Recent reporting on the threat of pollution by the weedkiller clopyralid leaves gardeners without the full facts about both peat-based and peat-free composts.
By John Walker. Published on the Guardian‘s website, 27th September 2012
Twisted, buckled and puckered leaves, bulging yellow veins and contorted growth going nowhere: damage by weedkiller residue is back. It never really went away, but its comeback promises even more widespread harm, and this time it’s being egged on by journalism that might prove as harmful as the weedkiller itself.
Since 2008, when reports of something nasty lurking in animal manure first appeared, a steady flow of new incidents of pollution caused by aminopyralid have surfaced. This synthetic hormone weedkiller kills broad-leaved plants, by sending plant cells into a frenzy, but leaves grass unharmed, although it does enter it, binding to its fibres. If a cow or horse eats treated grass (fresh or as hay) the residue passes through the animal’s gut, becoming the manure we crave. If that muck arrives on an allotment site, or is sold in bags in garden centres, there’s trouble ahead.
When we mix it into our soil and it rots, minuscule polluting traces of aminopyralid are set free, and sensitive plants, including potatoes, tomatoes, peas and beans, start to pucker, buckle and twist, as their leaves and shoots go haywire. A deserved hoo-ha tightened the rules on aminopyralid’s use, which should never have gotten into muck to begin with.
“Move over aminopyralid, clopyralid, found in some garden lawn weedkillers, is the new home-grown polluter”
But aminopyralid isn’t the next chemical casting its long polluter’s shadow across our plots, although it works in the same way, causes the same deformed growth, and is equally persistent. Its carrier isn’t poisoned manure, but bags of contaminated compost and soil improver. Its origin isn’t distant sprayed fields, but our own lawns. Move over aminopyralid, clopyralid, found in some garden lawn weedkillers, is the new home-grown polluter.
The Sun newspaper’s gardening column recently ran a story headlined ‘Binfection‘, with a dramatic opener: “Disturbing reports reach us of weedkiller pollution in composts and manure.” They got the pollution bit right, but the rest looks more like a masterclass in agenda, rather than fact-driven journalism.
The Sun tells us “homeowners dump weedkiller-polluted mowings and diseased plant material in roadside bins and, where this is composted … there is a risk infected material will result”. In fact, collected garden waste is composted, professionally, to exacting standards (and to high, disease-killing temperatures). Disease outbreaks arising from bought sowing, potting and multipurpose mixes containing composted green waste are rare. And “weedkiller-polluted mowings” are exactly that: pollution, not “infection”.
More drama: “Mad cow disease resulted from feeding cattle infected food. But now we are raising plants in infected growing media rather than sterile peat or coir-based seed and potting composts.” This skips the fact that mad cow disease resulted from plant-eating cows being fed on other dead cows. It’s a terrible analogy – gardeners grow new plants using the composted remains of dead ones – but it’s OK for scaremongering.
“The Sun failed to mention by name aminopyralid or, crucially, clopyralid. It did not list lawn weedkillers containing clopyralid so readers could check”
Having been hit myself by it, I recently researched an article on weedkiller residue. Reports and pictures on the perils of aminopyralid and clopyralid pollution abound. There is no question of just how damaging these chemicals are, how they cause damage, or what it looks like.
The Sun‘s article failed to mention by name aminopyralid or, crucially, clopyralid. It did not list lawn weedkillers containing clopyralid, so readers could check if they’re using it. By neglecting to remind its readers to not put clopyralid-treated lawn mowings out for collection, it failed to help stop it entering the compost-making stream. It failed to moot the idea that we can defuse this time bomb by calling for clopyralid’s withdrawal. And it ignored a painful lesson which American gardeners learned long ago – when they were hit by clopyralid residue – which led to it being withdrawn there in 2002.
Two weeks later, another headline: ‘Weedkiller on loose: polluted compost is blight’. This second helping serves gardeners no better. It tells us: “You have now written in with a series of related cautionary tales.” Curiously, out of the six snippets taken from readers’ letters, none describe specific symptoms of weedkiller damage, but do mention other symptoms, including those of gardening in the most challenging summer ever.
Again, The Sun tells us of the perils of using products containing green waste compost, but fails to mention that it’s used not just in some peat-free compost, but in some peat-reduced products, too. It can’t resist more unfounded alarmism, suggesting that green waste compost might carry “…bacterial infections such as Legionnaire’s disease.” There is no evidence that anyone in the UK has contracted the rare Legionella longbeachae from bagged compost.
Again it fails to mention clopyralid or list the products containing it, does not urge its readers to check if it’s in their lawn weedkiller or remind them not to put treated mowings out for collection. And it fails to call, after learning others’ lessons, for an end to clopyralid use in gardens. Why?
“Peat-free composts may not be perfect, but they can be produced from renewable resources, including what goes into our garden waste bins”
The Sun‘s gardening column is a proponent of peat use, thereby encouraging the destructive mining of lowland raised peat bogs, primarily in Ireland and Europe. Peat is a non-renewable resource. The Sun rails against the reliability of peat-free composts, many of which contain the composted green waste it is making great efforts to scare us about. So it’s no surprise to find we’re being urged to use “…sterile peat or coir-based composts”.
Peat-free composts may not be perfect, but they can be produced from renewable resources, including what goes into our garden waste bins. I have trialled over 30 peat-free composts this year, some of which contain or are made from green waste. The majority have performed just as well, if not better, than composts containing mined peat.
Being a loyal champion of garden chemical use may explain why The Sun finds it hard to name the lawn weedkillers from which this entire problem springs. If the reporting of a serious problem is being tainted by an agenda, journalism is being distorted just as weedkiller residues twist plant growth. It’s a kind of insidious pollution itself, symptomised by a failure to give gardeners the facts, while milking alarmism to the full.