Moss in floristry
Moss in floristry is having a moment. It’s appearing as a floral foam replacement and carpeting the floor of floral installations around the globe. Last year, the New York Times did a feature on the phenomenon, shining the spotlight on florists who love the stuff.
I was one of those florists too, until I learned that in Australia and other parts of the world, moss and floristry have a very complicated (and unfortunately, unsustainable) relationship.
by Rita Feldmann, from Flowers Magazine, Issue 101, August 2024
For more than a decade I’ve walked my dog on an abandoned golf course in the Dandenong Ranges in Victoria. In that time, I’ve watched the fairways narrow and the previously manicured course be reclaimed by saplings from the surrounding bush. Underfoot, and in the dampest, shady places, moss has crept from the treed edges into the unkempt lawns like a padded, expanding carpet, just right for old dog paws.
When fully hydrated in the cooler months, this moss glows with life: spongy, shades of luminescent green, shimmering with moisture. In summer, it is virtually invisible as it dries and gives way to Bidgee Widgees and layers of twigs and leaf litter. Four years of good rain have kept this moss in optimum condition, enabling it to spread. The appearance of the thick, vegetative eiderdown suggests that perhaps one day, nature will ultimately conquer and tuck us all into bed after all.
Not the bedtime story we hoped for
However, just this week I discovered that the golf course moss is actually an invasive species. In the weeks before, I took photos on the golf course for this story, and later more shots near the railway track. Then again on the pathway back to home and finally, in my own garden. Zooming in and looking at all the pictures, I realised they all contained the same dominant species.
As I now know, it’s called Neat Feather-moss (Pseudoscleropodium purum) and it was first recorded in Victoria in 1946. Native to central Europe, the introduction of Neat Feather-moss is suspected to be a result of its use as a packing material in nursery stock. Now, thanks to being such an effective colonist, it is established in my home town. And what’s more concerning, it is being moved around by wholesalers, sent out with florists and then carried back home with consumers. I’ve seen it in bags and used it in arrangements before, I just didn’t realise it was invasive.
A little moss can go a long way
Dr Matt Dell from Deakin University, Melbourne, is a botanist who is an expert on the plant group known as bryophytes (mosses, liverworts and hornworts), with an interest in the impact of mosses as weeds. He explains that bryophytes are an important component of native vegetation, serving different critical functions within a healthy ecosystem. This includes providing habitat for fauna such as nesting material for birds and mammals.
He points out that taking mosses from the wild directly impacts plant community dynamics, including the way that plants interact with one another. Repeated harvesting in one location, or at commercial scale, has the potential to cause significant impacts to some ecosystems. And with some moss species listed as threatened, this can push fragile communities even further into the danger zone.
Transporting them to different locations raises further sustainability considerations.
“Some species are introduced from overseas and considered environmental weeds in certain locations,” Matt says. “Importing bryophytes for commercial use can lead to the introduction of species to ecosystems outside of their natural range.”
Neat Feather-moss typically spreads by fragmented stems and leaves, though in general, bryophytes have several strategies for dispersal. Only one small piece of Neat Feather-moss is required to establish a new mossy township. When this happens, and the invasive species takes over, the local species can struggle to compete.
The environmental impacts of mosses are not well understood because they have not been researched with the same level of interest as other weedy plants. But all invasive species can have negative impacts on agricultural industries, other species and even entire ecosystems.
Moss can be many mosses
There’s another problem, as Matt points out, which is illustrated by the image below. A small section of “moss” can contain many different species of moss, as well as other organisms, both native and introduced.
“Bryophytes also harbour other biological material including invertebrates, seeds, fungi and other material which can spread to new areas,” Matt explains, highlighting the biosecurity implications of moving bryophytes and soil to new regions. This can also include plant diseases, which can be transported with packaged moss. He says any moss material being transported across jurisdiction boundaries must follow quarantine procedures relevant to the region.
Mosses and other bryophytes are generally protected by legislation and should not be collected from public land. Laws may also extend to private land in some jurisdictions.
In some circumstances, permits are issued to collect mosses for commercial purposes. Individuals holding such permits would most likely be required to specify where they are collecting, which species and how much is being collected. Collecting any plants from a national park or other protected area is generally prohibited or may require a separate permit.
Moss the moisture magnet
It is no surprise that florists have long turned to moss. From a purely decorative perspective, moss can hide mechanics and give the arrangement a natural, earthy finish. Quite simply — weed or not — it is beautiful, living stuff.
In the early days of floral design, Sphagnum moss was a go-to natural base medium. That’s because Sphagnum has an exceptional ability to retain moisture. This makes it the perfect natural wet-pack and floral foam replacement. Like prehistoric plant Wettexes, once moistened and nestled up against cut stems, the moss passes on its dewy goodness and slows the process of dehydration. It is not as good as a vessel of water, but it is better than nothing at all, and can carry an arrangement through a funeral or wedding installation with just enough hydration to get the job done.
Sphagnum, climate change and biodiversity
Around the world, there is a global movement to stop using Sphagnum peat as a growing substrate in horticulture.
Peat is an earthy, carbon-rich deposit that is composed of layers of decomposed plants — Sphagnum species can be a dominant component of the vegetation in peatlands. The formation of peat is the first stage in the development of coal. Peat is usually formed in boggy areas, where oxygen levels are low and moisture levels are high. It can take thousands of years to build up a thick peat bog.
When peat is dug up, or the protective, living Sphagnum layer is stripped away, the delicate system is disturbed. In fact, Sphagnum peatlands change from being a carbon sink to becoming a carbon source when drained or degraded through peat harvesting.
Leaving Sphagnum beds undisturbed – both the mossy top layer and the peat underneath – is a powerful weapon in the fight against climate change and biodiversity loss, especially in Australia.
Sphagnum is also a ‘keystone species’ – it can modify the surrounding environment in a way that determines what other organisms can live there. As peats are formed, Sphagnum can change moisture regimes and acidity levels. This results in whole ecosystems being dependent on peats to exist.
The value in these plant communities from both biodiversity and climate mitigation perspectives cannot be overstated. Once it is removed from a patch of earth, Sphagnum’s unique abilities – to create peatlands, to support the many lifeforms that cannot exist without it, and to sequester vast amounts of carbon – are all lost. The damage caused by harvesting Sphagnum moss and peat is often irreparable.
Harvesting Sphagnum moss in Australia
In Australia, a tiny fraction of the land surface is composed of Sphagnum beds (only around 0.006% in the Sphagnum capital, Tasmania), especially when compared to New Zealand and Canada. Our national environmental laws define Alpine Sphagnum Bogs and Associated Fens as an endangered ecological community.
Dr Jennie Whinam from the University of Tasmania is an Australian expert on Sphagnum. According to Jennie, there is no such thing as sustainable harvesting of Sphagnum moss in this country.
Today, the only legally harvested Australian Sphagnum moss comes from wild populations in Tasmania, where a few remaining individuals hold licences to collect moss on private land. As Jennie explains, Forestry Tasmania ceased issuing licences to harvest Sphagnum in the late 1990s. And even on private land, these harvesters must follow strict guidelines, as removing the moss can cause significant damage to the local ecosystem.
There are other reasons Sphagnum harvesting in Australia is unsustainable. Most significantly, the slow growth rates. In Tasmania, growth rates are around 2cm per year, meaning the rate of regrowth is slower than removal. Peat accumulation rates are even slower at 2cm per century. To be considered ‘renewable’ a material must recover at a rate equal to or greater than its rate of removal. Currently we are losing Sphagnum bogs faster than they are growing. Climate change, and the associated increase in wildfires, is accelerating these losses.
Then there is the issue of illegal harvesting, particularly with orchid enthusiasts who prize the material as an addition to potting mix. Random unlicensed and untrained scalping of this resource can result in irreversible damage that has impacts beyond the local ecosystem.
But regardless of legalities, harvesting from the rare Sphagnum beds from the highlands of Australia is a step in the wrong direction. Quite simply, the more Sphagnum we leave on the ground, and out of floristry, the better off we all are in the long run.
Moss and “sustainable floristry”
“As long as bryophytes are being collected from the wild, this practice should not be considered sustainable in floristry”. That’s also the conclusion of Dr Matt Dell regarding the use of all species of moss in floristry.
As it stands, there are no industry standards or procedures for the collection of bryophytes for floristry use, other than the Code of Practice for licenced Sphagnum harvesters in Tasmania. According to Matt, collecting is not recorded or quantified, and there is typically no knowledge of species being traded. Also, there are no adequate quarantine procedures or evaluation of ecological impacts for which sustainability criteria can be assessed against.
Commercial farming of mosses has potential, but is only in its infancy overseas. The benefits of farmed moss are multiple: the need to remove it from the wild is removed and it’s easier to control which species are being grown and traded within the industry. This significantly reduces the quarantine and ecological risks.
So what am I supposed to use now?
For florists, all this information is, understandably, very frustrating. Especially when we’ve moved towards using moss in the belief that we are doing the right thing — that it is a more sustainable alternative to floral foam.
That’s the thing about ‘sustainable floristry’ — it is an ever-changing target, with boundaries we are only just beginning to explore. The important thing is that as these types of understandings come to light, that we act on them as an industry. If we are to build a truly ‘sustainable’ industry, we must accept that many things will change. Unfortunately, moving off moss is one of them.
Tips for moving off moss
Floral foam alternative:
- Wherever possible, arrange directly into water or create a hand-tied arrangement
- Use a manufactured floral foam base such as Sideau Agrawool or OshunPouch in funeral designs in place of moss
- Some Sphagnum harvested in New Zealand can be considered sustainable. However, transport impacts must be considered when using in Australia. Investigate provenance, use in small quantities and reuse as much as possible.
Decorative Alternatives:
- Use foliage for hiding mechanics. Small-leafed foliage such as box hedge or nandina can be buried deep in arrangements to cover base mechanics like chicken wire.
- Consider turf, foliage or pot plants on the ground instead of moss for larger installations.
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