Image caption A gin can only be called gin if it is flavoured with juniper

The future of gin is safe, according to UK horticultural experts who have been working to conserve juniper, the spirit's key ingredient.

The UK National Tree Seed Project announced it had now collected and protected seeds of juniper plants from across the country.

They will be stored in the Millennium Seed Bank in Wakehurst, Sussex.

While gin sales have enjoyed a recent boom, juniper has been threatened by disease.

A deadly fungus-like organism, Phytophthora austrocedri, has been particularly damaging for the plants in Scotland, one of the main areas for juniper growth.

Although the seed storage will not cure disease, project managers hope it will aid conservation and stop juniper falling into extinction.

The project is run by the Royal Botanic Gardens, Kew, and funded by the People's Postcode Lottery.

Project officer Simon Kallow called it "a type of insurance policy", and said the aim was to make the seed bank active and useful, so that people could use it to conduct research and conservation work.

Image copyright Desmond Dugan Image caption Juniper seed collecting at RSPB Abernethy Reserve in Scotland

Since it began in 2013, the project has "banked" 5.8 million seeds from 6,500 UK trees, and it will continue cataloguing until 2018.

Juniper is the first species to be fully collected. "We prioritise this group because it is the most threatened and also has the largest distribution, some rare, some common," said Mr Kallow. "It was completed first, largely because our partners at the Forestry Commission worked hard to collect it from many populations."

Juniper hotspots in the UK include Wiltshire, Oxfordshire, Cumbria, Conwy and the Scottish Highlands.

The juniper seeds will be kept in jars in giant freezers at -20C.

"They will be tested every now and then, by germinating them. This will happen around every 10 years," said Mr Kallow.

"Seeds can be kept alive for hundreds of years in the right conditions."

Image copyright RBG Kew Image caption Juniper berries grow across the UK, especially in Wiltshire, Oxfordshire, Cumbria, Conwy and the Scottish Highlands

UK gin sales are predicted to outstrip Scotch whisky sales by 2020, according to figures released in December.

And a spirit cannot be classed as gin unless it is flavoured with juniper.

Leon Dalloway, founder of Gin Journey, which offers gin-themed tours around the UK, welcomed the news, but said he was confident we would not be running out any time soon. "'I know at least one fairly large London distillery where they have a 'secret room' containing a year's extra stock in case there is a plight," he said.

Mr Dalloway also said most British gins also use juniper berries from overseas. "Think the Pyrenees, Tuscany, and primarily Macedonia or Bosnia. That's where the juniper harnesses the most oils. As long as their stocks are ample, we'll be all right."