Why a tiny pond earns its keep

A pond the size of a washing-up bowl can hold more life than the rest of a small garden put together. Frogs, newts, damselflies, hoverflies, bees stopping for a drink and blackbirds hopping in for a bath all use these little puddles. In a courtyard or a narrow town garden, water is the single most valuable thing you can add, and it doesn't need to be big, formal or expensive. You just need to get three things right: depth, access and planting.

Forget fountains and pumps. Still water with plenty of plants is what wildlife wants, and it's far easier to look after.

Choosing a container and where to put it

Almost anything watertight will do: a half barrel, an old butler sink, a rigid liner, a deep trug, or a large glazed pot with the drainage holes sealed. Aim for something holding at least 60–100 litres, with a depth of 30–45cm in the middle. That depth keeps the water cool in a heatwave and gives frogs somewhere to sit out the winter.

Site it where it gets part sun and part shade — a few hours of morning sun is ideal. Avoid the foot of a north-facing wall that never warms up, and keep clear of overhanging trees, which will fill it with leaves. If you're burying a bowl, dig the hole so the rim sits 2–3cm above soil level, then backfill around the sides and firm it in. That stops soil and slug pellets washing in, and keeps the rim tidy enough to look deliberate.

• Level the container carefully before filling — an uneven rim looks scruffy and makes planting awkward.
• Fill with rainwater from a butt wherever you can. Tap water is fine in an emergency, but let it stand for 48 hours first so the chlorine disperses.
• Add a bucketful of water from a friend's established pond if you can. It kick-starts the microscopic life that everything else feeds on.

Building in a gentle slope for access

This is the step most people skip, and it's the one that decides whether your pond is a home or a trap. Hedgehogs, frogs, beetles and fledgling birds all need a way out that isn't a vertical wall.

At one end, build a shallow beach by stacking flat stones so they step down into the water, with the top stones sitting just above the surface. Alternatively, lay a piece of roughened wood or a mossy log at an angle of no more than 40 degrees, running from dry ground into the water. A strip of old towel or a piece of gravel-topped plank works too. The surface needs to be rough — frogs can climb wet stone, but they can't climb plastic.

Around the rim, leave a few stones with gaps between them. Damp crevices suit insects, and the stones give birds a place to perch and preen after bathing.

Planting that does the heavy lifting

In a small pond, three or four plants is plenty. Aim to cover roughly a third of the water surface, leaving open water for birds and for dragonflies to hover over.

• Oxygenators: hornwort or water starwort, both submerged and undemanding. These keep the water clear and give tadpoles cover.
• Marginals: brooklime, water mint, water forget-me-not, marsh marigold or lesser spearwort. All are native, all cope with a small pot, and none will swamp the pond.
• Edging: creeping jenny or ragged robin around the rim, softening the plastic or glazed edge.

Plant in aquatic baskets using proper aquatic compost, then top the compost with a layer of gravel so it doesn't cloud the water. Stand the baskets on bricks or upturned pots so the crowns sit at the right depth — usually just below the surface for marginals, deeper for oxygenators. Avoid yellow flag iris, bulrushes and anything described as vigorous; they'll fill a barrel within a season. Skip duckweed and floating pennywort entirely.

And no fish. In a pond this small, goldfish will eat every tadpole, cloud the water and need feeding and filtering. Wildlife will arrive on its own.

Finishing touches and planting for shelter

Leave one side of the pond a little unruly. A clump of long grass, a small log pile or a bundle of hollow stems nearby gives frogs and newts somewhere to shelter on land, which they need for most of the year. Dense cover within a metre or two of the water makes the whole thing far more attractive to amphibians.

Don't use slug pellets, weedkiller or insecticide anywhere near the pond, and wash your hands after handling pond plants rather than rinsing them over the water.

Looking after it through the year

• Summer: top up with rainwater in dry spells, ideally little and often rather than one big splash.
• Autumn: stretch a net over the surface for a few weeks to catch falling leaves. Leaves left to rot turn the water green and soupy.
• Winter: never smash ice — the shock can kill frogs resting below. Float a small ball to keep a hole open, or stand a pan of hot water on the surface.
• Spring: resist the urge to tidy. That's when spawn, tadpoles and newt eggs are in the water. Thin overcrowded plants in late summer instead, once the young have left.

Beyond that, leave it alone. A pond that looks slightly mossy and a bit overgrown is a pond that's working.