Why a Pond Beats Almost Anything Else You Can Do

If you only ever make one change to your garden for wildlife, make it a pond. Nothing else comes close for the sheer number of species it supports. Within a few weeks of filling a new one, you can expect water beetles, pond skaters, damselflies and the first hopeful frogs. Given a season or two, smooth newts usually find their way in too, sometimes travelling surprising distances overland from a neighbouring garden or ditch.

Best of all, a wildlife pond does not need to be big, expensive or high-tech. No pump, no filter, no fish, no fountain. A hole roughly two metres across, lined and planted with native species, will outperform a manicured ornamental pool every time. The trick is getting the shape, the position and the planting right from the start.

Choosing the Right Spot

Position is the single biggest factor in whether your pond thrives or turns into a bowl of green soup. Aim for partial shade — somewhere that gets sun for part of the day but is shaded during the hottest hours. Full sun encourages algae; deep shade suppresses the plants and leaves the water cold and lifeless.

Other things to weigh up:

• Keep it away from large trees. Falling leaves add nutrients that feed algae, and roots can puncture a liner.
• Choose ground that is roughly level, or you will spend a fortune on liner hidden above the waterline.
• Site it where you can see it from the house. You will spend far more time watching it than you expect.
• Leave a wild, undisturbed margin on at least one side — long grass, log piles and leaf litter are where frogs and newts spend most of their lives.
• Think about the slope of the ground. A gentle slope makes digging shallow shelves much easier.

If you have small children, a pond in the open where you can supervise is safer than one tucked behind a shed, and a sturdy mesh cover is a sensible precaution for the first few years.

Digging In: Depth, Shelves and Shape

Mark out an irregular shape — curvy edges look natural and give wildlife more places to shelter. Then dig in layers.

Start with a shallow shelf around at least part of the perimeter, roughly 20cm deep and 30cm wide. This is where frogs will spawn, where many marginal plants sit, and where birds and hedgehogs can drink and bathe safely. On one side, grade the shelf down into a gradual beach rather than a cliff edge. Hedgehogs, frogs, toads and even the occasional thirsty cat need an easy way out.

In the centre, aim for a depth of 60–75cm, or deeper if you have the room. That gives newts and frogs somewhere to retreat when the surface freezes, and stops the pond freezing solid in a hard winter. A pond that is 100cm deep in the middle is ideal in colder parts of the country.

Remove sharp stones and roots from the hole, then line it with a layer of soft sand or old carpet underlay before the liner goes down. Butyl or EPDM rubber lasts for decades and is far more forgiving than a rigid pre-formed shell when you are digging an irregular shape. Allow plenty of overlap around the edges, and weight it down with turf or stones while it settles.

Filling and Planting with Native Species

Fill with rainwater from a water butt if you possibly can. Tap water is not fatal, but it carries nutrients and traces of chlorine that encourage algae in a new pond. If you must use a hosepipe, let the water stand for a few days before planting.

Then plant generously, and use natives. A good basic mix includes:

• Oxygenators: hornwort and water starwort, planted in baskets or simply dropped in.
• Marginals for the shallow shelf: water forget-me-not, marsh marigold, lesser spearwort and water mint.
• Taller accents: yellow flag iris and purple loosestrife, both vigorous, so give them room.
• Boggy edge: ragged robin and soft rush, planted just outside the liner where the soil stays damp.

Steer clear of invasive species such as floating pennywort, parrot's feather and Canadian pondweed. Never introduce fish — they eat tadpoles, newt larvae and almost everything else you are trying to attract.

What Will Turn Up, and How to Help It

Common frogs usually arrive first, spawning in the shallows in late winter. Common toads, which lay long strings of spawn rather than clumps, may follow. Smooth and palmate newts typically appear in spring, and they need plenty of fine-leaved plants because females wrap each egg individually in a leaf. A pond without vegetation is a poor nursery.

Be patient about great crested newts. They are fully protected by law, so if you suspect they are present, seek advice before doing any work near the pond.

Resist the urge to tidy. Leaving the pond edges long, keeping a log pile nearby and allowing a little leaf litter to accumulate will do more for amphibians than any amount of fussing.

Looking After It Through the Year

Wildlife ponds need very little intervention. Top up with rainwater in dry spells, and clear out excess blanket weed by twirling it around a stick in late summer rather than reaching for chemicals. Remove only a third of the submerged vegetation in any one year, and leave anything you pull out on the edge for a day so creatures can crawl back in.

In autumn, net out fallen leaves or rake them from the surface before they sink. Leave the pond alone over winter, and by February you should hear the first croaking — the surest sign that your small patch of water has become a proper habitat.