly become a genuine refuge. You do not need a large plot, a pump or a filter — you need water, sloping edges and a handful of native plants.

Choosing the spot

Pick a position that gets sun for at least half the day. Warmth encourages dragonfly larvae to develop and helps plants flower, while some afternoon shade keeps the water from turning into green soup in July. Keep it away from large trees, whose roots can puncture a liner and whose leaves will fill the pond every autumn. Level ground is easier than a slope, though a slope can be worked with by building up one edge with the spoil you dig out.

If you have small children, a pond is still possible. A shallow beach or a rigid grille set just below the surface gives a safe margin, and a raised pond with a sturdy edge is another option. Supervise young children and teach them early that the pond is a place to look, not to paddle.

One rule worth holding to: no fish. Goldfish and even the smallest natives will make short work of tadpoles, newt larvae and insect life. A wildlife pond is a pond without fish.

Digging and shaping

Mark out the shape with a hose or a length of string — a wavy, irregular outline looks more natural than a circle. Dig in layers:

• A central area around 60–75cm deep, which gives frogs somewhere to overwinter and stops the pond freezing solid.
• Planting shelves at roughly 20cm and 40cm deep around part of the edge, wide enough for baskets or a few pots.
• A shallow beach at one end, sloping gently from the water's edge down to about 10cm. This is the single most important feature for wildlife: frogs, birds, hedgehogs and beetles all need a way in and out. Without it, creatures fall in and drown.

Line the hole with a layer of soft sand and old carpet or underlay, then a butyl liner (or a preformed rigid liner for very small spaces). Leave plenty of overlap, tuck the edges under turf or cover them with pebbles and logs, and hide the liner with stones and planted margins. Fill with rainwater from a water butt if you can — tap water contains nutrients that feed algae.

Planting it up

Choose British native plants, which support far more native insects than ornamental varieties. Good choices for a compact pond include:

• Marginals for the shelves: marsh marigold, water forget-me-not, brooklime, water mint, lesser spearwort.
• Oxygenators: hornwort and water starwort, which stay submerged and keep the water clear.
• Floating: a small water lily or frogbit — but keep it to a third of the surface at most.

Plant into baskets using heavy loam, not potting compost, and top the compost with gravel to stop it clouding the water. Avoid invasive non-natives such as floating pennywort, parrot's feather and water fern — they spread alarmingly fast and will swamp a small pond in a season. Around the edge, leave a patch of longer grass, a log pile or a small stone stack so frogs, newts and insects have somewhere to shelter when they leave the water.

Keeping it healthy

Maintenance is light. Top up with rainwater in summer, and thin blanketweed by twirling it around a cane rather than reaching for chemicals. In autumn, scoop out fallen leaves before they sink and rot, but do not tidy everything — leave the dead stems of marginals standing through winter, as insects and frogs use them as cover. Never empty and scrub the pond clean; a small amount of algae and debris is part of a working ecosystem. A small solar fountain can add a little movement and aeration without disturbing the inhabitants.

What you will see

Give it a season. Frogs usually arrive first, often within weeks, followed by newts and the first damselflies by midsummer. Dragonflies patrol from June, and birds will use the beach to bathe and drink. Never move frogspawn between ponds, as this can spread disease. A pond takes a year or two to settle into itself, and it will look better for it. Within a couple of square metres, you will have created one of the richest habitats a British garden can hold — and you will find yourself checking it every morning.