Peat-free compost choices
Peat-free composts are widely available and have improved in quality in recent years, making them an excellent choice, both for your plants and for the environment. So now is a good time to go peat-free – and here we look at how to choose suitable composts.
- Peat-free composts are readily available and much more environmentally sustainable
- Going peat-free helps to conserve precious peat bog habitats and combat climate change
- ‘Environmentally friendly’ and ‘organic’ composts aren’t necessarily peat-free
Benefits of peat-free compost
Going peat-free is great for the environment and the climate, and with so many excellent and readily available peat-free composts now on the market, your plants will be happy too.
Preserving our rare and precious peat bogs is vital, both for the unique biodiversity they support, as well as for the wider environment. They are important carbon stores and draining them for peat extraction releases carbon dioxide, contributing to climate change. They can also play a key role in soaking up excess rainfall, helping to prevent flooding.
Government had committed to banning the use of peat in retail bagged compost in 2024, and its use in professional horticulture in 2026, with some exemptions to 2030. However, so far government has failed to put in place legislation for these bans, so it remains unclear when the use of peat in horticulture will be legally prohibited.
Meanwhile, the RHS remains committed to becoming 100% peat-free across all operations, including shows, gardens and retail, by the end of 2025. We stopped selling peat-based composts in 2019, our RHS gardens are already 98% peat-free, and the whole organisation will be 100% peat-free by the end of 2025.
So now is a great time to join us and get started with peat-free growing.
Main ingredients of peat-free compost
Peat-free potting composts contain blends of various organic (plant-derived) materials – such as composted bark, coir, woodfibre and green compost – mixed with inorganic materials such as grit, sharp sand, rock wool and perlite. A mix of coarse and fine particles is needed to create a balanced compost that will hold enough water and air, which are essential for root growth.
The three most commonly used organic ingredients are:
Wood-based materials such as woodfibre, composted bark, sawdust, wood or paper waste are usually the main ingredient. Wood-based mixes can be tailored to the requirements of most plants, as they have excellent drainage properties, as well as a low pH.
Coir or coconut fibre – this is a waste product, mainly imported from Sri Lanka. It has excellent water-holding abilities and a sufficient mix of fine and coarse fibres to hold air in its pore spaces, to provide good growing conditions. However it doesn’t hold nutrients well. The environmental credentials of coir are debatable, due to the distance it has to be transported, but this is balanced out by the fact that it is a genuine waste material.
Green compost – many local authorities and private companies collect and compost green waste. The resulting compost tends to have a high nutrient content and 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’s usually no more than 30 per cent of the overall product.
Research is ongoing into a number of materials that, if locally available, may be useful ingredients in blended products, such as arable straw waste, wool waste, carpet waste, and paper and cardboard production waste.
Home-made potting compost
You can mix your own peat-free potting compost using home-made garden compost, leafmould and inorganic materials (loam and sand). This has the great benefits of being free and having no carbon footprint, but the results can be variable – it can be difficult to standardise the pH, moisture retention and available nutrients, and to ensure that the final mix is weed-free.
Experiment with your mix of ingredients – aim for a blend that holds moisture when watered, but doesn’t stay waterlogged. It can take a bit of practice to get this right, but is worth persevering with.
Selecting peat-free composts
When deciding between similar peat-free composts, look for good information on the packaging about how to use it and which plants it is suitable for. Also look for the Responsible Sourcing Scheme logo on the packaging, and check the environmental rating of that particular compost.
The packaging may also recommend the use of specific fertilisers with that 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 – compare fertilisers by checking the NPK ratio and the trace-element content quoted on the packaging.
See our video guide to peat-free composts:
Multi-purpose and seed compost – most of the major manufacturers produce peat-free multi-purpose products, including SylvaGrow and Westland New Horizon
Ericaceous compost – the choice for ericaceous (acid-loving) plants is more limited, but look for SylvaGrow Ericaceous
John Innes compost – for containers that will be home to plants for more than two or three years, use a peat-free John Innes compost such as SylvaGrow with John Innes. But note that traditional-recipe John Innes contains peat
- Carnivorous plant compost – though these bog plants are traditionally grown in peat, sustainable options have been developed in recent years, such as milled bark, other fibrous materials such as coir, or live sphagnum moss, combined with sharp sand, perlite or vermiculite. In fact, RHS research has now shown that carnivorous plants can be grown more successfully in peat-free mixes than in peat.
Peat-free buying tips
If the bag doesn’t say peat-free, then it most likely isn’t
Words such as ‘environmentally friendly’ and ‘organic’ may lead you to think a product is peat-free, but they don’t actually mean that it is
A good-quality peat-free compost is usually a little more expensive – price does tend to reflect quality
- Check the information on the bag to see if it’s recommended for particular uses or plant groups (such as seed sowing or growing bedding plants)
When buying plants, you may also wish to consider choosing plants that have been grown peat-free. Our list of peat-free nurseries is here to help you source more sustainably grown plants that have been raised 100% peat-free.
How to use peat-free composts
Also see our peat-free guides:
How to use peat-free compost: for seeds and cuttings
Where to buy peat-free plants: list of peat-free nurseries
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.