Can alternatives to peat products meet both industry needs and net zero targets?

In the run up to COP26, and with increasing pressure from environmental organisations to accelerate the ban of peat products in the UK, Dr Aurélie Bovi introduces the first of a three-part series looking at the current situation. Part Two will examine available substrate alternatives and in Part Three she will consider disruptive innovations that could bring truly sustainable solutions to the horticulture sector - and help it meet ambitious net zero emissions targets.

With the UK about to host the UN global climate change summit COP26 in Glasgow later this year, and ambitious net-zero emissions targets, the pressure on accelerating the ban on the sale of all peat-containing substrates to gardeners is mounting.

Peatland restoration

In a recent report the British Ecological Society, which fully assesses the potential of nature-based solutions (NbS) to mitigate climate change and benefit biodiversity in the UK, identified the restoration of peatlands as a priority, for their ‘super’ ability to store vast amounts of carbon, reduce flood risk and support a diversity of wildlife.

Water-logged peatlands cover c.10% of the UK’s surface and store c. 3 billion tonnes of carbon – three times the amount stored in UK woodlands. But most are in a degraded state and have become a source of carbon emissions instead, accounting for 5% of UK total annual emissions.

Legislating for net zero

Announcements in mid-May from Environment Secretary, George Eustice, of a planned government consultation on banning the sale of peat and peat-containing products to amateur gardeners by 2024, has been criticised by environment organisations such as The Wildlife Trust. While they welcome the news, they also point that sales of peat products to amateur gardeners should have ended in 2020. They urge the government to bring forward that ban on sales, as well as a more complete ban on peatland burning, before COP26 or risk undermining its ambitions of leadership on climate change actions.

While the industry may have fallen short of meeting the UK Government targets set back in 2011, significant progress has been made over the past decade to offer reliable, peat-free alternatives able to match the performance of traditional peat-based products. Many professional growers are already using alternative organic materials – usually by-products of other industries, such as wood waste (bark, wood-fibre), coir and green compost, while others in the hydroponic production have settled for inorganic substitutes, such as rockwool.

How sustainable are the alternatives?

In 2020, a report from the University of Coventry, commissioned by the Horticultural Trade Association (HTA) and the UK Growing Media Association (GMA), assessed the progress towards peat removal from growing media and the drivers and barriers to further peat reduction in horticulture. It describes how considerable research and trialling has transformed the quality of alternative mixes, that can now match the performance of peat-based products.

Organic substrate alternatives, in particular, have gained popularity due to their perceived sustainable credentials. Most are plant-derived agricultural by- or co-products and therefore can appear less energy-intensive to produce; and nearly all are compostable (either onsite or offsite) or recyclable, minimising their end-of-life environmental impacts. However, most of these substitutes are imported. Their transport will impact costs and incur significant carbon footprints; and they may face challenges around availability due to competition.

In 2018, a review from AHDB, What does the future hold?, warned of the risks of competing with higher-price markets (such as heat and power generation) for limited supplies of these materials, and the difficulties it can create in securing reliable, good quality supplies at realistic prices for the Industry.

Complex problems

Recent Covid-19 impact, combined with a steady increase in demand from both amateurs and professionals alike to satisfy ‘local production’, have further confirmed these challenges. Moreover, the Coventry report also unveiled sustainability issues with these alternatives, such as high water and energy requirements, pollution, as well as social impact and resource use ‘inefficiency’, highlighting that ‘sourcing responsibly’ is not as simple as removing peat.

In Part Two of our series on the need to replace peat substrates, we examine the currently available alternatives.

For more on CHAP’s work in this area go to Growing Media. For information on CHAP’s capabilities looking at hydroponic growing  methods, go to IHCEA and Vertical Farming Development Centre.
If you are interested in working with us in the area of net zero, please send us an email using the enquiries form at the bottom of our homepage.