Isabella Tree: ‘Rewilding a garden is not about closing the gate and letting it go’
Rewilding doesn’t mean abandoning — it means gardeners becoming a ‘keystone species’, creating a habitat where wildlife can thrive
I’ve lost count of the number of times people have told me that they’re rewilding their garden. But what they often mean is they’ve given up weeding, planting and mowing and they’re calling it nature restoration. We all know gardens like these, where the owners are too busy, too old or simply disinterested. Perhaps you are one of those people, relieved to have found justification, at last, in hanging up the trowel and doing sweet nothing. If you are, I’m afraid I have bad news for you.
Rewilding a garden is not about closing the gate and letting it go. As any farmer, church warden or gardener knows, if you leave a patch of land — however small — to its own devices it will scrub up, trees will seed and eventually they’ll shade out everything else.
From a rewilding point of view, this is the last thing you would want. What provides abundance and variety of wildlife is abundance and variety of plants, particularly flowering and fruiting plants — and they need light. Walk into a plantation or ancient woodland and you’ll notice the flowers and fruits — and all the insects and other creatures to which they give life — in the glades and rides, all the places where some degree of light can fall. There may be an abundance of fungi in closed canopy woodland, but there won’t be much else. Out of the 600 or so bird species in Europe, only a handful feed and breed in dense woodland.
In the wild, in most places in the world, what prevents the landscape from becoming nothing but trees is disturbance from large animals (though fire, storms and disease also play a part). In our rewilding project at Knepp in West Sussex, free-roaming herbivores keep the land semi-open, creating an incredibly rich variety of habitats. Longhorn cows mimic the actions of their extinct ancestor, the aurochs; herds of Exmoor ponies stand in for the extinct tarpan, and Tamworth pigs for the once-native wild boar. We have red, roe and fallow deer too and, of course, beavers. The radically different ways they graze and browse the vegetation, pulling down branches, debarking and even felling trees keeps the land dynamic, in perpetual motion.
Their dung restores the soil. Hooves, snouts and antlers open up patches of bare soil in the thatchy grass so wild flowers and other plants can colonise. Seeds are transported around the landscape in their gut, hooves and fur. Life surfaces in their wake. In just 20 years, these animals have turned 3,500 acres of depleted, polluted farmland into one of the richest biodiversity hotspots in the country. Bird species breeding at Knepp have risen from 22 in 2007 to 51 in 2025, including some of the UK’s rarest, such as nightingales and turtle doves; benefiting from the complex scrubland habitats shaped by the grazing animals.
In many ways what a gardener does is imitate these natural animal disturbances. When you prune your roses, you’re the nibbling teeth of a wild pony or deer. Shrubs have co-evolved with this animal attention and they respond by fighting back, becoming denser, stronger and thornier, and producing more flowers in case this is their last chance. Studies show that if you apply the saliva of a large herbivore to stems you’ve cut with your secateurs, the plant reads the animal’s enzymes and responds even more vigorously. (There’s a product opportunity for Dragons’ Den here somewhere.)
Likewise, when you’re digging out the stubborn roots of a dock or thistle, you’re the rootling snout of a wild boar; and when you’re pulling out the thuggish weeds, you’re the tugging tongue of a cow. When you apply blood and bone meal to your beds, you’re providing the effects of a rotting carcass.
Thinking like an animal when you’re gardening is immensely freeing. It allows you to behave organically, to shed obsessions with tidiness and open yourself to a new vision of beauty. As a gardener, you’re the keystone species, creating a looser habitat for living things. If you think like a cow, you’ll want a lawn that is full of nutritious wild flowers, and you’ll leave areas of longer grass providing cover for insects and small mammals.
If you have a pond, think like a beaver. Throw in some dead branches to provide food for aquatic insects and protection for small fish. Puddle around the edges like a water buffalo, creating pockets where aquatic plants can take root and toads and frogs can spawn.
As a rewilding gardener you’re also curator, selecting plants that will provide maximum opportunities for other life. These could be plants that extend the nectar and pollen season, and give structural variety, such as the late-flowering shrubby hare’s ear (Bupleurum fruticosum) and sticky moon carrot (Seseli gummiferum) from the Mediterranean, and Thunberg lespedeza from east Asia with its arching shoots of stunning rose-purple flowers in autumn. Managing for biodiversity means working just as hard as any other gardener, only your aim is not just to create a garden that you alone can enjoy, but that wildlife can enjoy too.
The UK is one of the most nature-depleted countries in the world. Numbers of native insects, birds and small mammals are in freefall, with one in six native British species at risk of extinction, according to the State of Nature 2023 report. Yet there are 20.6mn private gardens in the UK, covering an area three times larger than all our national parks. Imagine if all British gardeners could think like a wild boar, a beaver, an ant, a beetle or an earthworm! We’d be gardening, not just for ourselves but to save our native wildlife and our planet.
Isabella Tree is co-host of the Wilding Gardens conference, being held January 15-16 in Manchester; wildinggardens.co.uk
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