Britain's Hidden Wetland Heritage

Ask most people to picture a British wetland and they will imagine a muddy pond or a reedbed at the edge of a nature reserve. In truth, our islands were once stitched together by a far richer patchwork: valley fens fed by lime-rich springs, sprawling lowland marshes that flooded every winter, and carr woodlands of alder and willow standing with their roots in the water. A fen is fed by groundwater and slowly accumulates peat; a marsh is dominated by grasses, rushes and sedges; a carr is the wet woodland that follows when a fen is left to scrub over. Together they formed a living sponge across the landscape.

What remains is a shadow of that. We have lost the overwhelming majority of our lowland fens and marshes — some estimates put the figure as high as 90 per cent since the seventeenth century — drained for agriculture, built over, or cut off from the rivers and springs that once fed them. The fragments that survive are among the most precious habitats in Britain, and among the most threatened.

Carbon Sinks and Flood Defences

Wetlands work hard for us, quietly. Where peat has formed over centuries, the soil is a dense store of carbon, and living Sphagnum moss keeps locking more away. Drain a fen and that bargain is broken: as the peat dries and meets the air, its carbon is released as carbon dioxide, and a habitat that was a sink becomes a source. Restoring the water table is one of the most effective things we can do — for the climate as well as for wildlife.

Wetlands also hold water. A functioning marsh behaves like a sponge, soaking up rainfall and releasing it slowly downstream, while floodplain fens and carr give a river room to spread and lose its energy. That reduces peak flows in the villages and towns below. Carr woodland does a third job too, shading watercourses and keeping them cool — increasingly valuable as summers grow hotter.

A Refuge for the Rare and Specialist

Because wetlands are so scarce, the species that depend on them are scarce too. Reedbeds shelter bitterns and marsh harriers; fen pools hold great crested newts and the rare fen raft spider. Wet meadows support marsh fritillary butterflies, while the swallowtail is now confined to the Norfolk Broads. Plants are just as exacting: fen orchid, marsh helleborine and slender sedge cling to a handful of sites, each fussy about water chemistry, water level and how the land is grazed.

Wildlife we love relies on wetlands too. Water voles burrow into soft banks, otters hunt along carr-lined rivers, and the returning cranes nest in secluded marshes. Insect life is staggering — dragonflies, damselflies and a host of specialist beetles and flies that need clean, unpolluted water.

Native Plants That Earn Their Place

You do not need a nature reserve to grow the plants of Britain's wetlands. Many native species are handsome, hardy and generous with nectar, and they settle happily into a damp corner. Among the most reliable:

• Marsh marigold — golden cups in early spring, happiest at the edge of a pond or in boggy ground.
• Ragged robin — deeply cut pink petals on damp meadow soil, loved by bees.
• Cuckooflower (lady's smock) — pale lilac flowers that feed orange-tip caterpillars.
• Meadowsweet — frothy cream heads, sweetly scented, ideal for a damp border.
• Purple loosestrife — tall magenta spires that draw in bees and butterflies through late summer.
• Bogbean — a low, creeping gem with fringed white flowers, perfect for the shallow margins of a pond.
• Water forget-me-not and water mint — modest, spreading plants that soften the water's edge and shelter tadpoles and newts.

Pair them with a native sedge or two, such as greater pond sedge or common club-rush, and you have the beginnings of a genuine wetland community rather than a decorative pond.

Recreating a Little Wetland at Home

Even a small garden can make a difference, and a wetland corner is easier than many people expect. A pond is the obvious starting point: a butyl or flexible liner, a shallow shelf for marginals, a gentle slope at one end so hedgehogs and frogs can climb out, and rainwater rather than tap water to fill it. Avoid fish, which eat the larvae and tadpoles you are trying to encourage.

If a pond is not possible, a bog garden works beautifully. Line a hollow with butyl, perforate it in a few places, backfill with soil and plant the damp-loving species above. A rain garden — a shallow planted depression that catches runoff from a downpipe or path — does the same job while easing pressure on drains. Avoid fertilisers, pesticides and peat-based compost, and never introduce invasive non-natives such as Himalayan balsam or New Zealand pygmyweed, which smother native wetland plants.

Holding On to What Remains

Britain's wetlands are still being lost — to drainage, to water abstraction, to nutrient pollution from farming and sewage, to development and to the slow drying effects of a warming climate. Healthy wetland is not a luxury; it is carbon storage, flood defence, clean water and a home for species found almost nowhere else.

That is why local wildlife trusts, wetland reserves and community groups matter — and why the smallest garden pond counts. Every patch of clean, unfertilised water adds a rung to a ladder of stepping stones across the landscape. Plant a marshy corner this autumn, let the rain fill it, and watch what arrives.