More than 20% of Scotland is covered by peat, and much of our drinking water filters through these peatland catchments making them crucial for clear drinking water.
In recent years, the need to conserve this diminishing natural resource has been recognised, as peat bogs are a hugely important carbon sink. The practice of digging them up to make garden compost contributes to climate change as carbon is lost directly from the removal of surface vegetation and subsequently, over time, from within the extracted peat itself as it decomposes.
The Scottish Government has a commitment to restore Scotland’s peatlands and an element of this is to phase out the use of peat in horticulture.
Compost manufacturers have responded by producing an ever-increasing range of peat-free growing media. Over the years, the quality of these products has greatly improved, so they are definitely worth trying, even if you have tried using peat-free in the past and found some products were not great. There are now viable alternatives to use in the garden without using up the precious peat resources we have left.
A variety of alternatives to peat-based are available, including wood fibre, composted bark, pine bark, coir, and composted, green waste.
Materials Used in Peat-free Compost
Peat-free brands often recommend specific fertilisers for use with their compost: this is not a marketing ploy, as different formulations have different balances of nutrients. Use either the recommended product or one with a similar nutrient balance.
Most peat-free composts contain wood-based materials as their primary ingredient, e.g. wood fibre, composted bark, sawdust, wood, or paper waste. Wood-based mixes can be tailored to the requirements of most plants as they have excellent drainage properties as well as a low pH.
Coconut fibre or ‘coir’ is mainly imported from Sri Lanka. Coir is a waste product. It has excellent, natural water-holding abilities and a sufficient mix of fine and coarse fibres to hold air in its pore spaces, making it a good growing medium. It does not however, hold nutrients well. The environmental credentials of coir-based products are questioned due to the distance of transportation, but this is balanced out by the fact that it is a genuine waste material.
Many local authorities as well as private companies, compost green waste. The resultant compost tends to have a high nutrient content and a high pH, making it an excellent soil improver or mulch. There is an industry standard (British Standards Institution PAS100) for green compost that enforces consistent and regulated processing in order to encourage its use in potting composts. Due to its high pH and high levels of nutrients, green compost tends to be mixed with other materials to make potting compost – it can often account for no more than 30% of the overall product but things are always changing and improving.
Locally available materials
Research is ongoing into a number of materials that, while locally available, may be useful ingredients in blended products, e.g arable straw waste, wool waste, carpet waste, and paper and cardboard production waste.
Gardeners can mix well-rotted, home-made compost, leafmould, and inorganic materials (loam and sand) to make their own peat-free growing media. It is difficult to standardise pH, moisture retention, and available nutrients, however, as the materials are all made locally, but using this type of compost has a low carbon footprint.
What to Check When Buying Peat-free Products
- Wording such as ‘environmentally friendly’ and ‘organic’ can often confuse gardeners into thinking they are buying peat-free products, but if the packaging does not say ‘peat-free’, then it most likely it is not peat-free
- A good quality peat-free growing media is usually a little more expensive. The price does tend to reflect quality.
- Check the label on the bag to see if it is recommended for particular planting purposes such as for seed sowing, growing vegetables, or as a mulch.
- Follow any advice offered on the label of peat-free products as many offer slightly different watering and feeding requirements for plants.
There are massive carbon savings that can be made by keeping peat in the ground, peatlands being one of the world’s largest natural carbon stores. Globally, peatlands are estimated to hold up to one third of the Earth’s terrestrial carbon, despite only covering about 3% of the world’s surface.
Ask your local retailers to stock and promote more peat-free choices, to increase market demand, making it easier for consumers to go peat-free.