They hope the investigation may lead them to varieties still growing in private gardens - and provide a genetic seed bank.
The Henry Doubleday Research Association, Europe's largest organic gardening organisation, hit upon the idea when they were sent a copy of the Berrow's Worcester Journal, dated 25 February 1796.
Alongside news of Napoleon's marriage to Josephine, the Worcester seed house of James Bigg and Co announced it was stocking two radish varieties known as the salmon and the early white transparent short-topped. Bob Sherman, the association's curator, said: "This was the first time we had heard of these two particular types of radish. We also came across a reference to two varieties of potatoes which, as far as we are aware, no longer exist. We realised that, because Berrow's is so old, its archives are an incredibly valuable source of information."
He is now appealing for volunteers to hunt through 300 years of back copies of the Worcester newspaper for further references. A mention of a market gardener might identify a village where today's gardeners could be questioned about odd varieties still thriving.
Mr Sherman said: "We believe there are probably many other references in the archives which will tell us what people used to grow and eat in the 17th and 18th centuries."
The Coventry-based association has a seed library preserving more than 700 varieties of old vegetables which are not officially recognised under European regulations which demand hundreds of pounds to register them as legal for sale. Its supporters swap rare seeds to ensure they do not die out.
Mr Sherman said: "The preservation of old varieties is far beyond something you just stick in the ground, grow and eat. This is genetic material from which you can breed and it links vegetables into history."Reuse content