Creating a Wildlife-Friendly Pond in a Small Garden

Why a Small Pond Punches Above Its Weight

Few garden features repay the effort like a pond. Within weeks of filling, pond skaters, water boatmen and diving beetles appear as if from nowhere, hitching a lift on damp feathers and muddy feet. Damselflies are usually next — the large red and the azure are the keenest colonisers — followed by dragonflies such as the common darter, which will patrol a pond barely a metre across. Then comes the real prize: common frogs, and in many gardens smooth newts, quietly moving in from neighbouring plots.

You do not need a landscaper, a liner the size of a tennis court or a pump. What you do need is water that stays clean, a depth that does not freeze solid, a gentle way in and out for anything that falls in, and plants that do some of the work for you.

Siting It and Getting the Depth Right

Choose a spot that gets sun for at least half the day. Warm water means more insect life, and dragonflies will not linger over a chilly, shaded pond. A little dappled shade in the afternoon is fine; deep shade under a tree is not, partly because of the leaves that will fall in and rot, and partly because the water will stay cold.

Avoid the lowest corner of the garden, where run-off from the lawn will arrive carrying fertiliser and weedkiller. Both are disastrous for amphibians — frog skin is permeable, and slug pellets based on metaldehyde are particularly harmful. Keep the pond well away from anywhere you spray, and encourage the slugs naturally instead.

For depth, aim for around 45–60cm at the deepest point. That is enough to give frogs and newts somewhere to sit through a hard frost without the whole pond turning to a solid block of ice. Anything shallower than about 30cm may freeze right through, which the insects will survive but overwintering tadpoles and frogs often will not.

Starting Small: Bowls, Tubs and Sinks

A buried washing-up bowl — roughly ten litres — genuinely will attract insects, and a dragonfly may well stop by. Frogs will use it through the summer, though it is too small to be a reliable home through winter, and it needs topping up in dry spells.

If you can find room for something in the region of 60–100 litres, your odds improve enormously. An old butler sink, a half-barrel, a rigid pre-formed liner or a sturdy trug all work. Dig the hole so the rim sits just below the level of the surrounding soil, then bring turf, soil and stones up to one side to form a shallow entry slope. Keep a few centimetres of the opposite rim proud of the ground so that rainwater from uphill runs past rather than pouring in.

Fill it with rainwater from a butt wherever possible. Tap water carries nutrients and trace chemicals that encourage algae; if you must use it, let it stand for a day first and expect a green flush in the first few weeks, which usually settles once plants establish.

Native Plants That Earn Their Keep

Plants shade the water, use up nutrients that would otherwise feed algae, and give creatures somewhere to hide, hunt and lay eggs. Stick to British natives and plant in baskets of heavy loam rather than multipurpose compost, which is too rich.

• Hornwort and water starwort — submerged oxygenators that mop up nutrients and give tadpoles and newt larvae cover.
• Marsh marigold — early nectar for bees and hoverflies just as they emerge in spring.
• Water forget-me-not and brooklime — low edge plants, ideal basking and hiding spots for young frogs.
• Water mint, ragged robin and purple loosestrife — nectar and vertical stems that dragonfly nymphs climb when they are ready to emerge.
• Yellow flag iris — handsome structure at the back, though it needs dividing every few years.

Avoid the thugs: floating pennywort, parrot's feather, water fern and New Zealand pygmyweed will smother a small pond and are illegal to plant in the wild. Never take plants or spawn from another pond, however tempting — disease and invasive species travel that way. Buy from a reputable aquatic nursery instead.

Edges, Ramps and Escape Routes

Most small creatures that drown in garden ponds do so because they cannot climb out, not because they cannot swim. Hedgehogs, froglets, beetles and even the occasional fledgling all need a route to dry land. A shallow stone beach on one side, a rough plank angled into the water, or a fold of turf overhanging the edge will do the job. Check any ramp is not slippery with algae by midsummer.

Leave a log pile and a stone heap within a metre or two of the pond. Newts spend most of the year on land, sheltering in damp crevices, and they need that cover to move between ponds. Resist the urge to add fish — even a few goldfish will clear a small pond of everything else.

A Simple Year of Care

Maintenance is mostly about doing less, at the right time.

• Spring: thin blanketweed and duckweed with a stick or net, and leave what you remove on the pond edge for a day so anything caught up can crawl back.
• Late spring: cut back old stems and seed heads, rather than tidying in autumn — the hollow stems are winter shelter for insects.
• Autumn: net out some fallen leaves, but leave a few. Never empty and scrub the pond; the silt at the bottom is where frogs and newts overwinter.
• Winter: do not smash ice, as the shock can injure creatures beneath. Rest a pan of hot water on the surface instead if you need to open a hole.

Keep the pond topped up through dry spells, avoid pesticides anywhere nearby, and leave the surrounding planting a little untidy. Within a year or two you will have a patch of water that hums, croaks and glints with dragonflies — a small wilderness, right outside the back door.