“Mary, Mary quite contrary how does your garden grow? With silver bells and cockleshells and pretty maids all in a row.” Whether the nursery rhyme was originally referring to a garden or, more likely, alluding to historical events is lost in the mists of time. Today, the song is generally illustrated in children’s books by a modest-looking girl innocently watering a herbaceous border.
If the colourful and prolific plants depicted in these images have been shipped in from the other side of the world and are being nurtured with peat and pesticides is not clear. This is, however, the case for many of Britain’s gardens.
“We like to think of gardening as a green activity, but it can have a major negative impact on our environment,” says the author and biologist Dave Goulson. “It depends on how you do it. If your idea of gardening is to drive to a garden centre to buy a trolley full of annual bedding plants in disposable plastic pots, grown in peat-based compost and drenched in pesticides, that is not so good.”
It could also be worse. “You might add a sack of peat, some fertiliser, herbicide and bug spray before heading to the checkout,” continues Goulson. You might even go the whole hog and treat yourself to some plastic grass and plastic plants.
“Gardens can be lifeless, toxic places,” he comments. “Or, with some bee-friendly flowers, no pesticides, a shaggy lawn, some wildflowers, perhaps a small pond and a bee hotel, your garden can be buzzing with biodiversity, a place where you and your children can engage with nature.”
“Shaggy” is, however, not the look many British gardeners desire. Nor do they want to be told how to make the most of their plot of land that is, according to Voltaire’s Candide, essential for happiness even if current practices are bad news for the climate, wildlife and our health.
Take peat. For 30 years or more campaigners have been banging the drum for a ban on its use in compost. The UK government is finally conducting a public consultation on restricting peat in the retail sector in England and Wales by 2024. Analysis published today (18 February) by the Wildlife Trusts shows why there should be no further delay. Peat extracted for UK horticulture in 2020 could release up to 880,000 tonnes of carbon dioxide over its lifetime, says the NGO. This is equivalent to driving an average passenger car 2.2 billion miles or pootling to the moon and back more than 4,600 times.
Since 1990 peat extraction for gardening in the UK has released up to 31 million tonnes of carbon dioxide. Waiting another two years to ban its use could add more than 1.5 million tonnes of CO2 to the atmosphere — roughly equivalent to the annual greenhouse gas emissions of more than 214,000 UK residents.
Not only is peat bad for the climate but “peatlands provide habitats for a rich diversity of plants and animals”, says Ailis Watt, peat officer at the Wildlife Trusts. “Migrating birds feed on peatland insects, while snakes and lizards thrive in these special places. The UK is already one of the most nature-depleted countries in the world and extracting peat destroys complex ecosystems that are vital for nature’s recovery.”
In some garden centres gardeners can choose peat-free alternatives, but industry progress in developing greener compost has been “slow and inconsistent”, says the Wildlife Trusts, and the much-vaunted lockdown gardening boom made things worse. From 2018 to 2019 peat consumption in the UK declined 2.3 per cent, before jumping up 9 per cent thanks to Covid-induced boredom in 2020.
“Garden centres need to take responsibility for the impacts of the products they sell,” says Goulson. “Their continuing sale of peat-based compost despite decades of campaigning about the huge climate implications of peat extraction shows they don’t give a damn.”
Regulation is necessary to change the situation, says the Wildlife Trusts, adding that “some gardeners are very wedded to the idea that peat-containing composts are of superior quality”.
This assumption seems largely redundant, given that one of the gatekeepers of the nation’s public gardens, the National Trust, hasn’t used or sold peat since 1999.
“During the second half of the twentieth century, peat became the staple ingredient in potting composts, loved for many reasons, especially its ability to absorb water,” explains Rebecca Bevan from the National Trust. “In recent years, the development of alternative peat-free growing medium has got better and better. We use mixes made of sustainably-sourced coir [coconut fibre] and composted bark. Our plant conservation centre propagates a wide range of rare and heritage plants in these peat-free mixes, even fussy plants like rhododendrons.”
The National Trust also only trades in British-grown plants, which it tries to source mainly in “hairy pots, made of biodegradable materials”. Other garden centres still have a way to go to catch up.
“This week, I visited my local garden centre, which like many others was selling magnificent tree ferns, which have become very fashionable,” says Goulson. “These ferns are taken from the wild in Tasmania, part of a legal but devastating destruction of vast areas of temperate rainforest by the logging industry. They take decades to grow. They are shipped 12,000 miles at considerable environmental cost. They will support no native wildlife, and in any case will only thrive in very mild areas and with expert care — most will die a slow death. It is a tragedy.”
How does your garden grow?