A recent GreenBlue ArborSystem installation was carried out in an ancient courtyard at the St Catharine’s College, a constituent college of Cambridge University founded in 1473. This project was part of a refurbishment of the college which included major building works, and the alteration of the Chapel Courtyard. This college is located in central Cambridge, only about 300 metres from the centre of the world-famous punting on the River Cam.

The fully enclosed courtyard, bounded by the Chapel (which is a historic building built in 1704) and other protected buildings provides access for the students to the Library, College Dining Hall, Bar, Residences, Main Court and the Main Entrance, and so is an extremely important part of the college. It was also a site of special interest, and had to be subjected to archaeological survey before any planting could take place. This survey revealed that the site had been used by humans for living on for well over 2000 years!

The external Chapel Court works involved complete removal of the existing courtyard paving including an existing tree and replacement paving and the planting of two mature Ginkgo Biloba 40/45 cm girth trees. Due to the architectural importance of the adjacent buildings, full root protection had to be provided to ensure that no root penetration outside of the rooting zone would take place.

The decision to use the GreenBlue StrataCell system was an obvious one. The courtyard was to be hard paved and used for foot traffic – the StrataCell system would provide a well-supported and uncompacted root zone for the trees to flourish. The cost of replacing the trees if they did not do well would be prohibitive, so the Landscape Architect specified no other than the GreenBlue ArborSystem.

GreenBlue staff were on hand providing Free Tree Pit Installation Assistance throughout the project, from initial tree pit excavation inspection, right through to the completed tree planting making sure that the installation contractors were au fait with the system and happy with the installation. The trees weighed almost 3 tonnes each, and the installation of them was significantly more difficult than anticipated. Conversely, the installation of the ArborSystem Tree Pits was simplicity itself, and the whole project worked very well.

This was a demanding project, as due to the limitations on access, all plant and machinery, soil and the trees had to be craned in and out, and the chapel had to be undisturbed. Also the tree pits included live services, which had to be worked around and protected.