The Pot House Hamlet Trust commissioned Horsfields Nursery to plant a 8.5x4m Union Jack and medals in bronze, silver and gold.
The flag was in place in time for the jubilee weekend using Salvia 'Blaze of Fire', Lobelia 'Crystal Palace' and Lobelia 'White Lady'.
Marigold 'Boy O' Boy Orange', Lobelia 'White Lady' and Marigold 'Boy O' Boy Yellow' were used to create the three medals colours.
Nursery owner Emma Horsfield said: "We were delighted to do something novel to support the Olympics. The planting will look amazing during the games."
Meanwhile, Kernock Park Plants is offering 3D living plant displays produced by its InstaPlant system to councils wanting to mark the games. Manager Chris Harnett said: "It's a great opportunity to create some excitement."