We should salute peat’s service to gardening, but we no longer need it to grow a beautiful, productive plot. Let’s bid peat adieu and gets its greener successors under our fingernails.
By John Walker. Published in Guardian Weekend, 16th June 2012.
Compost, whether it’s seed, potting or multipurpose is the fuel we run our gardens on. It’s something we all need, and always will. Compost is piled high at garden outlets right now, and the one you choose to put into your garden’s fuel tank can have profound knock-on effects for the natural world.
My own garden has been running smoothly on greener ‘fuel’ for many years – meaning I garden without peat-based compost. The interlinked problems of using mined peat – habitat destruction, loss of biodiversity, release of fossil carbon stores – have had more airplay than any other gardening activity with a direct and detrimental effect on our environment. Peat is something we should all doff our hats to: most plants thrive in it and it’s helped our horticultural industry to flourish. But we’re using peat faster than nature’s replenishing it. Gardeners use two-thirds of the peat consumed in the UK. Most of that’s imported, meaning we’re actually exporting environmental damage.
Although some plants I bring into my garden are grown in peat-based compost, more and more are raised in compost that’s 100% peat-free (some of these are available as mail order plugs). A growing number of nurseries have already switched to commercial peat-free composts. The National Trust’s gardeners haven’t used peat for many moons.
But don’t go getting the idea that it’s only the professionals or lifelong gardeners like me who can grow great plants without peat: anyone can use a reliable peat-free compost to sow, pot, propagate and grow in. Using peat-free compost isn’t the tricky bit, but choosing one that performs consistently well, from bag to bag, can be.
Last spring my greenhouse became a testing ground for almost 30 different peat-free composts, almost all of which are available to gardeners. This overkill of choice isn’t helping peat-free escape its reputation for being poor, unreliable and inconsistent. I grew plants of all types, from potatoes to primroses, in peat-frees (both cheap and pricey) sourced from DIY stores, garden centres, supermarkets and mail order suppliers.
My motivation was to see whether the ‘all peat-free is rubbish’ mantra had anything to it, or if it’s a convenient myth. Many months of note-taking and snapshots later, I can report that the talk of ‘rubbish’ is, unsurprisingly, a myth long past its sell-by date. It’s true that some peat-frees aren’t fit for gardening, but there are some planet-friendly composts that will give good, reliable results time and again.
Only a handful of peat-frees grew strong, healthy plants in my trial, and it’s easy to understand why some folk have been driven back to using peat. ‘Peat-free’ on a bag is no guarantee of success (always check that it’s suitable for sowing and/or containers, and isn’t only a planting compost/soil improver).
Most plants grow well in good quality coir-based peat-free compost. These tomato ‘Caran’, potted up as peat-free ‘plug’ plants, have produced strong roots grown in Carbon Gold All Purpose Biochar Compost.
These are my top six peat-free composts for sowing, potting and containers (prices are a guide only, to composts on sale June 2012, and exclude any delivery charge).
New Horizon Organic and Peat Free Multi-Purpose Compost Widely available, pleasant texture, and a 2012 Which? Gardening best buy container compost. Use for sowing, potting and containers. £5.99 for 50 litres.
Vital Earth Multi Purpose Compost Made from composted garden waste and bark, with long-lasting nutrients. For sowing, potting young plants, filling containers and propagation. £5.99 for 60 litres.
Carbon Gold All Purpose Biochar Compost Delightful to handle, coir-based mix containing biochar (a ‘super charcoal’ which locks up carbon), wormcasts, mycorrhizal fungi and seaweed. Certified organic. At £8.50 for a 60-litre bag this is one to spoil treasured plants with. For growing on seedlings, plugs, and for potting.
Wool Compost Made from composted bracken and wool waste, this finely textured mix is good for sowing, potting up plug plants, and filling containers. At £12.95 for 30 litres you’ll want to use it wisely.
Fertile Fibre Multipurpose Compost Organically certified, this coir mix grew healthy plants with extensive roots (although some seeds germinated poorly in it). For growing on seedlings and plug plants, and for taking cuttings. £11.95 for a 35 litre bag.
And the sixth, and greenest, of them all? Well, that’s the compost I mix myself using a 50-50 blend of garden compost and three-year-old leaf mould, both finely sieved. Although any weed seedlings are a nuisance, both seeds, seedlings and plug plants grew well, outperforming some bought peat-frees. It doesn’t cost a penny, keeps me fit (sieving reawakens unfamiliar muscles) and clocks up not a single ‘compost mile’.
If you’ve been lulled into thinking that peat-free is harder to use than peat-based, then it’s time to shed another myth: modern peat-frees will give you good results, whatever your level of gardening experience. Success with peat-free requires no more than a little familiarisation (which includes reading the instructions on the bag). If you’re unsure about watering, test the compost surface with your finger: if it’s moist underneath, don’t water. Feel the weight of the pot, too; if it feels heavy, and the plant’s not wilting, it doesn’t need watering.
Almost all seeds, large and small, can be sown in peat-free compost, especially if you choose a finer mix specifically for sowing. If you’re using a peat-free multipurpose, sieve a 1cm deep layer of finer compost and sow smaller seeds in that.
