Peat takes millennia to generate, and bogs store 10 times more carbon than forests — using it in gardening is madness

Mark Griffiths explains exactly why the continued practice of cutting peat from bogs for use in horticulture must be stopped.

I’ve always had a soft spot for bogs. Some of the happiest days of my childhood were spent exploring the Gower Peninsula’s mires and marshes. They gave me my first intimations of the fittedness, the supreme specialisation and intricate inter-relationships of ecosystems — their denizens the sundews and orchids were my earliest lessons in the marvels of adaptation. Their sphagnum substrate was no less of a wonder.

‘Blanket bog’ this habitat is called, although its wobble put me more in mind of the waterbed owned by a friend’s racy parents. On a visit to the Swansea Museum, I learnt that, yes, the moss was not merely a covering, but the landscape’s very body; that, down the ages, the same strands of sphagnum had grown at one end and decayed at the other to form a deep seam of peat.

We speak reverently of ‘ancient woodlands’, meaning that the trees date from 1600 or earlier, but bogs are millennia in the making. Unlike trees, they don’t proclaim their growth and age. On the surface, they appear to be time stood still. The peat beneath, however, is the chronicle of aeons.

Imagine, then, my disquiet a few years later, in the 1970s, as peat was mass-marketed by the cut-price jumbo bale as the mainstay, purported panacea and mindless addiction of almost every facet of commercial and domestic horticulture.

“A bog can store 10 times more carbon than a forest. Drain, burn or extract peat from it, however, and it will release greenhouse gases on an industrial scale”

At the time, I was blessed in having several gardening mentors who were aged between 60 and 80. They, too, looked balefully upon this boom in blanket boggery. It had never occurred to them, nor to their mentors before them, to regard peat as an all-purpose substrate. For these old Adams, the art of cultivation lay in blending the right medium (usually loam-based) for a particular plant’s needs, in which respect, they were very considerable artists indeed.

By the late 1980s, we had company. Large and growing numbers of gardeners were appalled by the idea of despoiling a pristine primeval habitat for the sake of mulching a border or stuffing a growbag. I decided that the New RHS Dictionary of Gardening should reflect this welcome shift, not least by recommending some of the better alternatives to peat that were becoming available.

Of late, Britain’s gardeners and horticultural professionals have been buying about 1.7 million cubic metres of those alternative, peat-free growing media each year. Clearly, progress has been made. Nevertheless, 2.2 million cubic metres of peat and peat-based products are sold in the UK per annum, and sales of them are beginning to increase again.

Much of this peat is sourced from Ireland (not that that makes it acceptable), but at least 18,500 acres of UK habitats are being plundered, yielding upwards of 0.8 million cubic metres a year. One Government target, that retail garden products should be peat-free by 2020, has been missed by a country mile. Another target, that commercial horticulture should stop using peat by 2030, seems overly ambitious.

The best hope lies in the link between Nature conservation and human self-preservation. Of all Earth’s terrestrial ecosystems, peatland is by far the best at sequestering CO2. A bog can store 10 times more carbon than a forest. Drain, burn or extract peat from it, however, and it will release greenhouse gases on an industrial scale. Not only do these activities make bogs dangerously mephitic, they leave them unable to perform their vital role as plant life’s great sponges — hence, as we have seen, flooding downhill from damaged peaty uplands.

“[Peat-producers’] claims were nonsense then and they’re nonsense now — unless you have a few thousand years to spare”

In 1992, I was swamped by peat-producers’ lobbyists after The New York Times reported the stand that I’d taken in the Dictionary. They said that their clients operated sustainably and responsibly; that they were reintroducing sphagnum to excavated sites so that the peat stocks would regenerate.

These claims were nonsense then and they’re nonsense now — unless you have a few thousand years to spare.

We ought to restore to their rightful quagginess bogs dehydrated by being drained, burnt or cut. But the best policy is not to damage them in the first place.

I accept that a few niche areas warrant using peat — growing carnivorous plants, for example. The amount required to meet such specialised needs is sustainably small and it could be kept that way by pricing it as the precious commodity that it is. Elsewhere, the time has come for peat to go.

It ought not to be missed. As a mulch and soil-improver, it’s inferior to well-made garden compost and leafmould. In containers, it’s rubbish — too wet, too dry, too hot in sun, too quick to sour and break down, and with no nutritive value other than the fertiliser one pumps into it.

But what about acid-loving plants? In the long term, they vastly prefer a soil-based medium — it’s not only peat that has a low pH, but all sorts of loams and clays that can be mixed with leafmould, sand, grit and garden compost to achieve the ericaceous ideal.

Finally, those new alternatives I mentioned. After 30 years of development, most are as good as peat, and some are superior, such as the outstanding products from Dalefoot Composts (www.dalefootcomposts.co.uk). Try them.

As for our 50-year dependency on peat, it has been an ignis fatuus, and I say ‘back to the bog with it’.

Mark Griffiths is a gardener, writer, historian and the editor of the ‘New RHS Dictionary of Gardening’.