The Large Heath butterfly – a species that has seriously declined following destruction of peat bogs. (The plant in the background is Bilberry, Vaccinium myrtillus.)

This morning we walked to our local garden centre. It was good to stretch our legs, but the experience was rather disappointing. Like many such places, it has become more gift shop and cafe than a place to buy plants. The only Hollyhocks on sale were double-flowered and therefore useless to pollinators and the trays of mixed blowsy-flowered Primulas made me feel a little bilious. We came away empty handed (note 1).

Saddest of all were the huge piles of bags of compost by the entrance, most of which contained peat.

In the United Kingdom, the industrial scale extraction of peat has destroyed or damaged more than 95% of lowland bogs. In Ireland, the Irish Peatland Conservation Council (IPCC) estimate that 90% of its raised bogs have been lost (note 2). As the IPCC say: “Peat may be dirt cheap, but it costs the earth.”

Peat is composed of waterlogged, partially-decomposed plant material (including sphagnum moss and other acid-loving plants), which builds up in wetland habitats such as fens, bogs and moorland. The process is slow: about 1 millimetre of peat forms in a year, and deposits in the British Isles have gradually built up over 10,000 years. In contrast, average annual extraction from a peat bog removes 20cm (8 inches) of peat in a year, which represents 200 years of peat formation (note 3). It’s actually worse than that because bogs are drained before extraction takes place, to allow machinery to work on the site. This kills off large tracts of peat and its unique plant and animal community. Industrial scale peat extraction is no more sustainable than clear-felling rainforest to create palm oil plantations.

Peat bogs are wonderful places, full of interesting plants, including beauties such as Bog Asphodel and Grass of Parnassus, which I have previously written about. Insect life abounds there too, such as the Black Darter dragonfly and, pictured above, the Large Heath butterfly. More recently, we have realised that peat bogs are great carbon sinks, capturing carbon dioxide from the atmosphere. It has been estimated 5% of the carbon currently locked up in the UK’s peatlands is equivalent to the UK’s annual greenhouse gas emissions (note 4). Peat bogs also store vast amounts of water and slow its release into rivers, preventing catastrophic flooding (note 5).

Some three billion litres of peat are used every year in our gardens. We have known that harvesting peat is damaging and unsustainable for many years, but the majority of commercial composts still contain a large proportion of peat. Unless a bag of multi-purpose compost says it is peat free, it will contain peat. Some bags say that the peat doesn’t come from a SSSI (Site of Scientific Interest), but this is either because the extraction site is so degraded that it has no designation or if it comes from outside the United Kingdom, where the term SSSI isn’t used (note 6).

In December 2010 the British Government announced a plan to phase out the horticultural use of peat by gardeners by 2020. But as I write, peat extraction for gardening in the UK is still rising.

The following quote from Monty Don, which dates from March 2002, is still sadly true:

“Go to any garden centre and try and buy a non-peat based compost. It is certainly easier now than it was even five years ago, when you had more chance of scoring a bag of heroin over the counter at the local supermarket, but you still have to fight past the pallets of peat and peat-based composts to get to it.”

Alternatives to Peat

I stopped using peat in the 1980s.

For containers of shrubs and hardy perennials I use my home-made compost, which starts off as kitchen and garden waste. However, my own compost doesn’t rot at a high enough temperature to kill all weed seeds, so I use a commercial compost for the top inch or so of the pot, to stop light from triggering  germination of unwanted seedlings. (Peter Hill also suggests this in his February 2010 Guardian  article “Tips for a Peat Free Garden“.)

For raising seedlings and small plants, whether vegetables or wild flowers, I buy bags of peat-free compost.

The quality of composts can be variable, and I have learnt that some ones are better than others. Price can be an indicator, as you generally get what you pay for. I have had the occasional failure: about twenty years ago one (not cheap) brand of peat-free compost, whose formula has now changed, only gave me a crop of Common Inkcap fungi, rather than the potatoes I had hoped for.

If you’re switching to a peat-free compost, bear in mind that the compost may behave differently to a peat-based one. This is not necessarily a bad thing, but it’s best to check that plants really need watering. The surface of a coir or wood-chip based compost can dry out on the surface while the depths remain moist. Don’t rely on visual clues – poke a finger into the compost to check.

There is a lot of useful advice on peat-free composts online. One of the best articles I’ve found comes from the Telegraph just a couple days ago. There are also recommendations on the RHS and  Earth-Friendly Gardener websites. It includes some recommended brands. I’ve had success  New Horizon compost (a blend of coir, wood fibre and bark) and Fertile Fibre. The former is available in many garden centres, as well as DIY stores such as Homebase and Wickes. Buying online with home delivery makes sense if you don’t have a car, or a garden centre near where you live.

Peat is often used to lower soil pH, making it more suitable for growing lime-hating plants such as Blueberries and Rhododendrons. But peat-free ericaceous composts are available, including Ericaceous Wool Compost and Vital Earth Ericaceous Compost. I’ve had success growing Blueberries in a tub in a wool-based compost. On a larger scale, it is probably better to stop fighting nature and grow plants suited to your garden soil.

Notes

Note 1:  To be fair, they did have a smaller number of nice plants too, including some Cowslips and a couple of varieties of Lungwort.

Note 2: This loss has resulted from a combination of commercial peat extraction, turf cutting and forestry. See http://www.ipcc.ie/help-ipcc/be-a-peat-free-gardener/.

Note 3: Plantlife gives a higher figure: “Commercial extraction can remove over 500 years worth of ‘growth’ in a single year“.

Note 4: IUCN UK Peatland Programme (2011), Commission of Inquiry on Peatlands: Summary of Findings, October 2011. Quoted by Plantlife: https://www.plantlife.org.uk/uk/our-work/campaigning-change/why-we-need-to-keep-peat-in-the-ground-and-out-of-our-gardens.

Note 5: One inspiring story, reported in the Independent newspaper in January 2016, comes from Pickering in Yorkshire, which was flooded four times between 1999 and 2007. Rather than building an ugly and expensive flood wall in the town, local people, local councils, the Environment Agency, the Forestry Commission and DEFRA (the Department of the Environment, Food and Rural Affairs) worked together to slow water flow from surrounding moorland. The scheme worked well, the peat soaked up excess rainfall and the scheme cost only a tenth of building a flood wall.

Note 6: Even in Northern Ireland and the Isle of Man, the alternative term Area of Special Scientific Interest (ASSI) is used. Currently 32% of our peat comes from the UK, 60% from Ireland and 8% from Europe. (Plantlife: https://www.plantlife.org.uk/uk/our-work/campaigning-change/why-we-need-to-keep-peat-in-the-ground-and-out-of-our-gardens.)