The 12,000 plants were gifted to fill the 20m bed on The Mound as part of the National Day of Reflection.
Gardeners from Edinburgh City Council brought the idea to life, helped by volunteers from nurseries and on behalf of the Scottish Horticultural Industry.
Stan Green, Director of Growforth, a plant wholesaler in Dunfermline, Fife, and Andrew Scott, Director of Reynard Nursery in Carluke, South Lanarkshire, coordinated the project.
Stan said: "Horticulture has played a vital role to play in keeping people at home and has helped to safeguard people's mental and physical wellbeing in that time.
"With nearly 90,000 people in Scotland taking up gardening last year, we know the nation has a deep connection with plants and nature and wanted to celebrate that.
"We have come together to highlight the benefits our industry can bring to a nation ready to start feeling hopeful."
BBC Scotland’s Beechgrove Garden presenter, Jim McColl said: "Spring is just around the corner and it is the perfect time to start looking forward to getting fresh air, exercise and mindfulness in your garden, if you haven't already.
"This display is a vibrant reminder to stay optimistic even as the nation reflects on the past; as we take steps towards the next phase of this pandemic situation, it's reassuring to have the certainty of the gardening year to rely on."
The plants will find new homes once the display has played its part in the National Day of Reflection with organisers distributing them to charities.
Councillor Amy McNeese-Mechan, Culture and Communities Vice Convener said: "We are delighted to have been able to support this statement of positivity as the City reflects on the last year.
"My thanks to all those who have contributed in the Scottish horticulture industry.
"This beautiful display in the centre of the city reflects the gratitude of the people of Edinburgh to those in our communities, NHS, key workers, volunteers and businesses who have gone above and beyond in this most challenging of years.
"It is also a symbol of hope to the people of Edinburgh as we look ahead to the spring."