Mud walls, made from the clay subsoil which overlays the brick clay of the area, are a feature of  the Cambridgeshire town of  Whittlesey and the nearby village of Eastrea.  These walls were created as boundary walls following the introduction in 1784 of a brick tax to pay for onging wars against the American Colonies.  The tax was repealed in 1850, but 26 mud walls can still be found in Whittlesey.

Traditionally the walls are thatched using wheat, Triticum aestivum, but alternative thatches are  sometimes used.

The best known and most easily seen mud wall, shown here, is that at West End in Whittlesey.  Being near a busy road used by lots of lorries and other heavy vehicles this suffers by getting splash-back which washes mud off the face of the wall in wet weather.  Vandalism is also a problem, and occasionally people have tried to set light to the thatch.  Consequently when the wall was restored in 2017 it was decided to use a thatch which was more hard-wearing and less easy to ignite, and Dodson Bros. of Huntingdon used Norfolk sedge for the job.

Norfolk sedge, Cladium mariscus, which has the standard English name of great fen-sedge, is described by Clive Stace in his New Flora of  the British Isles, ed. 4 (2019) as ‘locally common, but very scattered’ in Britain and Ireland.  Formerly it was a valued resource in fenland areas.

Franklyn Perring et al., in their 1964 Flora of Cambridgeshire state that ‘it was considered a valuable natural crop and used for thatching of houses and barns  …  It is still abundant at Wicken Fen where the poor of the village still have the right to cut “sedge” and “litter” on the Poor’s Fen, on the third Monday in July.’

Alan Leslie in his Flora of Cambridgeshire (2019) notes that in addition to thatching Cladium was used ‘as “chaff for horse fodder”, and it “was in good demand towards winter for the tracks on the training grounds at Newmarket, and occasionally for litter’.  He also records that the nineteenth-century naturalist, Leonard Jenyns noted that Cladium ‘would be sent off in barges from Burwell Fen to Cambridge and was “the only substance used in lighting the College fires”.’

Information derived from a leaflet prepared by the Whittlesey Mud Walls Group, and from Mike Shearing, secretary of the Group, May 2017.

Photographs January 2023 © Carlos Bruzon.