How to build a wildlife pond

Inspired by a helpful YouTube guide. This walk-through draws on the popular video "Step By Step How To Build A Wildlife Pond For Your Garden Or Allotment" from the Simplify Gardening channel, which lays out the whole process in clear stages and explains why each step matters for the long-term health of the pond. Well worth watching before you pick up a spade — the advice on marginal shelves alone will save you a few headaches later.

1. Choose the right spot

Full sun to partial shade is the sweet spot. Six hours of sun a day encourages aquatic plants and keeps the water alive without cooking it. Avoid sitting the pond directly under a large deciduous tree — the leaf fall in autumn will rot in the water and affect the oxygen levels, which is the opposite of what you want.

Stay clear of utility runs where you can. A quick call to Dial Before You Dig is sensible if you are unsure where pipes or cables sit. Ground conditions matter too. Clay-heavy soil holds itself well; sandy or very stony ground is harder work and you may need more liner material for safety.

2. Mark out the shape and depth

Use a length of hosepipe or rope to define the outline on the grass. Organic, kidney-like shapes look better than circles or squares, and they give you more surface area for the same footprint. Step back and look at it from an upstairs window if you can — always looks different from above.

A wildlife pond needs at least two distinct depths. A shallow marginal shelf of around 15–20 cm near the edge lets amphibians get in and out easily. Then the main body should drop to 60–75 cm at its deepest point so the pond does not freeze solid in a hard winter. Mark these zones with canes while you plan.

3. Dig the pond

Start from the shallow end and work inward. Slice out the turf in sections and keep it to one side — you can use it to help bed in the edges later. Dig the marginal shelf first, then step the sides down in stages to the full depth at the centre.

Aim for sloping sides rather than vertical drops; this makes it far easier to fit the liner without creasing, and gives wildlife a gentler route out of the water. Remove all sharp stones and tree roots from the base and sides. One overlooked pebble can puncture a liner under the weight of water, so this part is worth taking slowly.

4. Fit the underlay and liner

Before the liner goes in, cover every surface with a layer of soft underlay — purpose-made pond underlay, old carpet, or 5 cm of damp sand all work. It cushions the liner against anything you missed in the soil.

Drape the butyl or EPDM rubber liner loosely over the hole — do not pull it tight. Let the weight of water do the shaping. A generous overlap of at least 30 cm all round is the minimum. Pleat the liner neatly around corners rather than cutting it to shape; cuts create future leak points.

5. Fill slowly and fold the liner

Start filling with a garden hose. As the water rises, walk around the edge and tuck, fold, and press the liner into the contours. The water weight is doing most of the work, but your hands guide the liner flat rather than letting it bunch. Mind you, this takes patience. Rushing it leaves unsightly wrinkles and can stress the liner near the edges.

Stop when the water is around two thirds full, then fold and trim the excess liner leaving that 30 cm overlap all round. Tuck it under the turf and any edging stones. Do not trim it flush with the edge — you lose that safety margin if the liner ever needs adjusting.

6. Create a wildlife-friendly edge

The edge of the pond is where most of the wildlife action happens. Lay flat stones, logs, or gravel at one shallow end to create a gradual beach — this is how hedgehogs, frogs, and birds will drink and the frogs will climb out after spawning.

Turf overhanging the edge slightly is fine where it naturally falls that way. Avoid sharp vertical edges of stone all the way round; anything that cannot scramble out will drown. A small ramp of large cobbles graded from the shallow shelf to just above water level is ideal.

7. Plant and wait

Native plants are the ones to go for. Marginal plants like marsh marigold (Caltha palustris), water mint, and yellow flag iris go on the shallow shelf in baskets. Submerged oxygenators like hornwort and water starwort go in the deeper zone — these are the plants that actually keep the water clear.

Do not add fish if you want amphibians. Fish eat tadpoles, dragonfly larvae, and much of the wildlife you are trying to attract. That said, it is your garden, but a wildlife pond is really a fish-free pond. Let the water settle for a couple of weeks before planting if you are using tap water; it will naturally lose the chlorine and come to ambient temperature. Wildlife will find the pond on their own — you do not need to introduce frogs or newts.

When to call a handyman

If you need ground-level changes to make the pond work — levelling a sloped lawn, lifting heavy slabs to rearrange the surrounding area, or building a raised or semi-raised pond above ground level — that is the kind of practical groundwork Richard can help with. The digging itself is manageable for most people with a decent spade and a clear weekend.