Why a working field benefits from a pond

A pond on a smallholding is not a luxury. Roughly half of the UK's ponds disappeared in the last century — drained, filled and ploughed out — and those that survive are often the single richest habitat on the holding. Within a season or two of digging, a new pond in a grazing field will pull in common frogs and toads, smooth and palmate newts, dragonflies and damselflies, water beetles, and the bats and swallows that hunt them at dusk. It also gives birds, hedgehogs and small mammals a dependable drink in dry spells, which matters more with every hot summer.

The trick is to build it so that it works with the grazing round rather than against it. Get the siting right and a pond will mostly look after itself for decades.

Choosing the site: get this right and the rest follows

The instinct is to dig at the lowest, wettest corner of the field. Resist it. Low ground collects everything washing off the land above — nutrients, silt, muck, wormer residues — and you will end up with a green soup of algae and blanketweed instead of clear water.

• Slope, not sump. Aim for a gently sloping site in open sun, ideally with a small catchment above it but no obvious channel running into it.
• Keep clear of trees and hedges. Ten to fifteen metres at minimum. Leaves raise the nutrient load and shade kills the submerged plants that keep water clear.
• Watch for drains and ditches. Old field drains, culverts and watercourses should be avoided — and any work to a ditch or stream needs consent from the environmental regulator first.
• Test the soil before you commit. Dig a spade-deep hole in early spring, fill it with water, and see how it holds overnight. Heavy clay will seal itself; sand or gravel will need a butyl liner or a puddled clay layer.
• Check for protected species. Great crested newts and their breeding ponds are strictly protected, so if they are on site, works must be licensed and timed correctly.

Shape, depth and size

Think like an amphibian, not a landscape gardener. Irregular outlines with a wavy margin give more edge, and edge is where the life is. Build in a substantial shallow shelf — 20 to 30 cm deep — around at least half the perimeter for marginal plants, spawning and basking, then drop to a deeper basin of around 1.5 metres in the middle. That deep water stays cool in summer and gives frogs and newts somewhere to overwinter below the ice.

Slope the sides gently, roughly one in three, so wildlife can climb out and any child who ends up in it can simply walk out. Even a pond of three metres by four will be colonised within a year; twenty square metres or more is genuinely valuable. Keep the spoil nearby — a low bank of subsoil, capped with turf, makes a fine hibernaculum for amphibians and a basking spot for reptiles.

Fencing, buffer strips and stock water

Livestock and ponds are a poor mix. Cattle and horses will wade in to drink, puddle the margins, dung in the water and, on soft ground, occasionally get stuck or drown. Sheep do less damage but still graze off the marginal plants and break the bank down.

Fence the pond off with a permanent stock fence or a well-earthed electric line, set back three metres or more. That gap becomes a buffer strip of rough grass and wildflowers, which filters runoff before it reaches the water. Crucially, provide an alternative: a trough, or a fenced drinking point on a hard-standing. If stock have to choose between a trough and a pond, they will usually choose the trough — as long as it is close to where they already gather and there is shade nearby. Never leave a fence line that funnels animals into a tight corner against the water.

Children, neighbours and staying safe

A pond in a field where children play or walk needs honest thought. The safest design is also the best for wildlife: shallow, gently shelving margins with no straight drop, so anyone who goes in can get straight out. Sited fifteen metres from a hedge and clearly visible from the house, it stays in view. A stock-proof fence with a self-closing gate keeps toddlers out while still letting you in for maintenance. If you farm on a public footpath, keep the pond well back from the line and check your public liability cover with your insurer.

Planting, stocking and yearly care

Do not overplant. Let the pond find its own balance for the first year, then add native species from a reputable UK nursery: marsh marigold, water forget-me-not, brooklime, purple loosestrife, yellow flag iris, water mint and hornwort for oxygen. Avoid anything invasive — floating pennywort, water fern, parrot's feather and Australian swamp stonecrop are all illegal to plant in the wild and a nightmare to remove. Never introduce fish: they eat spawn and tadpoles and cloud the water. Never move spawn or plants between ponds either, as disease and invasive species travel with them.

Once or twice a year, in late summer, cut back a third of the marginal growth and rake out excess submerged weed, leaving the cuttings on the bank for a day so creatures can crawl back. Top up in drought with rainwater from a butt, never tap water, and keep fertiliser and spray drift well away from the catchment. Check the fence each autumn. Then leave it alone — the best wildlife ponds are the ones people fuss over least.