How to Create a Wildlife Pond in a Small Garden

Why a small pond is the best thing you can add to a garden

If you only ever do one thing for wildlife, make it a pond. Even a modest puddle-sized one — a metre and a half by a metre — will pull in more creatures than a whole border of flowering shrubs. Frogs, newts, dragonflies, damselflies, water beetles, pond skaters, and a host of insects you never knew lived in your postcode will find it. Birds will use it for bathing and drinking. Hedgehogs will stop by for a drink on a warm evening.

The good news is that a wildlife pond is cheaper and easier than most gardening projects. You do not need a pump, a filter, fish or any chemicals. You need a sunny corner, a bit of digging, a liner and some native plants. Once it is established, it largely looks after itself.

Choose a sunny spot — but not under a tree

Aim for four to six hours of direct sunlight a day. Sun warms the water, which brings on the algae and insect life that everything else feeds on, and it encourages plants to flower. A pond in deep shade will sulk and stay lifeless.

Keep it away from overhanging deciduous trees. Fallen leaves rot down and turn the water into a stagnant soup, and roots can puncture a liner. Also steer clear of the bottom of a slope where lawn fertiliser, weedkiller or dog shampoo might wash in — anything that runs off the garden ends up in the water.

Think about visibility, too. Put the pond where you can see it from a kitchen window or a favourite seat. You will spend far more time watching it than you expect, and you will spot problems early. If you have small children, either keep the pond shallow and supervise closely, or fit a sturdy metal grid just below the surface, disguised with a few stones and plants. A gently sloping edge is safer than a sheer drop and far better for wildlife anyway.

Dig it with a shelf, a deep spot and an escape route

Mark out a shape with string or a hose — curves look more natural than straight lines, but rectangles work fine in small gardens. Dig in layers:

• A shallow shelf about 20–25cm deep and 25cm wide around most of the edge. This is where marginal plants sit and where birds and frogs can stand.
• A deeper section of 60–75cm in the middle, so frogs and newts have somewhere to overwinter without the pond freezing solid.
• At least one gently sloping ramp of stones or gravel, so anything that falls in — hedgehogs especially — can climb out. Steep, slippery sides drown wildlife.

Line the hole with a layer of soft sand or old carpet underlay, then a butyl rubber liner. Allow plenty of overlap around the edges and tuck it under turf or stones so the sun does not degrade it. Fill with rainwater from a water butt if you can — tap water is full of nutrients that feed algae. Let it settle for a week or two before planting.

Plant native species and skip the fish entirely

Native plants do the heavy lifting: they oxygenate the water, shelter larvae and provide perches for emerging dragonflies. Plant in baskets of loam-based compost, not rich potting compost, which leaches nutrients. Good choices for a small pond include:

• Oxygenators: hornwort, water starwort, water milfoil — two or three baskets in a small pond.
• Marginals: marsh marigold, water forget-me-not, water mint, marsh cinquefoil, lesser spearwort, ragged robin.
• Floating: frogbit or broad-leaved pondweed, both manageable in small spaces.

Avoid the thugs. Floating pennywort, parrot's feather, water hyacinth and New Zealand pygmyweed are invasive and, in some cases, illegal to plant in the wild. Yellow flag iris and bulrush will also swamp a tiny pond.

And please, no fish. Goldfish and koi eat tadpoles, larvae and everything else you are trying to attract.

Keep the water clean without pumps or chemicals

A wildlife pond should be still. No fountain, no filter, no barley straw, no algaecide. Plants and the natural balance do the work. Expect green water in the first spring — it usually clears as plants establish and shade the surface.

Blanketweed is inevitable in a new pond. Twirl it out with a cane and leave it on the edge overnight so any trapped creatures can crawl back in. Top up with rainwater only, never tap water. Keep fertiliser, weedkiller and slug pellets well away; slug pellets kill frogs and hedgehogs, and run-off poisons the whole pond. If you must thin plants, do it in late summer or early autumn, not in spring when everything is spawning.

Let the edges grow wild and wait for the arrivals

Leave a metre of unmown grass, a log pile and a few flat stones around the pond. Frogs shelter there, newts hide under logs, and dragonfly larvae climb out onto stems to emerge as adults. Resist tidying right up to the water's edge.

The reward comes quickly. Water beetles and pond skaters fly in within days. Frogs usually appear the following spring, newts a year or two later. Dragonflies and damselflies arrive once there is structure to perch on. If you are very lucky you may find great crested newts — they are protected, so admire them from a distance and never move them. Otherwise, just keep the water clean, keep the plants native, and let the garden do the rest.