DescriptionLeyland Street in Prescot connects the High Street with the pedestrianised Eccleston Street in Prescot town centre. Along this street were nine well-established London Plane trees which Knowsley Council decided should be removed, due to the increasing risk to properties and the breaking up of the footway through extensive surface root activity. Nine new Lime trees (Tilia cordata ‘Greenspire’) were designed back into the scheme.
As part of the Prescot Townscape Hertage Initiative, Mouchel, devised the scheme, funded by Heritage Lottery Fund, to repair, restore and improve the historic town centre.
One of the challenges faced by the design team was to provide sufficient soil volume for the long term establishment of the trees due to the limited available space underneath the pavement, particularly with the presence of numerous statutory services. Following consultation with GreenBlue Urban, tree pits were created, providing a large enough soil volume spanning underneath the carriageway and linking two tree pits together. Linking the pits reduced the soil requirement from 35 cubic metres to 23 cubic metres of quality uncompacted topsoil for the combined tree pit.
The GreenBlue Urban StrataCell system was installed spanning underneath the total width of the road due to its exceptional structural strength, which has been independently tested and is suitable for use underneath a carriageway. The StrataCell system is filled with good quality topsoil and provides a very healthy rooting profile underneath the paved surface.
The project was installed successfully by Dowhigh Limited, with onsite assistance from the GreenBlue Urban technical team. The trees were planted as shown in the cross section above, the system is adapted to take account of the underground stats. Aeration to the soil profile within the StrataCell profile is provided by a linked up circuit of perforated pipes with two air inlet access covers at the base of each tree.
The tree health will be monitored as part of GreenBlue Urbans on-going commitment to ensuring that trees planted in urban areas reach their full potential.