A Pond for Every Garden

You do not need acres of land to make a real difference for British wildlife. A pond the size of a dining table, sunk into a sunny corner, can become the busiest habitat in your garden. Frogs will find it within weeks, dragonflies will patrol it by midsummer, and hedgehogs will visit for a drink on warm evenings. The secret is not size but shallowness: a gentle slope, a few native plants and clean rainwater are far more valuable than a deep, sterile pool. Even a half-barrel or an old washing-up bowl buried to its rim will attract life, though a properly lined pond gives you more scope for planting and supports a wider range of creatures.

Choosing the Right Spot

Position matters more than you might think. Aim for five or six hours of sun a day, because warmth encourages algae-eating invertebrates and helps dragonfly larvae develop. Some afternoon shade is useful, as it keeps the water from overheating and reduces blanket weed. Avoid placing your pond directly beneath deciduous trees: falling leaves rot and strip oxygen from the water, and roots can puncture a liner. Keep it away from the house if you have very young children, and check for underground cables before you dig. A level site is easiest, but a gentle slope can become a small pebble beach on the downhill side.

• Full sun for at least half the day, with dappled afternoon shade.
• At least 2 metres from a mature tree or hedge.
• Visible from a window or patio so you can enjoy the comings and goings.
• Within reach of a water butt or downpipe for easy top-ups.

Size, Shape and Lining

A pond of 1.5 metres by 2 metres is ample for a small garden, though even 1 metre square works well. Dig to a maximum depth of 45 to 60 centimetres in the centre, with a shelf around the edge at 20 to 25 centimetres deep. That shelf is where you will stand your marginal plants, and it also gives amphibians a safe route in and out. Line the hole with a butyl or EPDM liner over a layer of old carpet or sand to protect against stones. Once the liner is in, tuck it under turf or paving, and build a shallow ramp of stones or a piece of rough wood from the water to dry land. Hedgehogs, frogs and even the occasional toad will use it to climb out; without one, small animals can become trapped. Fill the pond with rainwater from a water butt, never tap water, which contains chlorine and nutrients that feed algae.

Planting a Native Paradise

Plants are the engine room of a wildlife pond. They oxygenate the water, provide cover for larvae and tadpoles, and offer landing pads for emerging dragonflies. Use a mixture of oxygenators, marginals and a few floating-leaved plants, but avoid invasive non-natives such as floating pennywort or water hyacinth, which can smother a small pond in a single season. Good native choices include:

• Oxygenators: hornwort, water milfoil and curled pondweed, which grow happily in deeper water.
• Marginals: marsh marigold, water forget-me-not, ragged robin, lesser spearwort and yellow flag iris.
• Floating-leaved: white water lily (choose a dwarf variety for small ponds) or broad-leaved pondweed.
• Edging: lady's smock, meadowsweet and native sedges to soften the rim and shelter emerging insects.

Plant in aquatic baskets filled with loam-based compost, topped with gravel to stop the soil clouding the water. Aim to cover no more than half the surface with floating leaves. Resist the temptation to add fish: they eat tadpoles, dragonfly larvae and almost everything else you are trying to encourage.

Wildlife You Can Expect

The first arrivals are usually water beetles, pond skaters and tiny flatworms, carried in on the wind or on the feet of birds. Frogs and toads will appear within a season or two, often before you have seen a single adult; their spawn is a sure sign the pond is working. Smooth newts may follow, hiding by day among stones and leaves. Dragonflies and damselflies arrive in early summer, laying eggs on submerged stems and emerging as adults on warm mornings. Hedgehogs visit for fresh water, especially during dry spells, and will happily use a shallow pebble beach or ramp. Birds will bathe, and bats may hawk for insects over the water at dusk. Leave a few stones and a log pile nearby to create damp hiding places for amphibians when they leave the pond.

Looking After Your Pond Through the Year

A wildlife pond is not a swimming pool; it should be left a little wild. In spring, remove only a little blanket weed and any dead plant material with a rake, leaving it on the edge for a day so creatures can crawl back. In summer, top up with rainwater if the level drops. In autumn, net out some fallen leaves, but leave a few to rot down naturally — they provide food for larvae. Do not empty and scrub the pond; the mud and debris at the bottom are home to countless invertebrates. In winter, never smash the ice, as the shock waves can kill frogs resting in the mud. Instead, float a pan of hot water on the surface to melt a hole for gases to escape. Every few years, thin out overgrown plants and clear a little silt, doing half the pond one year and the other half the next. With so little effort, your pond will become a year-round haven.