A Pond in an Orchard: an Old Idea, Made Useful Again

Old orchards and old ponds belong together. Before modern irrigation and mains water, most working orchards had some form of dipping pond or dew pond at the bottom of the slope — somewhere to water a horse, soak a hurdle, or simply catch the run-off from the field above. Many were filled in during the twentieth century, and the orchards that survived lost a good deal of their life with them. Reinstating one is a practical, generous act: it costs a weekend of digging and returns frogs, dragonflies and swallows for decades.

The orchard itself does much of the work already. Long, unmown grass, mossy trunks and fallen fruit have created a low-input, undisturbed floor that is unusually rich in beetles, slugs and fly larvae. All the pond has to do is add water, and the food chain assembles itself.

Siting and Shaping the Pond

Choose the sunniest open patch you can spare, ideally with five or six hours of direct light in summer. Sun warms the water, warms the tadpoles and lets the marginal plants flower properly. Some shade at one end is no bad thing, but a pond in full canopy will sulk.

Keep well clear of your trees. Fruit tree roots run at least as far as the canopy and often further, and a shallow pond dug into that root zone will be invaded within a season. Leave three to four metres between the water's edge and the nearest trunk, and consider the leaf fall too: a deep drift of apple leaves in October will rot down and foul the water if it all lands in one corner.

A gently sloping profile is the single most valuable design decision. Aim for:

• A shallow beach at one end, no more than 5–10cm deep and 60cm wide, so fledglings, hedgehogs and frogs can walk in and out without a scramble.
• A marginal shelf at 20–25cm deep, roughly 30cm wide, for the plants that do the filtering and hiding.
• A deepest point of 60–90cm, which allows wildlife to escape frost and herons, and gives the pond some thermal stability through a hot July.

Two metres by three is the smallest size worth building. Anything smaller will swing from green soup to dried mud in a single season. If the ground falls away, use that fall to your advantage: a bank on the downhill side gives you depth without excavation, and a natural-looking overflow into a boggy margin.

Lining and Edging in Keeping with the Estate

Where the subsoil is heavy clay, puddled clay will hold water for a lifetime and looks entirely of its place, though it demands patience to lay. For most of us, a butyl liner with a protective underlay of old carpet or geotextile is the reliable route. Buy more than you think you need; a pond with generous overlap is easier to edge convincingly.

The finished job stands or falls on the hiding of that edge. Nothing looks more municipal than a black rubber rim. Fold the liner back under itself, then break the line with whatever the estate already uses — weathered brick, local stone, a turf lip overhanging the water, or a shallow gravel beach where visitors and wildlife will naturally approach. A couple of half-submerged logs and a stone pile at one corner will give newts somewhere to hide and dragonflies somewhere to bask.

Do not put fish in it. Goldfish and carp will clear the invertebrates, eat the spawn and turn clear water cloudy within a summer. A wildlife pond is a different thing altogether, and better for it.

Planting with Native Species

Plant in the first spring, but lightly. Aim for no more than a third of the water's surface covered in the first year; the pond needs light to establish its own balance of algae, daphnia and insect life. Use hessian sacks or open baskets, or plant bare-rooted straight into the marginal shelf.

Reliable natives for a British orchard pond include marsh marigold, water forget-me-not, water mint, gypsywort and the smaller sedges. Yellow flag iris and purple loosestrife are lovely but thuggish in a small pond, so plant them at the far end where they can spread. For underwater oxygenators, hornwort and water starwort are vigorous and useful; common water crowfoot is prettier and less rampant.

There is a firm list of plants to avoid, all of them invasive and some illegal to plant in the wild: floating pennywort, water fern, parrot's feather and New Zealand pygmyweed. Buy from a supplier who can name the provenance of every plant, and never tip an aquarium into a pond.

Who Will Come, and What Brings Them

Frogs usually arrive first, often within a season, followed by smooth and palmate newts. Dragonflies hunt widely and will find a new pond within a year or two — expect common darters and emperors to patrol from midsummer, with azure and blue-tailed damselflies in the margins. Swallows and house martins will hawk the insects above the water, and a song thrush will work the damp edge for snails.

What makes the difference is the surrounding structure, not the water alone. Leave a patch of long grass and a pile of old apple prunings beside the pond. Never spray the orchard within ten metres of the water, and leave the fallen fruit in one corner. Bats will come at dusk to feed on the midges, and a hedgehog will come to drink at the shallow beach if it can reach it through the grass.

Keeping It in Order Through the Year

A wildlife pond needs very little, and most of that is restraint. Rake a portion of autumn leaves off the surface, but leave a few — they feed the invertebrates that feed everything else. In late winter, clear about a third of the waterweed with a rake and leave it on the bank overnight so anything caught can crawl back. Never clear the whole pond, and never in spring or summer.

Keep fertiliser, lime and bonfire ash well away, and let the grass grow long on at least one side. The first year will look raw and rather empty; the second will look as though the pond has always been there. That, in the end, is the standard for any addition to a historic orchard.