A small pond, a big difference

Few things bring a British garden or woodland edge to life as quickly as a pond. Within weeks of filling one, you may find common frogs clumping spawn among the marginal plants, and by midsummer dragonflies will be patrolling the surface. Even a modest pool — say two metres by one and a half, and no deeper than sixty centimetres at its lowest point — can become the richest habitat on your patch. The secret is not size but shape: gentle, shallow edges and a good shelf of native plants.

Siting and shaping your pond

Choose a spot that gets sun for at least half the day. Dragonflies and most aquatic plants need warmth, and frogs will spawn in sunlit shallows. Avoid the drip line of a large deciduous tree — falling leaves will fill the pond and feed algae — but a little dappled shade is fine. Keep it away from heavy footfall and, if you have small children, fence or net the pond until they are older.

Dig a hole with a range of depths:

• A broad, shallow shelf 0–10 cm deep along at least one side. This is where frogs and toads will spawn, and where dragonfly nymphs can haul themselves out.
• A middle shelf around 20–30 cm deep for marginal plants and for amphibians to sit in.
• A small sump of 60–75 cm in the centre, where frogs and newts can overwinter below the frost line.

Line with butyl or a preformed liner, and leave a gentle beach of soil or stones at one end so hedgehogs and other wildlife can drink and climb out. Add a few logs and stones nearby for shelter.

Planting for frogs, dragonflies and birds

Native plants are the backbone of a wildlife pond. They provide cover, egg-laying sites and, crucially, places for dragonfly nymphs to climb when they emerge as adults. Plant in baskets of hessian or coir to stop vigorous species taking over. Good choices include:

• Marginals: marsh marigold (Caltha palustris), water forget-me-not (Myosotis scorpioides), water mint (Mentha aquatica), lesser spearwort (Ranunculus flammula) and flowering rush (Butomus umbellatus).
• Emergents for dragonflies: soft rush (Juncus effusus), water plantain (Alisma plantago-aquatica) and yellow flag iris (Iris pseudacorus) — the last is vigorous, so keep it in a basket.
• Oxygenators: hornwort (Ceratophyllum demersum) and water starwort (Callitriche species), which float free and shelter tadpoles.
• Floating: a single native white water-lily (Nymphaea alba) is too large for most small ponds; choose the least water-lily (Nuphar pumila) instead.

Avoid invasive non-natives such as New Zealand pygmyweed and parrot's feather — they are illegal to plant in the wild and will smother everything.

Filling and first months

Fill with rainwater from a butt if you can. Tap water contains chlorine and nutrients that encourage algae; if you must use it, let it stand for a few days first. Resist the urge to add fish — they eat tadpoles and dragonfly larvae. Do not introduce frogspawn either. Amphibians are surprisingly good at finding new ponds, and moving spawn risks spreading disease. If you build it, they will come.

Expect green water in the first spring. This is normal. As plants grow and shade the surface, the water will clear. Do not empty and scrub the pond; that destroys the tiny life that underpins the whole system.

Seasonal care through the year

A little gentle maintenance keeps the pond healthy.

• Spring: thin out blanketweed and duckweed by twirling it onto a stick. Leave it on the edge for a day so creatures can crawl back.
• Summer: top up with rainwater in dry spells. Leave the water level a little low if you can — it exposes muddy edges that birds use for bathing.
• Autumn: net out some fallen leaves, but leave a few. They provide cover for overwintering newts and insects.
• Winter: never smash ice — the shock can kill fish and amphibians. Instead, float a pan of hot water on the surface to melt a hole for gases to escape.

Wildlife to watch for

Common frogs often arrive within a season, their spawn appearing in jelly clumps in the shallows. Smooth newts may follow, and dragonflies — hawkers and darters — will hunt over the water by the first summer. Damselflies, with their delicate blue or green bodies, will lay eggs in submerged stems. Songbirds will bathe and drink at the edge, and hedgehogs may visit at dusk. A pond is never just a pond; it is a whole neighbourhood. Build it gently, plant it natively, and let the seasons do the rest.