Receiving the award, RBGE curator of living collections David Knott said:
"This is a testimony to all the hard work of the Horticulture team at RBGE.
"It is excellent for the garden, Edinburgh and Scotland that the quality of the horticultural work at the RBGE has been recognised by a fellow horticultural organisation."
The University of Edinburgh's Pollock Campus also received a Sustainable Landscaping Award from the Britain in Bloom judges. The city itself however did not feature in the main Britain in Bloom awards, announced last month.