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Why a Small Pond Is Worth the Digging

Water is the single most generous thing you can add to a garden. A pond takes up space that a border would otherwise have, yes, but it gives back in a way that a bed of shrubs never quite manages. Frogs arrive, usually within a year, often within a few months. Dragonflies patrol above it on warm afternoons. Blackbirds, thrushes and sparrows come down to bathe and drink, and if you plant it well, you will spend far more time sitting beside it than you ever intended.

The good news is that you do not need a large garden. A basin two metres by one and a half will do everything a bigger pond does, just with less of it. What matters far more than size is the shape of the thing: a sunken basin, some native plants, and at least one shallow edge that lets creatures climb in and out safely.

Choosing Where to Put It

Aim for somewhere that gets sun for part of the day and shade for the rest. Full sun in a small pond encourages algae and heats the water too quickly; deep shade suppresses almost everything and keeps the water cold and lifeless. A spot with morning sun and afternoon shade is close to ideal.

• Keep clear of trees. Leaf fall in autumn will fill a small pond quickly, and hungry roots can puncture a liner. Leave a couple of metres of clearance.
• Think about visibility. A pond you can see from the kitchen window will be watched daily for years. Half the pleasure of slow living is noticing the small changes — the first spawn, the first dragonfly.
• Pick somewhere low-ish. Water flows downhill, and a pond sitting at the lowest point of the garden is easier to fill with rainwater and less likely to need topping up.

Digging the Sunken Basin

The trick with a small pond is to sink it rather than raise it. A raised pool with a proud lip looks tidy but gives wildlife nothing — no gradual entry, no damp marginal edge, no place for a hedgehog to drink. Set the water level roughly flush with the surrounding soil and you gain an enormous amount of habitat for free.

Dig down to about 60–75cm at the deepest point. That depth keeps the pond from freezing solid in a hard winter and gives frogs somewhere to sit out the cold. Around the edges, cut a shelf about 20–25cm deep and 25cm wide; this is where your marginal plants will sit, and where most of the wildlife action happens.

Line the hole with a butyl liner or a rigid preformed shell. If you use butyl, lay down a layer of old carpet, sand or purpose-made underlay first — a single stone pressed through from below will undo an afternoon's work. Leave plenty of overlap around the rim, tuck it into a shallow trench, and weight it with turf or flat stones so it disappears.

The Shallow Edge That Makes All the Difference

If you take one thing from this article, take this. A pond with steep sides is a pond that drowns things. Frogs, hedgehogs, beetles and thirsty birds all need a way in and out.

Build one end of the pond as a gentle slope, or create a beach of pebbles and stones that breaks the surface and rises gradually onto dry ground. Add a piece of rough wood half in and half out of the water, and a few stacked stones along one side. These small ramps cost nothing and turn a pond into a place that welcomes life rather than trapping it.

Leave the rim slightly untidy, too. A patch of longer grass, a log pile and a few damp stones at the water's edge give amphibians somewhere to hide during the day and somewhere to overwinter.

Planting It Up with Native Species

Native plants are the ones your local insects and amphibians have evolved alongside, and they will settle in faster than anything exotic. Buy from a supplier who sells genuinely British stock, and avoid anything labelled as invasive.

• Marginals for the shelf: marsh marigold, water forget-me-not, water mint, ragged robin, lesser spearwort and flowering rush.
• Oxygenators for the water: hornwort or water starwort, which keep the water clear without needing planting in soil.
• One small lily: a pygmy or dwarf variety will cover a little surface and shade the water, but resist anything larger in a small pond.

Plant in aquatic baskets filled with a low-nutrient loam, topped with gravel to stop the soil floating away. Aim for roughly half the water surface to remain open, so dragonflies can still reach it.

Filling, Stocking and the Year-Round Routine

Fill the pond with rainwater from a water butt. Tap water is fine in an emergency but it carries nutrients and minerals that feed algae, so keep a butt topped up through summer and use that instead.

Do not add fish. Goldfish eat tadpoles, stir up the silt and turn clear water green. A wildlife pond with no fish will support far more life than one with even a couple of small ones.

After that, the maintenance is mostly about restraint. Pull out blanketweed by hand in spring rather than reaching for chemicals. Net out fallen leaves in autumn, but leave the silt at the bottom alone. Resist the urge to tidy the margins. Top up in dry spells, and in the first year, simply watch: the water will go green, then clear as the plants establish, and one morning in early spring you will find a jelly-like mass of frogspawn in the shallows. That is the moment the pond stops being a project and starts being part of the garden.