The Marvel of Moss

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29 January 2026

On 29 January 2026

Frequently found caressing tree trunks, roots and rocks in woodlands are soft, green carpets of tiny structures shaped like stars, feathers and ferns. This of course, is moss, a botanical marvel full of surprises. We think of damp, shady places as its natural habitat and indeed these are the conditions in which many mosses thrive. But it’s an astonishing plant that can survive in incredibly hostile environments, even the most hostile of all, space.

Four years ago, sporophytes (the tiny stalks that produce spores, by which moss reproduces) were attached to the outside of the International Space Station. They remained there for nine months. And on their return to earth, well over 80% of were found to still be alive and able to germinate. Think about that for a moment. It means they survived in an airless environment, with very low pressure, while being bombarded with intense radiation and unimaginable extremes of temperature. (The exterior of the ISS can fluctuate between 121 and minus 157 degrees C, according to NASA flight controller Robert Frost.)

Perhaps this tale of persistence against the odds isn’t as strange as it seems. Moss is a very, very old plant, first appearing around 450 million years ago. Anything that’s still around after that long is a consummate survivor. The species sent into space was spreading earth moss (Physcomitrium patens) but there are 15-25,000 worldwide, found in almost every sort of habitat, from the freezing Arctic to baking hot deserts, bare rocky mountainsides to lush lowlands, and cold, northern boreal woodlands to hot, tropical forests. They’re able survive where most other plants won’t grow, including surfaces heated to over 50 degrees C by geothermal activity.

So how do they do it?

Mosses are known for their ability to absorb water. Sphagnum moss, for example, soaks up huge amounts of liquid. (It also has antiseptic properties and was widely and successfully used during WW1 to dress wounds.) But their capacity for endurance is because many can also dry out completely and rehydrate, or freeze (they have their own internal antifreeze) and thaw. One of their mechanisms for survival is to become dormant and some can tolerate months of darkness.

They don’t have roots (which is why perfectly healthy clumps of moss are to be seen, unattached, on forest floors.) Instead, they have rhizoids, simple, hairlike structures that anchor the moss to its growing surface but don’t penetrate it. While some mosses absorb moisture and nutrients through these, others take them in through surface tissues. This allows them to colonise rocks and other bare surfaces.

Moss in the garden

For a long time, moss was seen as a nuisance, particularly when it had the audacity to establish itself in otherwise pristine lawns. However, awareness is growing that this delicate looking yet admirably robust plant has a place in our gardens.

Moss helps other plants in high temperatures, shading tree roots, keeping soil cool, and maintaining humidity during periods without water. Weary of weeding between paving stones? Allow moss to creep in and it will soften the edges, adding a feeling of freshness and helping to prevent weeds from taking hold. It can also be used to top the surface of pots containing damp-loving plants, helping compost to retain moisture.

During dry spells, a lawn containing moss will look green for much longer than one without. This is because moss needs less water than grass to keep it lush and healthy. On the other hand, its ability to suck up water mitigates the risk of flooding. If moss is growing in the lawn, it may well be there because the area is damp. Getting rid of the moss won’t help, in fact it will make your lawn even more squidgy. Grass often struggles in damp, shady areas so a possible solution is to give up the unequal battle and create a moss lawn instead. These not only look green and vibrant but also form a soft, spongy surface that offers a luxuriously cool massage for bare feet in hot weather. It won’t need mowing either! Moss is part of the solution, not the problem.

And a woodland garden simply doesn’t look or feel quite right without atmospheric touches of moss and lichen on rocks, trees and shrubs. It can add a gentle, aged-looking patina to garden structures too. Among the many treasures in Cornwall’s Lost Gardens of Heligan is the peacefully sleeping Mud Maid, a sculpture that seems to emerge from yet blend into the earth, in part because of its cloaking of ivy and moss. And moss gardens are highly valued in Japan. Here, mosses are the main event and are prized for the detail and intricate beauty of their form and the sense of contemplative tranquility they bring to the landscape.

Wildlife value

Cherished by long-tailed tits, chaffinches and wrens, moss is used to line nests to make a cosy home for young chicks, while the pleasantly damp environment within a patch or clump provides a home for invertebrates. This is well understood by blackbirds, who are often to be seen tossing it aside, looking for tasty morsels beneath.

On top of its many other commendable qualities, moss locks up carbon – it’s often more efficient than trees as a carbon sink – and helps to filter other tiny particles from the air. So much so that moss filters have been installed in some urban areas to improve air quality. These admirable plants are pioneers, among the first to grow in barren or disrupted areas, paving the way for others. In the aftermath of forest fires or deforestation they stabilise the soil surface and retain moisture. And after volcanic eruptions they colonise lava fields, helping to break down the rock and gradually create a nutrient-rich growing medium. What extraordinary plants they are. Let’s nurture them and give them the respect they deserve.

(Moss, like all wild plants, is protected by the Countryside and Wildlife Act and should not be gathered from the wild. It can be bought from sustainably farmed sources or perhaps gathered from a friend’s garden.)