“There is a strange power in bog water which prevents decay”
So declares a Danish almanack from 1837 referring to the discovery two years earlier of a body in a bog near Jelling in Denmark*. Bog water possesses this ‘strange power’ largely due to the unassuming moss known as Sphagnum, or peat moss, and its acidifying properties. A lack of oxygen in the waterlogged peat and low tempertures combine to confer this strange, preserving power on bog water,

Tollund Man – © Wikipedia
Simply put, Sphagnum absorbs minerals from the water, replacing them with acid (hydrogen ions), thus making the water around itself more acidic. The saturation of the moss with water prevents air from circulating and this combination of lack of oxygen, lack of minerals, and highly acid conditions slows the action of bacteria and fungi, the usual decay organisms. With the slowing of decomposition of the dead moss, peat develops under the living plants. So Sphagnum not only helps to preserve our past but also helps to grow bogs. It definitely deserves plant of the month status, and I haven’t got to its carbon storage and water storage abilities yet.
So here’s my Top 5 things to love about Sphagnum:
- It helps to grow bogs, my favourite place to be.
- It has a beautiful translucence and splendid colours.
- It’s an ‘ecosystem engineer’, and its ability to control its environment helps it to out-compete other bog plants.
- It was used in the Second World War for wound dressings due to its absorptive qualities and can also be used to mop up oil spills.
- It is involved in the process of carbon storage, and so helps in combating climate change.

Kokedera Moss Garden © Japanese Blog
The idea of loving anything about a moss might seem a little odd to some, especially those gardeners who engage in an annual battle to prevent its spread in their gardens. However some cultures encourage the growth of moss rather than constantly waging war against it. The Temple of Kokedera in Japan is famed for its moss gardens and the name literally means “Moss Temple”. The garden is a UNESCO World Heritage site, indicating the reverence accorded this plant in Japanese culture.
Girley Bog has approximately 12 of the 25 species of Sphagnum present in Ireland and the presence of S. augustinii and S. fuscum indicate that sections are actively growing or peat forming. This is good news for Girley Bog as the core Sphagnum rich area will be a priority area for conservation managers. Sadly, almost every year there are fires on the surface of this bog which damage the delicate plant layer, as seen below.
So as today is World Wetlands Day, I celebrate Sphagnum, to paraphrase Walt Whitman, and attempt my own ode to this extraordinary, humble plant.
Sphagnum moss, you are terrific,
You make your habitat acidic,
You live in places moist and aquatic,
Your colours really are fantastic.
Your spores explode to reproduce,
Your hummocks can be dense or loose,
You help preserve stuff from our past,
Your worth is truly unsurpassed.
The amazing qualities of Sphagnum, from carbon storage to flood prevention, as well as drought resistance and super-absorbancy, give us compelling reasons, in this era of changing climate, to research, understand and conserve the habitat of this remarkable bog plant.
*The Bog People, P.V. Glob
Visit these websites for more information on sphagnum, peatlands and climate change:
Peatlands and Climate change – International Peat Society
Well done Kate. You know your bog well. Really enjoyed reading about sphagnum moss – so interesting and informative! See you in Girley.