The pair were among 60 entrants selected for the show from more than 900 applicants and at this stage - unless there are late entries - the only entrants south of Ashburton.
Mr Whangapirita said he pictured a vision of a design the moment he heard the flower show was being held in Christchurch, and that initial dream was now becoming a reality.
He talked to Arne Cleland, who owns Pukerau Nursery near Gore, and the pair made plans to create a display on a Central Otago theme using schist rock from Central Otago and plants from Gore.
"Our enthusiasm grew on a daily basis as we were getting closer to the completed design.
"We sent it off to the committee and the next thing we knew we had been accepted because of our design concept."
Mr Whangapirita was not hinting what the theme might be.
However, he said the design would be based on Central Otago's early settlers, who had managed to put together a garden in an unforgiving environment using local products and local talent.
Entering in such a prestigious competition does not come cheaply and Mr Whangapirita is hoping a sponsor will come forward to help with the cost of purchasing materials and getting them to the site.
"We will have to stay in Christchurch for at least three weeks by the time we build the design, spend five days with people coming to look at it, and then dismantling the whole thing."
The Central Otago District Council had already provided some "great ideas and advice", for which Mr Whangapirita was very grateful.
The Ellerslie International Flower Show is an internationally renowned show which has been held since 1994 in Auckland.
However, the upcoming show will be staged in Christchurch from March 11-15 next year, after being bought last November by the Christchurch City Council.
It is expected to attract similar numbers to previous shows in Auckland and inject more than $14 million into the Christchurch economy annually.
There will be more than 250 exhibitors and 30 garden displays.
The five-day floral extravaganza will be held in North Hagley Park, and is expected to draw garden designers, garden lovers and media from around the world.
