Rewilding: Interview with Isabella Tree
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Rewilding: Interview with Isabella Tree

Acclaimed environmentalist says the answer's buried in plain sight...

To wild or not to wild, that is the question. For author Isabella Tree and her husband, Charles Burrell, the answer is clear – we should all heed nature’s desperate cry. By Charlotte Metcalf.

Rewilding: Interview with Isabella Tree

A Marmite Environmentalist

Isabella Tree

I am sitting across the table from one of Britain’s most controversial heroines. If anyone can be described as a Marmite environmentalist it’s Isabella Tree because, for all her ardent followers, she also faces vociferous opposition. Last year she wrote an article in The Guardian saying that veganism was not the answer to saving the planet, which received over 2.5m hits. Isabella was roundly trolled.

We’re drinking tea in the kitchen of Knepp Castle in West Sussex, where Isabella lives with her husband Charles Burrell and their son and daughter, currently at university. I confess a personal interest. In the Seventies, my parents rented part of the castle and I spent a glorious childhood summer there. Back then, the estate was functioning as a farm and I have photographs showing acres of golden wheat stretching down to the lake.

Today, Knepp has been reconquered by nature in one of Britain’s boldest environmental experiments, of which the softly-spoken, bookish Isabella is the reluctant figurehead, ever since her book Wilding, about the Knepp experiment, was published last May. Wilding has already been shortlisted for awards and been through over ten reprints, thrusting Isabella rather than Charlie into the limelight, though she insists her husband is the driving force behind Knepp’s wilding.

The day we meet, she’s due at Sussex University to take part in another debate on whether veganism can change the world. Undaunted by the trolls, Isabella’s answer is, in a word, ‘No’. ‘My daughter’s friends have watched those YouTube films about the dreadful conditions of industrial meat and dairy production and of course they’re angry,’ she says. ‘I don’t blame them for becoming vegans. But animal farming needn’t be evil. Vegans don’t realise that alternatives to dairy, like almond or soya milk, can be terrible for the environment. Almond trees need so much water and they’re constantly fogged with chemicals to get rid of insects, while soya is often grown on deforested areas and that involves carbon and soil loss.’

The Answer’s in the Soil

Dawn at Knepp

So what is the answer? It’s all in Wilding, a beautifully-written masterpiece of persuasion that represents a monument to Isabella’s obsession with soil.  After reading it, I am in no doubt about the serious threat our poor beleaguered planet is facing if we neglect it. Soil degradation is so drastic that, globally, we only have 60 harvests left (places like the Fens, where the peaty soils are rapidly desiccating, might have as few as 15). After that there’ll be no more topsoil and we won’t be able to grow food. ‘We’ve taken so much magnesium, calcium, potassium and all other minerals out of the land and those nutrients are not going back into the soil again but go out through our bodies into the sewage systems and into the sea,’ explains Isabella. ‘For every one carrot or tomato we ate in the Sixties, we have to eat ten today to get anything like the same trace elements and nutrients.’ The way forward is to involve animals.

‘Plants need animals as much as animals need plants,’ she continues. ‘The way cows chomp grass stimulates the roots, creating more growth underground so the blades can grow faster. The key thing is stocking levels, because you shouldn’t overgraze, but you can’t restore topsoil with vegetable compost alone – it needs bacteria, dung beetles, insects and so much more.’

The arguments are long and complicated but nothing like as tortuous as her and Charlie’s journey, which began 17 years ago when Charlie, who had inherited the family estate, realised a farm with claggy clay soil could no longer make money. ‘Charlie carried on and on trying, out of loyalty to his farm manager and workers, but even with all the subsidies he hit a wall,’ says Isabella.

The Return of Nature to Knepp

Knepp Castle

The Burrells made the momentous decision to return Knepp to nature, outraging their neighbours who were appalled by the unsightly nettles, thistles, ragwort and brambles that grew tall, vigorous and fast. Nearly 20 years on they still have plenty of detractors, but the Burrells’ experiment has also been globally applauded. Knepp has an advisory committee that reads like the Who’s Who of the international environmental movement and the ‘wilded’ land is now home to a plethora of rare species like nightingales, turtle doves, peregrine falcons, owls, purple emperor butterflies, scarce chaser dragonflies, bats, beavers and hundreds of other insects, plants and fungi – some of which had not been seen in Sussex for decades.

Wilding meant leaving dead trees where they were and Isabella would like the law changed so that animal carcasses can be left to rot down too, even if that might offend the ramblers and dog walkers using the right of way through Knepp’s land. ‘Letting carcasses rot into the ground is an important part of the nutrient cycle of microbes, bacteria and so on. People who were angry with us for giving up farming don’t realise that rewilding might be one of the solutions we desperately need – for climate change, water resources, biodiversity and the soil.’

‘The threats to our health are terrifying if we do nothing,’ insists Isabella. ‘The next big plague will come from industrial farming, where animals breed diseases and antibiotics are in constant use and the pathogens are becoming resistant to those antibiotics. If we only focused on the soil, we’d realise it’s a living, complex organism. The soil itself is full of potential antibiotics. Everything comes full circle back to the soil in the end but we’re only beginning to start thinking about it properly. Before the war, as a farmer you’d smell, taste and touch your soil – but now tractors have air-conditioned, sealed cabins, so we’ve lost touch with it. Soil has so much to teach us, yet we know so little about it. We need to connect humus with humility and start to respect it again. The good news is how quickly soil seems to restore itself, given the opportunity. At Knepp our soil is full of life again after only a generation.’

The Wilding Handbook

Isabella Tree & Charlie Burrell in front of Knepp Castle 2018 copy

When the Burrells started Wilding, Isabella described Knepp as ‘a voice in the wilderness’. Isabella and Charlie are now working on The Wilding Handbook, due for publication in 2021, and the wilderness that is Knepp has attained a metaphorical voice that is being heard loud and clear. Thousands have visited Knepp, including countless landowners.

‘Six hundred thousand people have walked through the door – people wanting to see if they can do something like this themselves,’ says Isabella. ‘We tell them rewilding doesn’t have to be forever. You could rewild for 25 years, provide habitats for wildlife, clean your water, store carbon and restore your soils – then turn the land back to sustainable agriculture. You could do rewilding in rotation, across the country, so it works hand in hand with food production. You only have to wild for 25 years and you’ll have clean water and no-dig sustainable tilth to grow food and provide habitat for all the species that complete the cycle.’

Isabella’s feet are firmly on the ground, and that’s exactly where we all need to be focusing: on the soil beneath us. Talk about saving the earth – Isabella and Charlie have been doing it for years.

Wilding is published by Picador, £9.99. For events where Isabella will be talking about her book and the project, see Catch her talk at Hay Festival (23 May. To stay in a luxury tent, shepherd’s hut or tree house in the Knepp Wildland, or to camp or attend a guided wildlife safari, visit


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