Hidden Colours in the Landscape: Bark, Lichens & Wild Herbs

Exploring four lesser-known natural dye materials, their history, chemistry and the colours they may offer.

A Woodland Discovery in County Clare

Last weekend, we went for a walk at Lissycasey Cascades in County Clare. The path took us uphill through woodland where the trees were covered in extraordinary curtains of green moss.

Some of the strands hung almost to the ground, catching the light as it filtered through the branches. It was one of those places where you can't help but stop and look around.

Of course, being a natural dyer, I couldn't help thinking about colour.

The hanging growth looked like Old Man's Beard from a distance, but I am pretty sure that this is some kind of moss instead. The common name, Old Man's Beard, is given to several species of beard lichen, particularly those belonging to the genus Usnea. Nonetheless, this lovely discovery was a lovely reminder of how much interesting natural material exists all around us.

And it happened to coincide with the arrival of four new dyes at AppleOak: Old Man's Beard, Iceland Moss, Black Poplar Bark and St John's Wort.

Four very different materials, yet all connected through the long history of people discovering and working with colour in their surroundings.

More Than Just Dye Plants

When we talk about natural dyes, we often think first of the familiar plants: madder, weld, woad or Japanese indigo.

These are plants that we can cultivate, harvest and process specifically for their colour.

But natural dyeing has never been limited to cultivated plants.

Across different cultures and historical periods, people have worked with bark, roots, leaves, insects, lichens and other locally available materials.

Sometimes the results were brilliant and long-lasting. At other times they were softer, less predictable or dependent on particular preparation methods.

What connects these traditions is observation: learning which materials contain useful colouring substances and discovering how to release and fix them onto fibres.

Our four new dyes offer a wonderful opportunity to explore some of these less familiar sources of natural colour.

Old Man's Beard (Usnea barbata) - The Lichens Hanging from the Trees

Old Man's Beard is a name used for several species of beard lichen, recognisable by their long, branched, often grey-green growth.

They are particularly associated with humid environments and can be found growing on trees in suitable woodland habitats.

But lichens are not plants.

They are formed through a remarkable relationship between a fungus and one or more photosynthetic partners, usually green algae or cyanobacteria.

The fungus provides much of the structure, while the photosynthetic partner produces carbohydrates using light.

Together, they form an organism capable of occupying habitats that would be difficult for many plants.

A History of Colour

Beard lichens have a place in the history of natural dyeing.

Historical dye literature describes shades ranging from yellow and orange to greenish-yellow and reddish-brown from various Usnea species.

However, lichen dyeing is not one single technique.

Some lichens yield colours through relatively straightforward hot-water extraction, while others contain compounds that can be transformed through alkaline fermentation.

These different processes should not be confused, and not every lichen is suitable for producing the same colours.

The exact species, its chemistry and the extraction method all matter.

A Note on Responsible Harvesting

Lichens deserve particular consideration because many grow extremely slowly.

They also provide habitat and contribute to the ecology of woodlands and other environments.

Although lichens were historically collected for dyeing, this doesn't mean that harvesting wild populations is always appropriate today.

The British Lichen Society actively discourages unnecessary collection, particularly from vulnerable habitats.

Iceland Moss - A Lichen from Northern Landscapes

Cetraria islandica

Despite its name, Iceland Moss is another lichen rather than a true moss.

It grows in open, often northern or mountainous environments, including heaths and other habitats where conditions may be relatively harsh.

Unlike the long, hanging beard lichens, Iceland Moss has a more upright, flattened, branching structure.

It has a particularly interesting cultural history.

In Iceland and elsewhere in northern Europe, it was traditionally collected for food during times when other resources were limited. Its bitter substances could be reduced through preparation, allowing it to be incorporated into foods.

It has also been used in traditional herbal practices.

Iceland Moss as a Dye

Historical dyeing literature records Iceland Moss as a source of brown shades, including through extraction in boiling water.

These softer, earthy colours might seem modest compared with the brilliance of madder or indigo, but they are an important part of the history of natural textiles.

Browns, tans and muted shades were useful colours, especially when produced from locally available materials.

As with Old Man's Beard, we need to consider the ecological implications of collecting slow-growing lichens.

The fact that a material has traditional uses doesn't necessarily mean that harvesting it is sustainable in every location.

Black Poplar Bark - Colour from the Trees

Populus nigra

Trees offer a remarkable range of useful materials for natural dyeing.

Leaves, bark, galls and sometimes wood can contain colouring substances or tannins that interact with textile fibres.

Black Poplar is a deciduous tree native across parts of Europe and western Asia, often associated with river valleys and floodplains.

Its bark contains various phenolic compounds, including tannin-related substances.

These compounds are particularly interesting to natural dyers because of the way they interact with metals such as iron.

Bark, Tannins and Earthy Colours

Many bark dyes are associated with yellows, tans, browns and greys, although the precise shade depends on the species, material, extraction conditions and mordanting method.

Iron can interact with tannins and other plant compounds to produce darker shades.

This chemistry is familiar from iron-tannin inks and from various historical textile traditions.

One of the pleasures of bark dyeing is that it encourages us to look at trees differently.

A tree is not simply a source of leaves or timber. Its different tissues contain complex mixtures of chemicals that serve important biological purposes and can sometimes be used to produce colour.

For Black Poplar Bark specifically, we still have experimental questions to investigate, and I would rather leave the precise colour predictions open until we've had an opportunity to test our material.

A Connection to Irish Folklore

There are also records in Ireland of using poplar bark for domestic dyeing.

A particularly interesting account in the National Folklore Collection's Schools' Collection describes the use of poplar bark to produce brown dye, along with a reference to moss used for colouring stockings.

The record doesn't establish the exact species involved, but it offers a lovely glimpse into a time when dyeing knowledge was passed between people working with familiar materials in their own surroundings.

St John's Wort - A Familiar Herb with Unexpected Chemistry

Hypericum perforatum

St John's Wort is probably the most recognisable of our four new materials.

Its bright yellow flowers are a familiar sight in many European landscapes, and the plant has a long history of traditional herbal use.

It also has some fascinating chemistry.

The plant contains several groups of compounds, including flavonoids and the red-coloured substance hypericin.

Crush certain parts of the flowers and you may notice a reddish colour appearing.

But an important lesson in natural dyeing is, that the colour visible in a plant does not necessarily tell us which colours we can obtain on textile fibres.

What Colours Can We Expect?

A study published in the Journal of Natural Fibers in 2025 investigated St John's Wort as a textile dye.

Researchers worked with wool, linen and cotton, using different mordanting approaches.

The resulting colours included beige, golden beige, old gold, olive and tobacco shades.

These results demonstrate how the final colour depends not only on the plant material, but also on the fibre and mordanting process.

The red pigment hypericin is particularly interesting, but obtaining red textile colour from it is not as simple as preparing an ordinary hot-water dye bath.

Different colour compounds have different solubilities and affinities for fibres, and their behaviour changes according to the conditions in which we work.

St John's Wort is a wonderful example of why understanding colour chemistry can be just as rewarding as following a recipe.

Why Experimentation Still Matters

One thing these four materials have in common is that there is always more to investigate.

Even where historical recipes exist, there may be uncertainty about botanical identification, preparation methods, fibre types or the exact materials used.

And even modern dyeing experiments can produce different results depending on water quality, temperature, pH, concentration and mordants.

Building Our Knowledge Together

Natural dyeing has always been shaped by people sharing their observations.

A colour obtained in one dye pot may turn out differently in another. Sometimes that difference is frustrating, but it can also lead to discoveries.

We would love to encourage AppleOak customers and members of the Natural Dyers & Growers Academy to share their experiments, including the ones that don't turn out quite as expected.

What fibre did you use? Which mordant? How did you prepare your dye material? What colours appeared, and how did they change after rinsing or washing?

Every well-documented experiment helps us understand natural colour a little better.

We're also developing the Academy's resource libraries so that we can bring together historical research, technical information and practical observations in one growing collection.

Rather than presenting natural dyeing as a fixed set of recipes, we'd like to keep exploring the bigger picture.

Explore the Four New Dyes

Old Man's Beard, Iceland Moss, Black Poplar Bark and St John's Wort are now available from AppleOak FibreWorks.

Each offers a different opportunity to investigate natural colour, from the complex chemistry of lichens to the interaction of bark compounds with iron and the unexpected shades found in a familiar flowering herb.

We hope they'll inspire some interesting experiments.

And perhaps the next time you're walking through a woodland or across a meadow, you'll find yourself looking a little more closely at the colours that might be hidden there.

References & Further Reading

• British Lichen Society — The Use of Lichens for Dyeing (2024).

• Ethel M. Mairet — A Book on Vegetable Dyes (1916).

• Schmidt-Przewoźna, K. et al. — Eco-Friendly Dyeing Plants with Medicinal Properties: St John's Wort and Juniper as a Good Material for Textile Applications, Journal of Natural Fibers (2025).

• National Folklore Collection, Schools' Collection