The mixed-use development featured a Tesco extra superstore, a 700-place car park and a rooftop student village for 900 students of Northumbria University with landscaped grounds.
Landscape architect Fairhurst and landscape contractor Bowmer and Kirkland and green roof experts City Roofs chose Green-tech’s lightweight Green-tree Intensive Roof Garden Substrate and Green-tree Amenity Tree Soil.
City Roofs commercial director Matthew Hoddinett said: "The roof garden area at Trinity Square has been an excellent project to work on and resulted in a beautiful outdoor area for the students to enjoy."
He said both the Green-tree products were of "consistent high quality".
The project has taken four years to complete with the final element unveiled last month.