Peat

peat
Peat is the horticultural world’s dirty secret.
Huge amounts are sold in bagged compost.  And yet we know that peat bogs are rapidly disappearing.  This means the loss of a rare and special habitat, but also the destruction of one of the earth’s greatest carbon stores.  Buying peat destroys the planet. And it simply isn’t necessary.
Why is peat so precious?  Peat comes from peat bogs, it is an accumulation of partially decayed organic matter. Because it is stored under water, it doesn’t release carbon as it decays.  Peat bogs are the largest and most efficient carbon store on earth (10 times more carbon per hectare than any other ecosystem, including forests) and they are an important defence against climate change.
  • Many peatlands have been growing undisturbed for thousands of years, so although they cover just 3% of the world’s land area, they hold nearly 30% of all the carbon stored on land.   
  • A loss of only 5% of UK peatland carbon equals the UK’s total annual greenhouse gas emissions.
  • Peat bogs are also a very particular ecosystem – wild areas which are home to a wealth of plants, birds and insects.
  • Peatlands are found in only a few parts of the world. Their cool, wet climate helps bog mosses and other plants break down very, very slowly to form a layer of peat, interspersed with plants, rocks and small waterbodies.
What other benefits do peat bogs bring?
  • Peat bogs and moorland offer a rare experience of wilderness, solitude and inspiration. They are evocative of bird song, windswept fresh air, rare mosses and clear, clean water. In the words of the Scottish Government, they “contribute to making human life both possible and worth living.” 
  • On a more practical level, the bogs are a flood defence and water clarification system, and a fine environment to raise sheep.
  • Archaeologist use peat bogs as time capsules. Pollen and other plant material, which has been held in the bog for thousands of years, tells us about climate and wildlife conditions of our ancestors. Destroying the bogs through peat extraction is like tearing up our history books.  
Are the peat bogs really disappearing?
Of the 70,000ha of lowland raised bog in the UK, estimates suggest that only 3,800-8,000ha remain in pristine or near-natural condition.  That’s just between 5% - 10% left.  And with nearly 95% degraded or gone, restoring peatland isn’t an option for our generation - or our children or grandchildren, or even their children. It takes a whole year to create just 1mm of peat.  That’s 1,000 years before the bog can start functioning again.
 
So, by 2015 the horticultural industry switched its extraction from UK bogs, to those of the Republic of Ireland and Eastern Europe.  We now import 68% of our peat.  This is a clear example of passing the buck on responsibility for climate emergency.
 
So why is peat so popular with gardeners? 
Partly because the horticultural industry has got lazy. Peat is easy to dig out and process into bags. Put it with other growing materials - such as loam and nutrients, minerals and fertilisers – and peat will provide an excellent medium for plants to thrive. Although it is not fertile itself, peat excels at holding artificial fertilisers added to the bagged compost.  These CRFs (controlled release fertilisers) have been developed by the industry to give the consumer an instantly effective growing medium. Equally important is peat’s structure, which helps with the key issue of drainage and water retention.  And it is light, so it’s easy to transport.
 
What can we use instead of peat?
You can make your own potting composts.  It’s not difficult, it saves money and it saves peat! See Peat Free Growing for different mixes for seeds, seedlings and potting on.
 
Buying peat free potting compost If you don’t have the space or materials to make your own potting compost, alternatives to peat have improved over the last 10 years, and the top brands perform excellently. However, our own experience at Garden Organic has shown huge variations in quality.  We believe that it really is worth spending a bit more to get a good product.
Remember
• Always ask for peat free
• Check the labels – reduced peat means there is still peat there, sometimes as much as 90%.
• Ignore claims of ‘not from an environmentally sensitive site’ – all peat bogs are sensitive habitats.
• ‘Organic’ doesn’t necessarily mean peat free.
 
Peat free growing composts are made out of a mixture of substances.  This means they may behave differently to peat based bags:
• Composted wood products such as bark, sawdust or paper mill waste make up the bulk of many peat free potting composts. These have good water-holding properties but the consistency and composition can be variable, depending on where it is sourced from.
• Green waste compost collected from local councils is also a common constituent supplying some nutrients, and can make up to one third of the mix. PAS100 certification aims to ensure that it is a consistent standard. Green waste compost is also commonly sold on its own as ‘soil improver’ but it is too rich to be used on its own as a potting compost or to fill raised beds.
• Coir is also commonly found in peat free composts, and provides a good mix of water holding and aeration. Its texture is good for seed sowing, but on its own it contains virtually no nutrients, and doesn’t hold onto added nutrients – unlike peat. Coir is the waste of a coconut husk; horticultural coir uses the waste from making coir ropes and matting. Although it puts to good use a waste product, the shipping distance is a cause for concern.
• Wool is used in some composts as it has good aeration and acts as a slow release nitrogen fertilizer.
• Composted bracken has good water-holding properties and is slightly acidic, so is ideal for ericaceous plants.
 
My garden centre doesn’t sell peat free compost.  What should I do?
Unfortunately, peat free can still be difficult to find, probably because it is more expensive than cheap peat based bags.  Make sure you ask the manager why s/he doesn’t stock peat free.  You can either explain how important the issue is, or hand them the leaflet “Why I want to buy peat free”.  Explain that you will no longer be a customer until he stocks peat free.  And that you will be encouraging your friends to do the same.