Why reeds belong in a British garden pond

There is a stubborn myth that reeds will ruin a pond. In practice, the trouble is never the reeds themselves but reeds left without a plan. Give them a defined space and a yearly trim, and they become one of the hardest-working features of any wildlife pond — filtering water, sheltering amphibians and giving dragonflies somewhere to climb out of the water and dry their wings.

It helps to know what we mean by "reed". Britain's true reed is common reed, a tall grass with feathery seed heads that turns straw-gold in autumn. Reedmace — the one with the familiar brown sausage on a stick, often wrongly called bulrush — is a different plant altogether and noticeably more thuggish. Both are useful, but reedmace needs far stricter boundaries.

The wildlife that moves in within a season

Plant a clump of reeds in spring and the response is often quick. The dense stems create a sheltered microclimate at the water's edge, a few degrees warmer than the open water and out of the wind, which is exactly what small creatures need.

• Amphibians: frogs and toads use reed beds as cover between spawning and leaving the pond, and newts shelter among the stems during the day.
• Dragonflies and damselflies: their nymphs climb emergent stems to emerge as adults, leaving behind the ghostly empty cases you will find in early summer.
• Birds: moorhens and coots nest in the shelter of a good clump, and reed buntings will perch and feed on the seed heads if you leave them standing through winter.
• Insects: hoverflies, bees and beetles visit the flowers, whilst the hollow stems are used by overwintering invertebrates.

Reeds also soften the pond's edges, hiding the liner and giving the whole thing a settled, established look from the very first season.

Reeds as a living filter — and their limits

Reeds take up nitrogen and phosphorus from the water as they grow, and their roots support a film of bacteria that helps break down waste. Their stems slow the flow of water, letting suspended silt settle out rather than clouding the pond.

But be realistic about the scale. A few baskets of reeds in a small garden pond will not solve a duck-pond problem. Plants remove nutrients most effectively when you cut the stems and take them away, because the nutrients are locked inside the plant tissue. Leave the cuttings in the water and you have simply recycled them. Think of reeds as one part of a balanced pond alongside oxygenators, submerged plants and sensible feeding of any fish.

Choosing and planting the right plants

Stick to British natives where you can. Good options include common reed, reed sweet-grass, lesser reedmace and soft rush, along with sedges and flowering rush for variety. These are adapted to our climate and will not escape to cause trouble in the wider countryside the way some non-native aquatics can.

Plant in spring, when the water is warming. Use aquatic baskets lined with hessian and filled with heavy loam or a low-nutrient aquatic compost — not rich multipurpose compost, which leaks nutrients into the water and feeds algae. Top each basket with a generous layer of gravel to stop fish and birds rooting about.

• Shallow shelf plants: soft rush, sedges and flowering rush, sitting in 5–15cm (2–6in) of water.
• Mid-depth marginals: common reed and reed sweet-grass in 15–30cm (6–12in).
• Deeper water: reedmace at 30–45cm (12–18in), always contained.

Space clumps roughly 30–45cm (12–18in) apart so they fill in without immediately crowding each other. If your pond is lined, sink a rigid barrier or a wide basket into the planting shelf, because vigorous rhizomes can creep across a liner and, in the case of reedmace, pierce it.

Keeping reeds in check

A little routine work in late winter keeps everything civilised.

• Cut back in February or early March, before new growth starts but after birds and insects have finished with the old stems. Cut just above water level.
• Remove every cutting. This is the whole point — it exports the nutrients the plants have absorbed.
• Divide congested baskets every two to three years in spring, splitting them with a sharp spade and replanting the healthiest sections.
• Watch the spread. Pull or fork out any clump that has crept beyond its allotted area, and remove reedmace seedlings promptly — they colonise bare mud surprisingly fast.
• Leave a few seed heads for the birds and a touch of structure in the winter garden, but only where it will not spread.

Getting the balance right

As a rough guide, aim for marginals to cover around a quarter to a third of the water's surface, leaving the rest open. Open water matters: it is where frogs spawn, where birds bathe and where dragonflies patrol. A pond entirely filled with reeds quickly becomes a boggy, oxygen-poor marsh, and the wildlife that made it special moves on.

Get that balance right and reeds become the backbone of your pond — quietly cleaning the water, housing a small colony of creatures and giving you something beautiful to watch on a still summer evening. A clump with boundaries is not a problem. It is the best habitat you can offer.