The flag, which was awarded to recognise the community involvement of the Friends of Corstorphine Hill group, was raised by Councillor Paul Edie.
Cllr Edie said that the transformation of a walled garden off Clermiston Road “stands out as a symbol of what is possible”.
He said: “The real challenge was not simply renovating it but keeping it up. The Friends have done this brilliantly.
“Within the next three weeks the Walled Garden on Corstorphine Hill will be a riot of colour. The walls have various species towering above them and this will be one of the most beautiful places in Scotland.”