Garden Pond Advice Hub

1 Mark out the pond shape that you want

Use a length of rope, hosepipe, string between sticks, bamboo canes etc to mark out the pond shape before you start digging.

For wildlife, the pond shape is less important than the depth (remember – you need lots of shallow water), how clean the water is, and what the edges are like. That means you can make a pond that is ‘natural or ‘formal’ – it just depends on what looks good in your garden.

2 Remove the turf

It’s time to start digging! Start to dig out the turf but don’t dig down too deep. Keep the pieces of turf because you can use them round the edge of the pond to secure the liner, but don’t put them in the pond. If you do, they will almost certainly add a massive blast of polluting nutrients to the water, which will plague you for the rest of the pond’s life.

3 Dig to the right depth

It’s very easy to dig a wildlife pond too deep and end up with a miniature version of a giant open cast mine. A wildlife pond should have lots of shallow water – roughly 50% shallows, and the deep area is not more than 30 cm.

The standard advice that you need to dig down to 50  or 60cm applies only to fish ponds. The reason you’re told to do this is that the pond might freeze solid. While this might be true in northern Canada, it is not the case in the UK. The other reason – that oxygen may run out – is probably true sometimes but is not a cast iron rule.

The simple act of removing the turf can create a massive steep ‘cliff’ right at the edge of the pond. To create a gentler grass edge, you can raise a 20 to 30cm rim of turf around the edge of the pond and remove some of the soil to make the turf half the thickness. Then, place the liner under the grass edge and lay the turf on top.

4 Create shallow basins

Now the pond bottom will be at the same level as the bottom of the turf at the edge of the pond. But the real way to get shallow water in a small pond is have shallow basins.

So this is the final shape: in large parts of the pond, it hardly looks as though there’s been any digging at all. This is the right depth for pond wildlife. Tadpoles love shallows and it’s where almost all other pond wildlife is happiest. Most garden ponds are too deep for their area: if you want a half metre deep pond, or deeper, it needs to be much bigger or you end up with very steep sides.

5 Check the level

It’s important to get the pond level, otherwise some of the water will run out and you will have bare liner on one side. You’ll need a spirit level that you can put on a piece of wood that will go right across the pond.

6 Add the liner

Now the lining: it’s best if you can use underlay under the rubber liner. You can buy the underlay if you don’t have any old carpet around. Simply put down a double thick layer of the underlay, which you should be able to find at your local garden centre. Remove any stones carefully.

7 Add water

If you are patient you can wait for the pond to fill with rainwater. or you can collect rainwater in your water butts and use this. Most tapwater is not fit to use in a pond because it’s full of nutrients, which are toxic to wildlife.

Congratulations, you now have a pond!

8 Wait for wildlife

You should start to see wildlife very soon. To ensure your pond provides an unpolluted habitat for plants and animals, make sure you don’t add soil, turf or fish food. You could add some clean children’s play sand to the bottom of the pond to make it more natural looking.

There is no need to plant your pond: be patient and plants will naturally colonise your pond. If you can’t wait then only add local, native, wild sourced plants (only collected from landowners who’ve given permission).

Relax after your hard work and enjoy your garden pond.