Field of Science

Non-green gardening - giving up peat

Peat is the partially decomposed remains of plants from peat bogs, primarily the Sphagnum, i.e., peat moss.  As such peat bogs are long-term repositories of carbon.  When that peat is "mined" and  removed from its low oxygen, low pH, water-logged environment, and spread around our gardens in the form of a soil additive or a potting mix or a starter pot, it finishes its decomposition rather quickly releasing all that stored carbon as carbon dioxide.  It's hard to think about giving up a common gardening practice because it's akin to coal mining and "dirty" coal, but it actually is, so we should.  And because peat bogs are drained so that the peat can be mined, a valuable wetland is destroyed, and the rather unique organisms that inhabit bogs have the habitat destroyed in the process.  Bogs like this formed very slowly, and they can regenerate, but they do so at a terribly slow rate, so peat use is like deforestation, a non-sustainable practice.  In this respect, TPP is as guilty as anyone.  In come places alternatives to peat, other bio-materials that would regularly decompose quickly anyways, are being sought, but so far TPP has seen no significant move in that direction in these parts.  The use of used newsprint and coconut fiber to make "peaty" pots is being to show up in the trade.  Fortunately the local municipality mulches and composts yard, garden, and wood waste which can be used to augment soil instead.  It's hard to get numbers on how big of a carbon footprint the use of peat generates; global warming is speeding up the decomposition of peat in nature as well.  Peat is more common in higher latitudes where the cold keeps things locked up for longer periods of time.  The peat problem is a particularly ironic one because gardeners in general like to think of themselves as the good guys, advancing the front of "green" living, and then it turns out our carbon footprint is bigger than anyone thought.  Besides peat is too valuable for other uses such as making that smoky malt used for whisky production.  The image above is the property of Kristian Peters, used under the terms of the Wikimedia Creative Commons. 


Anonymous said...

Not directly on the topic of peat use by gardeners, but this paper from 2001 has some interesting thoughts and numbers on peat:

"How sustainable is the use of peat for commercial energy
production?" by Anne Jelle Schilstra

It is available here:

Sorry about the long..long URL !

I´m trying to give up the brown stuff myself.

thanks for some great posts


The Phytophactor said...

Thanks for the terrific reference; peat for energy is most certainly unsustainable. Growth is so slow.

JaneB said...

More short-rotation coppice seems like the logical way to go for bio-energy that's closer to carbon-neutral... and most of the studies I've seen show a lot of biodiversity gains for bugs and birds, the roots are not disturbed so there are soil erosion (and soil carbon) gains, plus most of the fast-growing, weedy tree species best suited to this also do well on poor land, so reduce the manufactured chemical input needed for more conventional crops. Let's see every floodplain full of osiers again! That might even help with flood management...

Also, even if a bog regrows, the palaeoecological records it contained are gone forever - bogs need friends (lots of coir-based peat-substitutes available in bags from the garden-centre alongside the regular peat here, thankfully).