Fens are areas of marsh and open water. Tall sedges and reeds grow there with other water-loving plants. They support many species of bird and insect including butterflies and dragonflies. Fenland was once most commonly found in East Anglia.


In the past, the local economy of fenland in East Anglia depended on peat and fen plants. Peat turf was dug by hand and used as fuel. Reeds were cut and harvested for thatch for barns and houses. Sedge was used for livestock bedding, and willow was used for wicker baskets or eel traps.


Fens are waterlogged areas 'fed' by an alkaline water source. The vegetation is a mosaic of sedge and reedbeds and damp 'fen' meadows, intersected by drainage ditches, streams and open areas of water. As the plant litter gradually decomposes, a rich dark peat is formed.

Where the build of peat is raised above the water table, and dries out for part of the year, shrubs and trees such as willow and alder colonise the area and woodland 'Carr' communities develop.

Habitat for wildlife

Plants found in managed fen include:

  • ragged robin (Lychnis flos-cucculi)
  • milk parsley (Peucedanum palustre)
  • great fen-sedge (Cladium mariscus)
  • meadowsweet (Filipendula ulmaria)
  • water crowfoot (Ranunculus aquatilis)
  • marsh helleborine (Epipactus palustris)

These support many wetland bird species and insects. Butterflies such as the brimstone (Gonepteryx rhamni), ringlet (Aphantopus hyderantus) and meadow brown (Maniola jurtina) are some of the most common. The beautiful but rare swallowtail (Papilio machaon) butterfly may be seen in Strumpshaw Fen in Norfolk.

Habitat loss

The history of the fens, as with most wetlands, is linked to the reclamation of land for agricultural purposes. Although the fens were first drained in Roman times, it was not until the 17th century that water was pumped away from vast areas of land. As this practice continued, the fens changed from wetlands to the dry arable land that now dominates much of East Anglia. An estimated (EN) 90% of East Anglian fenland has been lost since 1934.

Managing and restoring fens

Winter grazing by cattle or horses helps to control scrub and prevent fens from turning into woodland. In other areas, reeds are harvested and willow is pollarded or coppiced. Ditches and wider waterways are also cleared or dredged to prevent them from clogging and silting up.

The largest area of natural fenland can still be found in East Anglia. Wicken Fen, near Cambridge, has been a nature reserve owned and managed by the National Trust since 1899.

The Great Fen Project in Cambridgeshire is a partnership between the Wildlife Trust BCN, the Environment Agency, Huntingdonshire District Council, the Middle Level Commissioners and Natural England. Its aim is to create a huge wetland area (3,700 hectares) with a mosaic of different habitats. By restoring farmland, the project will connect and enlarge two National Nature Reserves, Woodwalton Fen and Holme Fen.

Find out more on the Great Fen Project website

Smaller areas may be found in other parts of the country, for example, Ham Fen in Kent and Cors Erddreiniog on Anglesey.

Fens in the Museum's Wildlife Garden

The areas of fen in the Wildlife Garden include:

  • marsh fern (Thelypteris palustris)
  • common reed (Phragmites australis)
  • sedges

There are also tall herbs such as:

  • meadowsweet
  • purple loosestrife (Lythrum salicaria)
  • yellow loosestrife (Lysimachia vulgaris)
  • great willowherb (Epilobium hirsutum)

A damp ditch creates an ideal habitat for frogs.

Fens in your garden

Many fen plants will grow alongside ponds and in marshy areas, providing nectar for bees, butterflies and other insects. Purple loosestrife is a favourite plant for bees including bumblebees.

Wildlife Garden blog


Keep up to date with what’s happening in the Museum’s Wildlife Garden and discover some of the latest sightings in this tranquil haven.

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