Why a sheltered corner suits a wildlife pond

Most British gardens have one awkward corner that never quite earns its keep — shaded by a fence panel, a little too narrow for a border, always slightly damp underfoot. That is precisely where a small wildlife pond belongs. Sheltered spots hold warmth for longer, so dragonflies and damselflies linger in the lee of a hedge, and the water surface stays calmer, which makes it easier for frogs to spot movement and for birds to bathe.

Before you dig, check for buried services and be careful where water drains from. Ground that floods or carries run-off from a heavily fed lawn or a driveway will feed the pond nutrients and blanket weed. Leave at least a metre from a boundary fence if a neighbour might be anxious, and think about safety if there are small children. A pond needs sun for roughly half the day to thrive, so pick a corner that catches the afternoon light but escapes the worst of the wind.

Size, shape and lining

Even a modest pond of 1.5m by 1m will support a surprising amount of life. Aim for a maximum depth of 60–75cm at the centre: deep enough to avoid freezing solid in a hard winter, shallow enough for warmth to reach the bottom in spring. A wildlife pond needs no pump, no filter and no fish — in fact, fish are the single fastest way to empty a healthy pond of frogs, newts and dragonfly larvae.

• Choose a butyl rubber liner of around 1mm, laid over a geotextile underlay. Old carpet or a layer of sand also works as a cushion.
• To work out the liner size, add twice the depth to the length and width, then add 60cm to each figure for an overlap.
• A pre-formed rigid liner is quicker, but choose one with contoured shelves rather than steep, uniform sides.
• Undulate the outline. An irregular, wavy edge looks natural and creates pockets of still water and varied planting depth.

Shallow shelves and gentle edges

The margins matter more than the middle. Frogs, hedgehogs and thirsty birds all need a way in and out, so build in a sloping beach at one end — a gently angled ramp of liner covered in pebbles, extending from dry ground into the water. Without it, small creatures can become trapped.

• Create two shelves: one at roughly 20–25cm depth for marginal plants, another at 35–40cm for deeper-rooted species.
• Leave a log or a flat stone at the water's edge as a landing platform for bathing birds and emerging dragonflies.
• Keep some of the bank bare rather than sealing it under paving — bare soil encourages solitary bees and gives amphibians cover.
• Edge the pond with turf or loose stones rather than a tight line of slabs, allowing the liner to be hidden.

Planting in layers with British natives

Plant in bands that mirror the shelves, and keep roughly a third of the surface open water so light and oxygen can reach it.

• Marginals: marsh marigold, water forget-me-not, water mint, ragged robin, lesser spearwort, soft rush.
• Oxygenators: hornwort, water starwort and spiked water milfoil, which breathe life into the water and shelter larvae.
• Floating: frogbit in smaller ponds, or a single small water lily if you have room.
• Bankside: lady's smock, bugle and wild strawberry to link the water to the surrounding garden.

Buy from a reputable native aquatic nursery and never take plants or spawn from another pond, however tempting — you risk introducing disease and invasive weeds. Avoid New Zealand pigmyweed, water fern, parrot's feather and floating pennywort entirely; they are illegal to release into the wild and will strangle a small pond within a season. Use hessian-lined baskets with low-nutrient aquatic compost, or plant directly into a shallow layer of soil over the liner for a looser, more natural look.

Filling and the first year

Rainwater collected in a butt is ideal. Tap water carries chlorine and nutrients, and a single fill of a small pond can trigger a bloom of blanket weed. If mains water is unavoidable, let it stand for a day or two and expect green water for a while. Trickle it in over a sack or a sheet of plastic so the soil and shelves are not scoured out.

Then leave it alone. Green water in the first spring is normal and usually clears by early summer as plants grow, daphnia multiply and tadpoles graze. Resist adding barley straw or chemicals unless the plants genuinely fail — patience is the better remedy, and a pond left to find its own balance becomes far richer for it.

A year of gentle care

From late autumn, net or rake out fallen leaves before they rot and feed the algae; a few left in the depths will suit hibernating frogs and newts. Cut back only some of the stems, leaving the rest standing over winter for larvae and seed heads. In a hard frost, melt a hole in the ice by resting a pan of hot water on the surface rather than breaking it, which sends damaging shock waves through the water.

Watch for spawn in early spring — common frog spawn appears in clumps, toad spawn in strings — and let the tadpoles be. By midsummer, damselflies will be emerging on tall stems, and birds will be visiting daily. Do remember that great crested newts and their habitat are legally protected, so take advice before beginning work if they are present. Done well, a corner pond quietly becomes the busiest part of the garden.