Spring tantalised us only a week ago, and will hopefully return soon, encouraging us outdoors for a spot of a garden tidying, perhaps followed by seed sowing – and compost buying. But the vast array of compost at the garden centre can be daunting, and most contain peat, so here’s some handy guidance to help you make a more sustainable choice.
In 2013, 1.9 million cubic metres of peat were used in the UK, with around two thirds of this being used by amateur gardeners. Just under half this peat came from Ireland, 38% from the UK and the rest from Northern Europe. It is estimated that globally, peat stores twice as much carbon as forests, and the UK contains about 15% of the world’s peatlands.
Carbon is stored in peat bogs because the acidic and anaerobic conditions stop material from decomposing – think peat bog man! – but when peat is drained, the carbon is released into the atmosphere as the peat dries out.
This contributes to climate change, and is already causing more extreme weather, loss of biodiversity, poverty and conflict over resources.
Peatlands cover more than 20% of Scotland and support a unique combination of wildlife and plants, with Sphagnum moss driving the peat-formation process. Other plants include carpets of colourful mosses and cotton grasses, dotted with bog asphodel, rare sedges, cuckooflower, marsh violet, sundews, common butterwort, marsh cinquefoil and marsh willowherb – providing habitat for butterflies, dragonflies, and birds including snipe, curlews, merlins and skylarks. Peatlands often feel fairly bleak – making them atmospheric, wild, attractive, isolated places – and panoramic for film sets and tourism. They also help regulate flooding, improve water quality, and support other industries including shooting, recreation and sheep grazing. Under typical conditions, peat is replaced naturally at a rate of one millimetre a year. In contrast, harvesters may extract to a depth of six to twenty-four centimetres across the entire surface of a bog.
SEPA recommends that targets are set to reduce peat use in horticulture, and Scottish Government purchasing of peat is due to be phased out this year and in England, the Natural Environment White Paper 2011 set outs targets to phase out peat use completely by 2030.
Peat-free compost options
You may already have a favourite compost, but a well-known independent testing body compares composts for growing seeds, young plants and for container growing, although their recommended peat-free options may not be available locally.
In previous years New Horizon Organic and Peat Free Multi-purpose Compost has come out very well in these tests, but it is not included in trials this year. It is available at New Hopetoun Gardens (£5.99 per 56 litre bag) – and if you are on the New Hopetoun Gardens mailing list this spring, you will have received a voucher for one bag at half price. There are also New Horizon peat-free soil improving composts and gro-bags available at New Hopetoun Gardens.
Klondyke will soon have in stock MiracleGro Peat Free Enriched All Purpose Compost (£5.99 for 50L, or two for £10). This product is a Best Buy for young plants, but did not perform quite as well for seeds or container growing.
Verve Multipurpose Peat Free Compost from B&Q (£3.76 for 60L) is a Best Buy for seed sowing and young plants
Verve Sowing and Cutting Compost was also a Best Buy for young plants (£3.12 for 12L)
For container growing, two out of the top three composts in trials were peat-free, but both are pricey (at £16 per sack) and neither is available locally: Fertile Fibres Multipurpose Compost and Melcourt Sylvagrow.
The Linlithgow DIY shop on the High Street is unfortunately currently unable to stock peat-free composts because of the large volumes which they would have to order.
Peat-free Don’t Buys for the following purposes include Waitrose & Alan Titchmarsh Peat Free Compost (seeds and seedlings), Gro-Sure Peat Free All Purpose Compost with 4 month feed (seedlings and containers), Dalefoot Wool Compost for Seeds (seedlings and containers) and Carbon Gold Gro-Char All Purpose Compost (seedlings).
If you have the time and space, the cheapest way of getting compost is to make your own (also great if you like a bit of exercise and playing with soil…) There are loads of recipes for different compost mixes online, with the simplest being sieved leafmould for seedlings, and equal volumes of garden compost, leafmould and loam (composted turf) for potting on.
Amateur gardeners’ use of peat-based compost creates significant demand for this product – and major environmental damage.
Read the label – if it doesn’t declare that it’s peat-free, then it probably isn’t.
Choosing one bag of compost over another may not feel like a planet-changing act, but if we all put the environment before habit (or confusion), then we can make a real difference.