The £25m Calyx project, driven by the BBC's Beechgrove Gardens presenter Jim McColl, is set to become the centrepiece of an ambitious £1bn proposal by Murray Estates to create a garden district to the west of Edinburgh.
The district would feature 3,500 sustainable homes, a 25,000capacity sports arena and the Calyx project, with themed gardens, water features and educational and research facilities.
McColl said: "We have been rabbiting on for a long time about the need for a national garden. The RHS doesn't have a presence in Scotland and we are fed up of waiting. We really want something here. We are a nation of gardeners."
On previous funding bids, he said: "If you don't have lottery funding, it's a question of where are you going to get that kind of money. We kept looking and along came Murray Estates."
He added: "If the Calyx succeeds as a national garden for the people of Scotland, it will surely succeed as a massive visitor attraction."
In response to critics who argue that RBG Edinburgh is already Scotland's national garden, McColl said: "It has a different agenda and, as (Regius keeper David) Blackmore has said, he can see a relationship between it and the Calyx as similar to that between Wisley and Kew (in London)."
EDINBURGH'S GARDEN DISTRICT TIMELINE
- 1988: Calyx concept born, following garden festival.
- 1999: Project misses out on funding to Falkirk Wheel project.
- 2007: Project misses out on lottery funding for Perthshire site.
- 2010: Project wins backing as part of Edinburgh's garden district.
- 2014: Calyx development and early infrastructure due to commence.
- 2017: Calyx due to be completed and open to the public.