Using peat-free compost in your garden is a great way to cut your carbon footprint; there are a few things to consider to get the best results
Many peat-free growing media are now available, containing materials such as bark, wood fibre, coir (pictured), anaerobic digestate, bracken, sheep’s wool waste, and green waste compost.
All growing media have slightly different properties (whether containing peat or alternatives). We recommend gardeners read and follow the instructions on the packaging regarding which plants they are best suited to, paying close attention to the watering and feeding requirements.
Traditionally, peat has also been used for soil improvement and mulching but other materials are better suited to these tasks. Peat is never used as a soil improver or mulch in RHS Gardens.
Soil can be improved by incorporating well-rotted animal manures or composted plant remains; both materials can also be used for mulching, along with wood chips, wood shavings, bark and other materials.
RHS comparative experiments
We have undertaken a number of comparative trials at our gardens on peat and peat alternatives for the cultivation of ornamentals and vegetables.
The demonstrations have provided first-hand information on the benefits and challenges of different products, showing that most plants grown in peat alternatives are comparable to those grown in peat.
Most plants grown in peat alternatives are comparable to those grown in peat
An RHS plant trial on peat-free growing media for a specialist plant group (Sarracenia / pitcher plants) is currently being initiated, which will test various peat-free mixes, including use of dried sphagnum moss. As with all growing media, care is required around selection, watering, and feeding.
Sustainable sourcing is an important consideration in the environmental credentials of any peat-free alternative growing media. The RHS has worked with the Horticultural Trades Association, government and industry in developing the Responsible Sourcing Scheme (RSS) which aims to address this issue through an appropriate labelling system which is due for release soon.
The degree of sustainability associated with a growing medium will in future be indicated by its score on the RSS label, which will allow consumers to make an informed choice.