The Green Seam garden tells the story of the former Betteshanger colliery in East Kent, now owned by Hadlow College parent Hadlow Group. The closure of the mine in 1989 devastated the local economy, but Hadlow Group is now regenerating the area through the £40m Betteshanger Sustainable Parks project.
The relandscaped 121ha country and business park will open in 2016, with a focus on green technology and research, along with education facilities provided by Hadlow College. A visitor centre, mining museum and the Green Seam garden will take pride of place.
Designers Bethany Williams and Stuart Charles Towner graduated from Hadlow this year. Their garden, built by RDC Landscape Design & Construction, includes a replica of a lift cage, steel structures echoing the shape of the pithead, a filtration water feature and a coalface made from resin-bonded east Kent slag.
Pioneer species used in the planting scheme include teasel, wild strawberry and orchids, which grow in damaged landscapes such as at Betteshanger. Species such as Lythrum and Eupatorium reference east Kent's downland habitats and wetlands.
Williams said she was "immensely proud" to have won best in show. She added: "I have loved every moment of being part of the great team that achieved what was a very ambitious build."