The Crankles

Seasonal Report on BWMG Conservation Work at The Crankles (southern part)
November 2020
The triangle of land known as The Crankles lies between the rivers Lark and Linnet, to the south of their confluence near the Abbey Gardens. Before the Reformation the Crankles lay within the Abbey precinct. The area contained a zig-zag pattern of channels said to be the remains of the monastic fish ponds, though no trace of these remains today. The area lies within Bury St
View looking south from Kevelaer Way, fruit trees in the foreground.
Edmunds Town Centre Conservation Area and is divided by the walking and cycling path, Kevelaer Way, leading to Moreton Hall estate.

From about the 1970s The Crankles contained a plantation of cricket-bat willow. These were felled in 2015 and the area re-populated with a variety of trees, planted by the then St Edmundsbury Council and BWMG volunteers . These include apple and pear, near the path through to No Man’s Meadow; alder, next to the River Lark and on the northern (Abbey) side of Kevelaer Way, and buckthorn, hawthorn and black poplar shielding the bee hives on the southern boundary. Buckthorn attracts brimstone butterflies; hawthorn has lovely blossom for nectar-seeking insects and the berries attract redwing and fieldfare in winter; black poplar is a native species particularly rare in Suffolk. All are well-suited to the damp conditions prevailing at The Crankles.

The section of The Crankles south of Kevelaer Way was, until recently, largely overgrown with nettles, thistles, dock, and cleavers. There are also other invasive plants such as hemlock. Although they are native and good for range of wildlife, there is a limit to how much an area can support. BWMG is working to reduce these species and encourage conversion to wildflower meadow in the central part of the area. This is being achieved by twice-yearly mowing (March/April and late Summer) and removal of the cut material or “arisings”, for compost. In 2020, for the first time, we are pleased to have been able to cut by hand, using traditional scythes rather than a motor-mower. Scything is less disruptive to wildlife, less polluting and more flexible in that we can mow over time rather than in one go, thus improving diversity of habitat. Parts of this southern section of The Crankles already support knapweed, oxeye daisy, red campion, speedwell, buttercups and yarrow, vetch and plantains as well as a range of grasses. Among the rarer floral species we hope to encourage are field scabious (Knautia arvensis hedge woundwort (Stachys sylvatica), hemp agrimony (Eupatorium cannibinum), black mullein (Verbascum negrum) and yellow rattle (Rhinanthus minor), all already identified in the area by our biodiversity surveying team. We also hope that careful management will encourage grass snakes, bats, butterflies, moths, slow worms and notable bird species such as blackcap, white throat, sedge and reed warblers.

Elsewhere in The Crankles (South) BWMG is working to eradicate nettle beds alongside the River Linnet on the western boundary by scythe-cutting once a month in the growing season. After a year or two a twice-yearly cut will be introduced, as in the main portion of the area. On the southern boundary, the banks of the ditch behind the bee hives are gradually being cleared of some scrub and dead or fallen trees, with a view to allowing more light onto the water which nearly always stands in this ditch. This will help the development of aquatic habitat, encouraging frogs, newts and water voles amongst other species. The wood thus cleared is either used to build habitat piles for smaller invertebrate life (“creepy crawlies”!) or, in the case of “brash” (smaller twigs and branches), piled up and left to rot down or removed for burning. Some scrubby growth (hawthorn, blackthorn, elder etc) is left to provide cover for birds.

Crankles South update, November 2021

Work in the southern half of the Crankles re-started in April this year after another long lockdown due to Covid 19 pandemic. As previously reported, we are engaged on two different mowing regimes in this area – one for a margin of about 15 metres on the north, east and west sides and one for the central “meadow” section. The margins have been mown four times this year, using traditional scythes by trained volunteers. The aim of this frequent mowing is to suppress nettles and other “rank” species such as thistle, cleaver and dock. The cut material (arisings) was removed and composted in heaps somewhere out of the way. Ideally arisings would be moved away altogether, but compromises have to be made when vehicle access is limited. Another two years of this treatment might be needed before we hope to see the results in terms of diversification of wildflower species and reduction in nettle colonisation.

The central part of Crankles South is one stage further ahead in the process of wildflower meadow creation. Here we have cut only once this year, in late August, again with scythes and also removing the arisings for compost. After mowing we sowed a mix of yellow rattle and general wildflowers. Yellow rattle is semi parasitic on grass which allows wildflowers to germinate in the suppressed grass sward. It is also a good nectar source as well. Next year we are planning an early cut in April and a late-summer cut in September or October. Crankles South is the most promising area in which BWMG volunteers work, in terms of the prospects of conversion to wildflower meadow. We hope in two- or three-years’ time to see our labours really bearing fruit or wildflowers!

Julian Case