Small Really Is Enough

A pond earns its place in any garden, however tight the space. You do not need a liner, a digger or a lost weekend of digging — a half barrel, a buried butler sink, a large glazed pot or a sturdy trug will all do the job. What matters is depth. Aim for 40–45cm at the deepest point, with a surface of around 60–70cm across, and you have enough water to stay cool and stable through a hot July. That is plenty for frogs, newts, water beetles, damselflies and a cloud of insects that will in turn feed your birds.

Do not add fish. Goldfish, and even small native fish, will clear a barrel pond of tadpoles, larvae and eggs within weeks. A wildlife pond is at its best when it is left largely alone.

Choosing the Container and the Spot

If you are buying a second-hand barrel, check it has not held oil, dye or chemicals, and line it if you are unsure — a piece of butyl pond liner tucked inside does the job neatly. Timber barrels need to be kept damp so the staves stay swollen and watertight, though a slow leak is easy to live with because you will be topping up anyway.

Site your pond where it gets sun for part of the day and shade for the rest. Full sun brings algae and overheating; deep shade keeps the water cold and stops plants flowering. Keep it away from overhanging trees so you are not fishing out leaves in November, and out of any frost pocket at the bottom of the garden. Being able to see it from a kitchen window matters more than you would think — a pond you watch is a pond you learn from.

• Avoid spots that catch run-off from lawns recently treated with weedkiller or fertiliser.
• If small children use the garden, raise the container on a plinth or fit a sturdy mesh grid just below the surface.
• Place it near long grass, a log pile or a shrubby corner, so amphibians have cover on the way in and out.

Planting: Oxygenators and Natives First

Start with oxygenating plants, because they keep the water clear, mop up nutrients and give larvae somewhere to hide. Good native choices include hornwort, water starwort and spiked water milfoil — all British natives that grow happily in a small container. Aim for roughly a third of the water surface covered in submerged planting.

Then add marginals around the rim, sitting on a shelf or on stacked bricks: water forget-me-not, marsh marigold, lesser spearwort, ragged robin and flowering rush all work well in shallow water. Add one or two floating plants such as frogbit, so that by midsummer about half the surface is covered — but not all of it, because light needs to reach the oxygenators below.

Fill with rainwater from a butt wherever you can. Tap water carries nutrients and phosphate, which feeds blanketweed. If tap water is your only option, let it stand in a bucket for a day or two and use it sparingly.

Be careful what you introduce. Never add New Zealand pygmyweed, floating pennywort, water fern or parrot's feather — they will swamp a small pond and spread well beyond your garden.

Give Wildlife a Way Out

This is the detail most small ponds get wrong. Frogs, hedgehogs, beetles and thirsty birds will all end up in the water; if they cannot climb out, they drown.

• Set a ramp — a length of untreated timber or a rough piece of stone — from the water surface to the ground at an angle of no more than 45 degrees, and closer to 30 if you can manage it.
• Stack a few stones inside the pond to create a shallow shelf just below the surface, so insects and fledgling birds can clamber onto something solid.
• Leave a gentle slope of pebbles at one edge for anything that prefers to walk out rather than climb.

Check the ramp stays put through winter and does not get buried under fallen leaves.

Leave the Edges Wild

Resist the urge to tidy. Long grass, a few nettles, some dead stems and a pile of logs within a metre or two of the pond give amphibians somewhere to shelter by day and to overwinter in the mud. Leave seedheads standing for the birds and insects, and do not strim right up to the rim.

The same applies to the water itself. A pond with a few leaves in it, a little algae on the stones and no chemical treatments is a far better pond than a spotless one. Think of the whole area — water, margin and rough ground — as one habitat, not a water feature with a tidy border.

Keeping It Going Through the Year

Maintenance is minimal. Top up with rainwater during dry spells, aiming to keep the level steady rather than flooding it. In autumn, scoop out fallen leaves before they rot and turn the water black. In spring, thin the oxygenators if they have filled more than half the water — pull them out by hand rather than using a net that might catch frogspawn.

Never empty and scrub a wildlife pond. Every few years you may need to clear some silt, but do it in late autumn and leave a bucket of the old water and debris beside the pond for a day or two, so anything you have scooped out can crawl back in.

The reward comes quickly. Within a single season you will see water boatmen rowing about, damselflies laying eggs on the stems, and probably a frog or two sitting at the edge at dusk. A small patch of water, a gentle ramp and a scruffy edge — and you have a whole living community in the corner of your garden.