He and his "comrades-in-arms", as he calls temporary housemates, get drinking water from a nearby spring, and rainwater is used for cooking and washing. "The toilet is dry composting." And for heating, he uses wood. "If there is a stove on in the room and the thermometer in the corner shows 14 degrees, we find that pleasant," says Sonnemann, who was born in Bonn and grew up in Cologne.

"Under no circumstances" is the living room heated to 20 or 21 degrees in the winter months, he says. "That would really be a waste. We also dress warmly in winter." Sonnemann gets the wood from his own plots, but also from outside. "Of course, the prices have gone up there. But I can live with that, it's not so dramatic."

All in all, Sonnemann says, people can get by with less than they think. He realises that not everyone could live in the forest like him. "We don't have that much space in Germany." But in the long run, the lifestyle enjoyed by the vast majority of the population in the developed world is not going to be sustainable, he says. "There will definitely be a change in thinking."

Sonnemann's life revolves around the rare plants he cultivates on the four-hectare site - and the seeds he harvests and sells. He has several hundred species by now, he says, spreading seeds from dried evening primrose into a bowl. "There are also plants from great-grandmother's times that would otherwise have disappeared." Like the chard variety "Hunsrücker Schnitt" or the runner beans "Hunsrücker Weiße" and "Blauhülsige".

Preserving old cultivated plants is particularly important in times of climate change because they can cope well with poor soil and extreme weather. But he also grows more exotic plants, such as courgettes from Croatia and huacatay (spice tagetes) from the Andes in South America. "That is one of my favourite plants. We regularly use it for soups and sauces, and we also make tea from it."

Helping him with his work are people who come to live with him on the farm for a period. "Right now there are eight of us. "They also come to get "a certain distance" from "the world outside", he says. "We don't live in separate world here. But all the things happening in the world right now have a comparatively small effect on us." Sometimes people even come to the farm from as far away as Mexico or Taiwan.

We talk a lot about what is happening in the world. So far, the farm has been spared from the Coronavirus pandemic. " If I've had it, it was a very mild course," says Sonnemann, whose only medical treatment in recent years has been at the dentist. "I am actually my own healer."

The residents of Longkamp in the Bernkastel-Wittlich district have respect for their neighbour in the forest. "The work he does is accepted here," says local mayor Horst Gorges (CDU). It is a worthwhile thing to preserve seeds and plants that are threatened with extinction. But only a few people in the village can understand how Sonnemann lives there.

The farm inhabitants cannot live on herbs, pumpkins, apples and quinces alone, of course. "We also buy rice or noodles," says Sonnemann, who does not see himself as a hermit or a dropout, but rather as a free spirit or bon vivant. "I don't live alone, and I didn't drop out of the world, I dropped in here. I don't do everything alone just for myself."

Original text: Birgit Reichert

Translation: Jean Lennox