Killer chemicals

Have you had a good rummage in your garden shed recently? I mean a proper, spiderwebs-in the-face, sneeze-inducing rummage into its murkiest, dustiest corners? The reason I ask is that the average garden shed is filled with a multitude of things that are either broken, useless or, worst of all, poisonous.

My own is no exception. A recent examination revealed rusting loppers, the snapped head of a garden fork, two broken knapsack sprayers, and an ancient bottle of Rose Clear.

I know it’s ancient because many years have passed since I last sprayed a rose with chemicals. I also know it’s ancient because, like a host of other garden sprays, the chemical formulation this bottle contains is no longer approved for use by gardeners (it’s been reformulated as Rose Clear Ultra).

It now pains me to think of my younger self drenching a plant with a spray that was a mix of the systemic fungicides triforine and bupirimate (to treat black spot and mildew) and the insecticide pirimicarb (to kill aphids), just so that I could enjoy two weeks of blossom on a rose bush so stubbornly prone to disease that I subsequently got rid of it.

It also pains me to think that this bottle, with its now-forbidden mix of chemicals, might inadvertently and unknowingly be used by someone else or that it might be disposed of in a way that endangers not just humans but the world we inhabit.

Of course Rose Clear isn't the only garden spray to be withdrawn from sale and reformulated. The safety of many other garden chemicals once in common use has been under review. Most recently, motivated by increasing concern over the decline of bees and other pollinators, and its effect on the wider natural environment, the European Commission last year proposed the withdrawal of neonicotinoid insecticides for use by home gardeners.

Neonicotinoids are a relatively new class of systemic insecticides that have been described by critics as the new DDT (another chemical once considered safe and now known to be anything but). They are used to spray crops as well as to pre-treat seed, eventually translocating into the plant pollen and nectar – yet another good reason to buy organic seed or save your own. They can also stay in soil for up to 20 years, accumulating with each application.

And then there are other chemicals that gardeners have long used with impunity, in the mistaken belief that they pose no risk to humans or wildlife. Take Burgundy mixture or Bordeaux mixture, both copper-sulphate sprays used as a preventative fungicide on potato crops and still seen by some kitchen gardeners as an entirely safe organic alternative to Dithane (now also withdrawn). In fact, organically certified commercial growers are only allowed to use such copper-based sprays with special permission (a thing called a “derogation” that the grower must apply for) and only in very limited quantities. The reason is that copper is a heavy metal which gradually accumulates in the soil, with unpleasant consequences for earthworms and, some studies suggest, for human health.

I know that I'm just one of a large and growing band of gardeners reluctant to use any such chemicals in the garden. Jim Clarke, manager of Johnstown Garden Centre near Naas, celebrating its 40th year in business, confirms that there's been a sea-change in attitudes. "It's completely different to how it would have been 10 or 20 years ago, when gardeners would be looking for a spray to kill a particular insect or to treat a plant disease. Very few people want to do that anymore. Instead, it's about being as organic as possible."

Clarke agrees that there are almost certainly a lot of old garden chemicals hidden at the back of sheds all around the country. So what to do with them? Whatever else you do, don’t put them in the bin or pour them down the drain, which could have a catastrophic effect in terms of contaminating waterways and poisoning eco-systems. Instead, collect them carefully into a waterproof, lidded plastic box, wearing waterproof gloves.

The same goes for empty containers, which will still contain traces of the chemicals. Your nearest civic amenity site/local recycling centre will safely dispose of them for you. Some councils also offer a free hazardous waste collection.

Make sure that any garden chemicals you do keep are still approved for use by ringing a garden centre. Then keep them under lock and key, clearly labelled, and away from both animals and children.

A safe garden shed. That's my new year's resolution for 2014.

Diary Date:
Wednesday, January 8th at 8pm: Peter Whyte, landscape and garden consultant, will give a talk on Spring Work in the Garden for the South County Dublin Horticultural Society at Kill O'The Grange Parish Centre,
Kill Lane, Dublin 18. Admission €5.