Creating a Container Water Feature for Small Gardens

Why a Container Pond Suits a Small Space

Not every garden can spare the space for a pond, but almost every patio can spare a corner. A container water feature offers the two things a full-size pond gives you in miniature: the soft sound of moving water and a genuine habitat for wildlife. A half barrel planted with a few aquatics, topped up with rainwater, will draw bees for a drink, dragonflies on the hunt and, if you are lucky, a frog or two. Because it sits above ground, you can move it, drain it or rearrange it whenever you fancy a change. No digging, no liner to wrestle into a hole, and not a single square metre of lawn sacrificed.

Choosing the Right Container and Spot

Aim for a container at least 45cm (18in) across and 30cm (12in) deep. Depth matters more than width: a deeper pot stays cooler in summer and is slower to freeze in winter, which gives plants and overwintering creatures a much better chance. Whatever you choose must hold water, so seal any drainage hole with silicone or a scrap of butyl liner.

• Half barrel — the classic. New oak barrels leak for a week or two until the wood swells, so soak them well first.
• Glazed pot — choose frost-proof ceramic in a colour that suits your patio, and bring it under cover in hard winters.
• Old tin bath, stone trough or zinc planter — full of character, and metal or plastic is handy on a balcony where weight matters.

Stand it on level, firm ground where it receives four to six hours of sun a day — enough to coax a water lily into flower. Morning sun with a little afternoon shade is ideal, as it keeps the water cooler in a heatwave. Keep it clear of overhanging trees that will shower it with leaves, and away from the path of footballs and boisterous dogs.

Setting It Up in an Afternoon

Use rainwater from a water butt if you can. Tap water carries nutrients and chlorine that feed algae, so if you must use it, let it stand for a day or two first. Then:

• Plant each aquatic in a basket of aquatic compost, topped with gravel to stop it clouding the water. Ordinary garden soil is far too rich and will turn everything green.
• Lower the baskets in, then fill gently to within 5cm of the rim, pouring onto a saucer or a sheet of bubble wrap so nothing is disturbed.
• Add a small solar fountain if you would like the sound of trickling water. Gentle movement also discourages mosquitoes from laying eggs.

If the water looks cloudy at first, leave it be. It usually clears within a week.

Plants for a Small Pond

You need three types: oxygenators, marginals and something floating. Together they shade the water, use up nutrients and give wildlife somewhere to hide.

• Oxygenators — hornwort and water starwort need no planting at all; simply drop a handful in. They are the workhorses of clear water.
• Marginals — water mint, marsh marigold and dwarf reed sit in baskets with their crowns just below the surface. Water mint smells wonderful when you brush past it.
• Floating plants — frogbit and water soldier drift on the surface. Both spread quickly in a warm summer, so thin them as needed.
• Dwarf water lily — a compact cultivar in a 5-litre basket will reward a sunny spot with a few blooms. Full-size lilies will swamp a small container within a season.

Never take plants from a wild pond or stream. You risk importing duckweed, blanket weed and disease, and digging up wild plants is often illegal.

A Home for Wildlife

Give creatures a way in and out. A sloping ramp of stones, or a piece of weathered wood leaning from the patio into the water, lets frogs, hedgehogs and beetles climb out if they fall in — without one, they can drown. Leave a few flat pebbles just above the waterline so bees and butterflies have somewhere safe to drink. Children adore a container pond, and it makes a lovely wet-afternoon project: building a little pebble beach, planting the baskets, or setting a ring of flat stones around the base. Keep it simple and let them get their hands wet.

Keeping the Water Clear Through the Year

Little and often is the secret. Top up with rainwater whenever the level drops — a hot week can lose several centimetres. Net out fallen leaves before they sink and rot. If the water turns green in spring, be patient: once the plants grow and shade the surface, it usually clears within a fortnight. Barley straw extract helps in stubborn cases, and a handful of extra oxygenators does more good than any chemical.

Once a year, in late spring, thin the oxygenators so roughly a third of the water is clear of them, and divide any marginal that has outgrown its basket. Feed water lilies with an aquatic tablet in May and again in July. Never empty and scrub the container — that destroys the tiny creatures which keep the water balanced.

In winter, move glazed pots to a sheltered spot. If the surface freezes, do not smash the ice, which can harm overwintering wildlife and crack the pot. Rest a ball or a pan of hot water on the surface and let it melt through gently.

By spring you will have a small patch of water that hums with life and sounds lovely on a quiet afternoon. Few garden features repay so little effort so generously.