Juniper berries are used in game dishes and give gin its flavour.
Three project sites in Buckinghamshire have been set up to conserve the wild plant, Juniper, whose berries originally gave gin its flavour.
New conservation techniques will now be trialled at Bacombe Hill and Coombe Hill, Grangelands and Pulpit Hill, Lodge Hill and Aston Rowant.
In the past few decades Juniper populations have declined in Beds and Herts by 66% and 40% in Bucks.
It is estimated that Juniper could be extinct within 50 years.
Juniper is one of the first trees to colonise after the ice age.
Over the centuries it has been used in food and drink, including the use of its berries in game dishes and for gin.
However, over the past few decades juniper is in steady decline.
Nearly 70% in some southern counties
Bedfordshire's and Hertfordshire's two third juniper population decline and Buckinghamshire's 40% is worrying.
Although, other counties in southern England have lost up to 70% of their juniper populations.
A conservation charity for wild flowers, plants and fungi will undertake surveys in the lowlands of England in a bid to save the aging species.
Plantlife hopes that hundreds of volunteers across the three counties will get out and look for juniper bushes, to provide the latest information about the numbers, age and condition of junipers across the region.
According to the charity, losing juniper would mean more than just losing a single species, as it also supports more than 40 species of insect and fungus that can not survive without it.
They will trial new techniques to save juniper at 30 sites across southern England including Buckinghamshire, Gloucestershire, Hampshire, Oxfordshire, West Sussex and Wiltshire.
The project is supported by and part-funded by Buckinghamshire County Council.
The conservation charity said without help the remaining colonies in Buckinghamshire will die out all at the same time within the next few decades.