Where should a garden pond go?

Put the pond where you can see it, on ground that is already close to level, with part of the surface in the sun and part out of it. Then check what is under the lawn before anyone starts digging.

Sun and shade

The RHS construction guide says a pond should sit in sun or partial shade. Some shade slows algae. At least half the surface should still be in full sun. The wildlife-pond page says the same thing from the animals' side: shade suits many plants, but a sunny patch warms the water in spring, which is when frogs and toads spawn.

Full sun all day is the setup most likely to turn the water green. Full shade is a poor place for oxygenating plants. Green water is much easier to avoid here than to cure in July.

Trees, roots and leaves

Avoid big tree roots. They make the dig miserable and they can lift a liner later. Leaves are a separate problem. A few in the water are not a crisis, but a pond under a deciduous tree fills with them every October. The RHS October notes say to net the pond then. See winter care.

What is under the garden

The RHS says that for a large or deep pond it is worth checking for buried utilities. That means electric cables, water pipes, gas and drains. A pond should not sit on top of a drain you may need to excavate, and a pump cable should not be an excuse to dig blindly. Ask for plans or a utility search before the first spadeful. LinesearchbeforeUdig is the UK place asset owners use for that kind of search.

The hole also has to hold water without flooding the house. Do not cut a pond into the only path that takes surface water away from a wall. If the garden has a septic tank or a soakaway, keep the pond and its overflow away from them. Rowanspring separates drainage fields from rainwater soakaways, which is a different job, but the same "know what is under the lawn" habit.

Children, sightlines and mowers

If young children live in the house or visit, the site is a safety decision, not a styling one. RoSPA's starting point is to restrict access. A pond tucked behind a shed, where you cannot see a child from the kitchen, is a worse site than one you look at every time you fill the kettle. Read pond safety for children before you fill anything.

The RHS also wants a wildlife pond somewhere you can sit and watch it, and somewhere fairly quiet. Those two aims can both be true: visible from the house, not beside a goal or a trampoline.

A robot mower does not understand a beach. Give it a boundary well back from the edge, and a hard edge it cannot climb. Gladeburn covers robot mowers. Plankley covers the digging, edging and paving once you know the outline.

Electricity

If the pond needs a pump or a filter, the RHS says the supply must be installed by a qualified electrician. Plan the cable route while the garden is still a drawing, not after the liner is in. Details are on the electrics page.

Can I put a pond under a tree?

You can, but roots and autumn leaves are the usual reasons not to. A little shade from a fence or a shrub is more useful than a canopy that drops a barrow of leaves.

Does the ground have to be level?

The RHS says the ground should be level, with no big roots or other obstructions. A pond on a slope wants a lot of spoil moved to one side, and the water will still find a level of its own.