Peat, Good or Bad? What You Need To Know
Wednesday, 15 April 2015 | HOTBIN Composting
Understanding peat and why the UK is seeking to ban its use in the gardening and horticulture industry.
What is Peat?
Peat usually forms in wet areas from dead organic material that is prevented from decaying due to the acidic and anaerobic conditions of the peat bog . Once removed from the "bog-like" conditions, it will quickly start to decay to a more stable humus form.
There are three main types of peat material, fibric, hemic or sapric. Most gardeners are likely to recognise two types:
- Fibrous/Fibric - Golden brown material that dries to a fluffy light material that blows in wind. This is sphagnum moss and sedge based peat, which is found in waterlogged acidic bog conditions. It is commonly used in UK composts.
- Sapric - A dark brown, almost black, sticky material that takes ages to dry out. This is very old peat that has decomposed into humic materials. It usually also has clay and minerals mixed in. This peat is more a super-rich loam soil than pure organic matter.
Why is the UK Seeking to Ban the Use of Peat?
The use of peat in the gardening and horticulture industry has significantly reduced over recent years however new targets have been published by the Department for Environment Food and Rural Affairs to eliminate the use of peat by 2020. The reasons behind this are summarised as follows:
- Loss of habitats – Many eco-systems, plants and animals alike thrive in peat bogs and once the peat has been harvested from the bog, habitats are destroyed. In simple terms, this is like chopping down a rainforest and destroying the habitats within that forest. Peat also has the ability to retain water and is responsible for expanding wetlands and the associated habitats within them.
- Unsustainable/Unrenewable - Peat is a huge carbon storage system laid down (produced) over thousands of years that take a significant amount of time to re-grow. The commercial harvesting of peat far outweighs the replacement so it could be argued that to continue harvesting is unsustainable.
More in-depth information can be found here.
Did You Know? Peat bogs are an important place for storing carbon. In one year the peat dug up for use in garden compost in Britain alone releases almost half a million tonnes of carbon dioxide – this is equivalent to 100,000 cars on the road – National Trust.
Why is Peat Proving Hard to Replace in Commerical Compost?
There are both technical performance issues and economic ones to consider
- Air Space - Peat not only retains water but also has an almost unique ability to maintain air pore space at the same time. Numerous materials absorb and retain more water than peat, but they swell and fill all the air pockets at the same time so this dual ability is key as plant roots need oxygen just as much as water.
- Sterile – Seed and plant growing mediums need to be disease and weed free. Little else grows or survives in peat bogs, peat is virtually sterile and ready to use.
- Cost – Peat is cheap to extract and peat bogs have few other ‘productive’ uses, so it is very cost effective. If however some growers use peat in plug plants to save costs then other suppliers not using peat may become 'too expensive' and be priced out of the market.
- Changing the growing media - Millions of plants are grown each spring. If the supplier gets the mix wrong it can do more harm than good with both the energy used to grow them and the plants themselves lost.
- It takes many years to properly test and modify peat reduced mixes. There is also the risk of losing a customer base if they get it wrong and another supplier sticks to the tried and tested mix of peat based plant plugs.
Note: Commissioned by DS Smith Plastics Foam Products from T Callaghan (Composter and HOTBIN inventor).