Garden centre manager Matthew Upton said: "We are absolutely thrilled to have won Gold in the competition. There were 256 entries so to have won is a huge achievement.
"The judges were extremely impressed with our wildlife garden and conservation area, as well as all the different eco practices we carry out on-site.
"The competition was run as part of the Wild About Gardens scheme, which was organised by Canterbury City Council, Kent Wildlife Trust, the Royal Horticultural Society and other local authorities across Kent.
Millbrook Garden Centre’s wildlife garden is located next to an established native hedge, which provides a habitat for wildlife. The judges particularly liked the use of natural materials in the garden and commented on how the garden centre uses interesting ways to educate customers on wildflowers, bird and insects.
The Wild About Gardens scheme was open to all types of gardens, from balconies and courtyards to school, business and community gardens.