Thousands of rare baby "dinosaur" trees have been placed under 24-hour security to protect them before they go on sale.
The trees have managed to survive 17 Ice Ages
About 15,000 Wollemi Pine - a tree once thought to have become extinct millions of years ago - are thriving in a greenhouse in Cornwall.
The trees, which were discovered at a secret location near Sydney in 1994, are now being grown at Kernock Park Plants nursery in Saltash.
The "crown jewels" of botany are set to feature at the Chelsea Flower show.
Horticultural expert Tony Russell, who is helping to arrange the Jurassic exhibit, said the discovery of the Wollemi Pine - a fern-like evergreen tree - was "like finding a living dinosaur".
The trees, discovered by New South Wales national parks and wildlife officer David Noble, are said to be the botanical find of the century.
"They are the crown jewels of the botanical world," Mr Russell said.
Before the discovery was made in a now secret and protected location, the only known examples of the tree were fossils dating back 175 million years.
The trees can grow up to 130ft high in the wild
To save the trees from extinction Wollemi Pine International is spearheading a project to raise saplings from the trees in the wild and make them commercially available across the world.
The money raised will help to protect the secret location from outsiders, as well as fund a research programme to establish how the tree has managed to survive 17 Ice Ages.
The owner of Kernock Plants, Richard Harnett, said in six months, at the end of the Chelsea Show, Wollemi Pines would be available for people to buy for the first time.
It is hoped that this will reduce the risk of uncontrolled exploitation.
The Wollemi Pine can grow up to 130ft (39.6m) high in the wild, with a trunk diameter of more than 3ft (91cm).