Priya Mehta
Start with the right spot
Even a pond no bigger than a dining table can transform a small garden. Frogs, damselflies, bathing sparrows and the odd hedgehog will all find it, provided you put it in the right place. Aim for a spot in sun for at least half the day, since most pond plants and insect larvae need warmth. In a very small garden, though, avoid the corner that bakes from dawn until dusk — shallow water overheats quickly and turns green.
Keep the pond clear of overhanging trees and shrubs. Fallen leaves rot down and feed algae, and thirsty roots can damage a liner. A position you can see from a kitchen window is worth choosing deliberately: you will notice far more of the comings and goings. If you have toddlers, either site the pond where you can supervise or plan a raised design from the outset. Check the ground is reasonably level, too — a pond on a slope needs one edge built up, and any wobble shows for ever as a crooked waterline.
Size, depth and shaping
A surface area of around one to two square metres is ample — roughly 1.5 metres by 1 metre. Depth matters as much as width, because it gives creatures somewhere to retreat when the weather turns. Build in three zones:
- Deep water: 60–75cm at the centre, so frogs and newts can overwinter in the silt and the pond does not freeze solid.
- Marginal shelves: 20–30cm deep around the edges for rushes, marigolds and other plants that like their roots wet.
- Shallow ledges: 5–10cm of water over a gentle slope, giving birds, bees and hoverflies a safe place to drink and bathe.
Butyl rubber liner gives the most flexibility in an awkward shape, whilst a preformed rigid liner is quicker to keep tidy. In the tiniest spaces, a half-barrel, an old sink or even a buried washing-up bowl works well — sink it to the rim, add a ramp and plant it up. Skip fish in a wildlife pond; even a few goldfish will make short work of tadpoles and insect larvae.
Keep it safe for wildlife and people
Steep, slippery sides trap frogs, newts and hedgehogs. Give them a way out: a sloping gravel beach at one end, a stack of stones breaking the surface, or a piece of untreated timber resting in the water as a ramp. A textured ramp works far better than a smooth one.
Where young children are around, fit a rigid mesh cover just below the surface, or fence the pond until they are older. Never fill a new pond with tap water if you can avoid it — it is full of nutrients that fuel algae. Rainwater from a butt is ideal, so a spare butt kept for topping up is money well spent.
Planting for shelter and colour
Plants do the heavy lifting in a wildlife pond: they shelter larvae, shade the water and soften the edges. Choose British natives where you can, and plant in baskets of ordinary garden soil topped with gravel, which keeps the water clear.
- Marginals: marsh marigold, water forget-me-not, brooklime, water mint, lesser spearwort and flowering rush.
- Oxygenators: hornwort and water starwort, which keep the water clear and give tadpoles cover.
- Floating leaves: a single small water lily in a large barrel, or frogbit in a tiny pond.
Steer clear of invasive non-natives such as floating pennywort, water fern and New Zealand pygmyweed. They spread rapidly and will quickly smother a small pond. Never take plants or frogspawn from the wild either; buy from a reputable aquatic nursery and let wildlife arrive on its own.
Gentle maintenance through the year
A wildlife pond should be left a little untidy. Resist clearing it in autumn: seed heads and hollow stems give insects somewhere to overwinter, and frogs bury themselves in the silt at the bottom. Cut back excess growth in late spring instead, once the frosts have passed.
In summer, thin oxygenators if they cover more than half the surface, but leave the cuttings on the side for a day so creatures can crawl back in. Scoop out fallen leaves before they sink, and top up with rainwater during dry spells. If the water turns green, it usually means too much light or too many nutrients — add more marginal plants, check for run-off from a lawn or patio, and be patient, as new ponds settle within a season or two.
What you can expect to see
Frogs and newts usually arrive first, sometimes within weeks. Damselflies and dragonflies follow in the first summer, laying eggs on submerged stems. Birds will use the shallow edge to drink and bathe, hedgehogs may visit for a drink, and bats will hunt insects above the surface at dusk.
Not every garden gets the full cast, and that is fine. A small pond in a modest plot is still one of the most generous things you can do for British wildlife — and it will reward you with something new to watch almost every day of the year.
