In the decades following the Second World War, British farmers were encouraged and even financially incentivised to remove the ancient hedgerows that had defined the countryside for centuries. It was presented as progress, as modernisation, the inevitable march towards efficient, mechanised farming. Looking back now, it stands as one of the most shortsighted agricultural policies of the twentieth century.

Between 1945 and 1990, Britain lost nearly half its hedgerows. Miles upon miles of hawthorn, blackthorn, and field maple were torn out to create larger fields suitable for the new machinery arriving from America. The government subsidised this destruction through grants that paid farmers to remove what were suddenly seen as obstacles rather than assets. The logic seemed simple at the time: bigger fields meant more efficient ploughing, harvesting, and spraying. Hedgerows were old-fashioned, belonged to the horse and cart era, and had no place in the modern agricultural landscape.

What we failed to recognise or chose to ignore was that hedgerows were never just boundary markers. They were intricate ecosystems, wildlife corridors, natural flood defences, and windbreaks all at once. A mature hedgerow might be home to over 2,000 species of insects, 65 species of birds, and 20 species of mammals. These weren’t decorative features; they were working parts of a functioning agricultural system that had evolved over centuries.

The ecological consequences became apparent within a generation. Bird populations crashed as nesting sites disappeared. Species like the yellowhammer, linnet, and bullfinch, once common farmland birds, saw their numbers plummet. Beneficial insects that preyed on crop pests vanished along with their hedgerow homes, leading to increased dependence on chemical pesticides. The very pollinators that farmers relied upon for their fruit crops found themselves with nowhere to shelter or overwinter.

But the damage wasn’t merely ecological. Without hedgerows to slow the wind, soil erosion accelerated across the exposed flatlands. The removal of these natural barriers meant that topsoil, the foundation of agricultural productivity, was literally blowing away. During heavy rains, water that once filtered slowly through hedgerow root systems now rushed straight across bare fields, carrying soil and agricultural chemicals into waterways and contributing to downstream flooding. Farmers were effectively undermining their own future productivity for short-term gains.

The economic argument for removal proved hollow too. While larger fields did accommodate bigger machinery, the loss of natural pest control, pollination, and soil stability created hidden costs that far outweighed the efficiency gains. Studies have since demonstrated that farms with good hedgerow networks actually produce better long-term yields, precisely because they maintain the ecological services that industrial agriculture tried to replace with chemicals.

Perhaps most tragically, we destroyed something irreplaceable. Many of the hedgerows removed were hundreds of years old, some dating back to Saxon times. These weren’t just collections of shrubs but historical archives, containing plant species that indicated their age and origin, shaped by generations of laying and coppicing. A mature hedgerow represents centuries of accumulated ecological complexity that cannot be recreated by simply planting new saplings.

The policy emerged from understandable pressures. Post-war Britain needed to feed itself, reduce dependence on imports, and embrace technological advancement. The memory of wartime rationing was fresh, and agricultural productivity was seen as a matter of national security. But in our rush to industrialise farming, we threw out accumulated wisdom about how to work with the land rather than against it.

The hedgerow mistake reflects a wider human tendency to overvalue what we can measure and undervalue what we cannot. We could quantify the hours saved by larger fields and calculate the cost of maintaining hedgerows, but how do you put a price on ecosystem resilience or the cumulative wisdom embedded in traditional practices? This pattern repeats itself across domains. Healthcare systems prioritise measurable treatment outcomes while struggling to quantify the benefits of preventive care and social connection. Tech companies optimise for engagement metrics without accounting for the harder-to-measure impacts on attention spans and mental health. In each case, we make confident calculations based on what we can see and measure, dismissing the complex, benefits of older systems as mere sentiment or nostalgia. The true cost-benefit analysis can only be known in hindsight, often too late to undo the damage.

Today, we’re trying to reverse the damage. Farmers receive grants to plant and restore hedgerows. Agri-environment schemes recognise their value. We understand now that biodiversity isn’t a luxury but a necessity, that natural systems provide services worth far more than the land they occupy. But restoration is slow, expensive, and can never fully replace what was lost.

The hedgerow removal stands as a cautionary tale about the dangers of viewing agricultural land through a purely industrial lens. It reminds us that efficiency gains on paper can mask deeper losses in system resilience and longterm productivity. Most importantly, it demonstrates how easy it is to destroy in a few decades what took centuries to build, and how difficult it is to admit that our ancestors, working with hand tools and horse-drawn ploughs, might have understood something fundamental about sustainable farming that we, in our technology influenced confidence, have forgotten.