Vianney Clavreul, from Abbeville in the Somme, plans to walk the length of France from nearby Amiens to Sète, near Montpellier, sleeping rough and eating only wayside plants.
All the sustenance the body needs is freely available in the wild, he says.
This follows a similar expedition in 2017-18, when he walked to the south of Portugal, pulling his belongings behind him in a handcart.
Mr Clavreul is inspired by the migrations of prehistoric humans who are thought to have first left Africa two million years ago, dispersing all over Europe, Asia, and as far as Australia.
“Ever since I was a child, I have been fascinated by the question ‘how did people do it?’,” he said. “I enrolled on a course to become a nature guide, someone who knows all about the flora and fauna in our natural environment.”
After qualifying, he began experimenting to find out which wild plants were edible. “My first experiment, in the autumn of 2015, was to spend a fortnight eating only wild plants. Healthwise, I felt even better than before.”
On his last trek, he says he had plenty of interest from people he met along the way and some invited him to stop with them for the night.
“I ate 15 varieties of plants, including lots of nettles and dandelions, which grow everywhere, and seafoods,” he said. “From August to February, I also ate a lot of fruit – blackberries, apples, pears, peaches, apricots, grapes, walnuts, hazelnuts.
“Moving south in Spain, there were figs and citrus fruits. I tried fresh-water fishing but didn’t catch much.”
He did, however, buy some free-range eggs from farms so as not to run too low on protein in his diet.
For his next “migration”, from this month to around October, Mr Clavreul will be part of a group.
“Three or four of us will set off from Amiens following the rivers and canals to Sète by foot. We plan to eat only what we can gather or fish on the way, and sleep outdoors.
The journey will take two to three months and we plan to take some Shetland ponies with us to carry our belongings.”
He has set up a blog to follow their progress (initiationalaviesauvage.com) and plans 15 stops, where people can join the group for an evening.
“If anyone has a patch of land, we’d be happy to stop with them for a few days to rest the ponies,” he said. “The route will take us via Lyon, down the Rhône Valley to the Camargue and then along the coast to Sète, where we will join the Canal du Midi.”
He says free food grows all over and he would like to teach people to recognise a few edible plants and how to eat them, reducing dependency on modern agriculture, which he says is damaging the environment. “I want to make eating wild plants just part of life,” he said.
If you want to meet up with the group, email email@example.com .