One of the key issues and challenges with the current fast fashion industry, is the dyeing. How can diverse approaches to developing local natural colour improve not only the industry’s effluent, but biodiversity, enterprises and soil health?

Groundswell is an annual regenerative agriculture festival in Hertfordshire that provides a forum for farmers, growers, or anyone interested in food production and the environment to learn about the theory and practical applications of regenerative farming systems.

This is the third in a series exploring fashion and its connection to agriculture, using the discussions from Groundswell as starting points for some thoughts.

This one considers dyes.

For background to the festival, first read part one of this article series — Fashion is agriculture: wool — and part two — Fashion is agriculture: leather.

Groundswell discussion 1 — British plant dyes: Diverse scales and approaches.

British plant dyes: Diverse scales and approaches.

Panel discussion at Groundswell 2023 with panellists from L-R: Zoe Gilbertson [moderator], Babs Behan (Botanical Inks), Sophie Holt (Pigment Plant Dyes), and William Hudson (Hodmedods).

Zoe Gilbertson, Babs Behan (Botanical Inks), William Hudson (Hodmedods) and Sophie Holt (Pigment Plant Dyes).

2022 seemed to be the year that textiles and fashion started to be included in these farming conversations, and Groundswell hosted this same discussion on plant dyes as an option for farms to consider. This panel brought together three folk — and a researcher — to highlight their projects that provide inspiration on scale, community and value added products.

Research.

Unfortunately I’d been stuck in a food queue for an hour and so missed the start of this talk (but when you’ve waited so long, food becomes more important). I had missed Zoe’s introduction (which based on the interactions with her over LinkedIn I’m sure were objective and insightful in regards to the necessity for “new” regenerative approaches to colour in fashion and textiles).

Babs had introduced her research project regarding creating dyestuffs from native and invasive species in the South West of England (microfunded by South West England Fibreshed). There isn’t much on this online, so I can’t give you much, but essentially Babs has been foraging the common native and invasive species of the South West to create dyes (to dye yarn with) and inks (for woodblock printing). So far I’ve seen hawthorn, mugwort, gorse, oak leaves, (dead) bracken and blackberry (bramble).

Training.

Sophie introduced her social enterprise; a dye plant farm in South Devon operating as part of the Baddaford Collective offering traineeships to support adults with additional needs into employment. They grow plants for dyestuffs under regenerative organic systems, while also providing horticultural therapy services. They’re a new business and are eager to understand their local impacts, especially as they’re a community interest company.

Utilising 6 x 35 metre beds on a half acre site, they are a seasonal enterprise and would like to grow in terms of offering, but not necessarily in size. They see the scale element in terms of how many folk can be trained, and would like to link with corporates to build traineeships particularly with Equality, Diversity, Inclusion teams. Additionally they would like to build a community dye kitchen so that everyone locally can bring stock together — which also means bigger commissions can be accepted.

Knowledge exchange.

Hodmedods are a well-established farm, focussing on pulses, grains, seeds and flours, in particular those that have been forgotten from British cuisines, such as the fava bean, Black Badger bean and quinoa. One of the co-founders William Hudson came to the panel to introduce his experiments in growing dye plants, specificially to provide inputs from an upcoming fashion brand Jasper — which I can’t find anything about online, so perhaps it’s just too research-oriented right now. Essentially he wants to “get the oil off our backs”, in terms of dependence and part of this involves fibre and fabric production. I took it that this project is about knowledge exchange rather than about supplying raw materials, though Hodmedods have planted 5-10 acres of madder and woad.

The “bioregion” movement came up, where farms can be a small link to a bigger chain; acting locally but supporting global shifts, with there being a second chance for a British fibre industry. William seemed very excited about the possibilities for usually “waste” plant materials like tomato and quinoa stalks. This is in a similar vein to the work of Circular Systems who have been developing tech and machinery to allow farmers on the ground to create added value with their hemp/rice stalks by producing a cellulosic fibre (rather than it being burnt on-farm). I don’t personally feel that we need to get carried away working on “innovative” solutions like what to do with tomato stalks — they make a useful pesticide, can be easily composted — and instead focus on what is actually causing issues (like the burning of straw). Plus this is about fibre not dye, but the drive for a system shift is there.

Commercialisation.

As always there needs to be a conversation regarding commercialisation. On the one hand we need to completely disrupt the system so that no one is even considering scalability and instead keeps everything hyperlocal and is in line with seasonality. But on the other hand, not everyone will want to think like this, or even believes they can afford to do so, so how can we close the gap in the meantime?

Colourfastness is a key challenge with colour from natural sources. You do need a large operation in order to create significant quantities all with pretty much the same quality. There are dye houses doing this — Green Matters Natural Dye Company is one — and yet there are variables with natural colour that cannot be fully controlled, such as climate and weather, soil quality and water pH, before you even consider the textiles or yarn you’re using. For this reason there needs to be a total re-education of what natural colour is. Designers have a rose-tinted view of how lovely it would be to have a naturally dyed collection without fully recognising the communication required between them and their customer, not least the additional time and money inputs required.

This conversation was mostly about the practice of growing plants for natural colour, rather than the infrastructure required, though an audience question did posit to William about the machinery required to process fibre and dyes on a farm-scale. Having experience with a woad trial in Suffolk, there were so many people hours involved in sowing, weeding and on the part of the farmer, tilling the ground and watering throughout the growing season. That’s before any harvest was done. It’s simply slower, and so any farmers getting involved with farm-scale fibre or dyes needs to be aware that a lot will come from knowledge exchange and trialling. And that goes for designers too; if you want natural colour, then you need to build relationships with those landworkers doing these trials to make it easier for you.

Before commercialisation there needs to be a lot of effort in iteration. Experimenting, collaborating, exchanging findings. That’s not usually how business is done i.e. patents, so all involved need to be aware that it takes a village.

Images: 1. Babs Behan’s research into native and invasive plant species for dyeing showing four samples [Credit: Instagram]; 2. Pigment Plant Dyes’ site at Baddaford Farm showing coreopsis, Hopi black sunflower and scabious [Credit: Instagram]; 3. British-grown quinoa [Credit: @hodmedods Instagram]; 4. Sowing woad seeds at a farm in Suffolk with the London Urban Textile Commons.

Susan Dye — of Nature’s Rainbow introduced below — attended the session and wrote up honest thoughts for a blog post on the three approaches based on her experience as a grower and dyer. Susan pragmatically identified challenges with each of these, and I thoroughly appreciate her insight. For instance:

Botanical Inks is for the luxury market, and so the limited woody shades would be about persuasion rather than desire perhaps. The harvesting of woody dye plants requires a lot of hand-intensive labour, despite the materials essentially being free or freely accessible and usually from prunings (so not ecologically destructive).
Pigment Plant Dyes is combining horticultural therapy with a product and so therein lies a clash. The training and wellbeing needs to come first, but when you’re creating a product then you have a specific timeline and yield to meet in order to continue the therapy side.
William is driven by excitement and experience in field-scale production and this could be what the dye industry needs to be galvanised. He has been assisted with knowledge from veteran Norfolk woad grower Ian Howard and further collaboration is going to be required.

Susan also identifies that all of these projects are embroiled within a value system. Products made from natural colour aren’t affordable for most, and so awareness needs to build (along with economies of scale) to increase accessibility and therefore bring the cost down. Plus the industry is up against lab-based pigments (still cost prohibitive though). What are we placing value on when it comes to producing natural dyestuffs? We have to think outside of the box that it’s only for colour, and more to do with the ecological benefits.

You can watch the full hour-long discussion on British Plant Dyes on Groundswell’s YouTube Channel.

Groundswell discussion 2 — Demos on growing dye plants from Nature’s Rainbow.

Demonstrations on growing dye plants.

Nature’s Rainbow established a demonstration dye plot on the Groundswell site and gathered folk throughout the festival for a few talks covering growing yellow, red and blue dye plants.

Nature’s Rainbow is led by husband and wife duo Susan DYE and Ashley WALKER. tHEY GROW DYE PLANTS FOR SEED AND DYESTUFFS, AS WELL AS RUN COURSES. Their demonstration dye plot has been going at the Cherry’s farm for a full year now (two festivals) and they ran sessions to show visitors the variety of colour from certain plants.

Images: 1. Sign at the Nature’s Rainbow Groundswell plot explaining reasons for growing dye plants; 2. Dyer’s camomile; 3. Common madder, dyer’s woodruff and Lady’s bedstraw; 4. The dye plot from low down showing Japanese indigo, common madder, dahlia, perennial coreopsis, bushy weld, bushy woad and bushy dyer’s camomile.

With these sections I’ll give you the notes that I took down regarding key dye plants for each colour, and then direct you to other resources from Nature’s Rainbow.

Yellow.

Abundant options but they're not equal in pigment concentration, colourfastness and lightfastness.
Some require lots of space, some require lots of care, some are simply weeds or can be foraged from wasteland.
The majority do require picking by hand, especially flower heads, which is time consuming. This increases the cost of the final dyestuffs and then of course the dyed textile or textile piece.

Weld ⇾ Reseda luteola (biennial). Learn more here.

No colour in the roots; it will produce a rosette in its first year and flower in the second, so wait until then to harvest for full amount of pigment (and then you can also save some for seeding).
Likes a warmer climate due to its North African heritage, but does prefer chalk and limestone soils here.
Don’t like being overcrowded and tend to be found on wasteland in the UK. They dislike roots being disturbed and seem to do better when they’ve self-seeded than propagated manually.

Goldenrod ⇾ Solidago virgaurea (perennial).

The colour deteriorates in storage so it’s difficult to dry (best to use fresh).
It’s a medicinal plant and is planted to encourage honeybees for a premium honey creation.
It’s recommended to grow only European Golden Rod Solidago virgaurea as Solidago canadensis (the Canadian variety) is invasive.

Dyer’s greenweed ⇾ Genista tinctoria (perennial). Learn more here.

Historically used with indigo to produce green shades. The new shoots contain a higher concentrate of pigment so pruning is essential.
It’s a native British shrub of the broom family (a legume, so also fixes nitrogen into the soil) and is hardy once established. Like weld it grows very bushy, so could be useful as a hedge. It also likes acidic loamy clay soils so suitable where other plants don’t grow.

Perennial coreopsis ⇾ Coreopsis lanceolata (perennial).

Though it’s perennial — so in theory requires less looking after than the annual coreopsis tinctoria — it needs caring for over winter as it doesn’t like the wet.
Once established though it flowers continuously from July to October though so you would get a good bedding flower and constant dyestuffs.

Coreopsis ⇾ Coreopsis tinctoria (annual). Learn more here.

Potentially likes drought as it stands up well to hot dry weather. Native to the prairies of North America.
Although it’s an annual, it can be grown as a biennial as Ashley explains here. I have experienced this when I left some plants over winter and they flowered again the following year. So potentially this can save you sowing time and seed/medium cost.

Dyer’s camomile ⇾ Anthemis tinctoria (perennial). Learn more here.

This is a weak perennial, usually dying in its second year. Until then it can become very sprawling and bushy (though mine took at least a year to establish).
It’s not particularly attractive for most pollinators, but is attractive and looks after itself with more growth coming as the flower heads are picked.

African marigold ⇾ Tagetes erecta (annual).

This is the one with larger bushy flower heads often seen in parks. Ashley and Susan say this has a cleaner colour than the French marigold.

French marigold ⇾ Tagetes patula (annual).

These are the ones with slightly smaller heads and often grown alongside tomatoes as companion plants.

Saw-wort ⇾ Serratula tinctoria (perennial). Learn more here.

A rare native herbaceous perennial that is difficult to propagate from seed, taking a while to germinate. It’s not a great dye plant for this slow-growing reason, and that it doesn’t yield much dye, though Nature’s Rainbow like it because it adds purple colour to the dye garden — and it’s a useful native pollinator.
It likes either dry acidic grassland or wet boggy land, so potentially a good one for unusable areas.

They also mentioned Tagetes lucida, a Mexican alternative to tarragon. Yellow is a super common natural colour being found in most plants, even if they’re not researched as a “dye plant” per se. For instance, I’ve had success with Calendula officinalis, dandelion and St. John’s Wort. So it’s almost more about what you have available, what works with your soil, what is in abundance, what can be processed effectively, and what holds a lot of pigment (especially if the plant is slow-growing).

Images from L-R clockwise: 1. Dyer’s coreopsis; 2. Dyer’s greenweed; 3. Weld; 4. African marigold; 5. Saw wort; 6. Dyer’s camomile [Credit: Nature’s Rainbow]

Red.

Difficult to source and grow. They require patience and enclosed/managed space.
Not particularly ornamental so require vision over the long-term.
Processing can take a while to come to fruition but shades are vibrant and lengthy in terms of fastness.

Common madder ⇾ Rubia tinctorum (herbaceous perennial). Learn more here.

It takes around 3 years before roots are of a big enough size for a harvest so does take time and effort to grow madder. It’s also invasive so needs to be planted somewhere with that in mind.
It is a sprawling plant, of the same family as cleavers so some don’t see it as useful in an ornamental garden. It also dies back in winter.
Dyer’s woodruff Asperula tinctoria is another option; it’s less invasive but way more slow growing.
Wild madder Rubia peregrina is an evergreen (like Indian madder below) so perhaps better suited in ornamental gardens but it actually isn’t as hardy and is still slow-growing.
Madder can be grown in containers or pots to prevent it spreading, but pots need to be protected from frosts (along with wherever you’ve planted in the ground).

Lady’s bedstraw ⇾ Galium verum (hardy perennial). Learn more here.

Much more frilly than common madder meaning it’s more acceptable as an ornamental, and “well behaved” so doesn’t spread like common madder.
Hedge bedstraw Galium album is another option.

Indian/Tibetan Madder ⇾ Rubia Cordifolia (perennial).

The chief dye compound munjistin gives a bright orange, so different to the madder red, though the plant has similarities to the rubia family. Seems more able to grow in pots as a climber.
The roots are also used in Ayurvedic medicine.

Images from L-R clockwise: 1. Madder root shown as an example at Groundswell; 2. Common madder roots after harvest [Credit: Nature’s Rainbow]; 3. Susan Dye showing examples of textile swatches dyed with madder; 4. Indian madder [Credit: Kew]; 5. Bed of Lady’s bedstraw [Credit: Nature’s Rainbow]; 6. Groundswell dye plot with Common mader, Dyer’s woodruff and Lady’s bedstraw.

Blue.

There are enough options for your climate and landscape, but you likely need to collaborate in order to efficiently and timely process your crop into a dyestuffs. There seems to be a high enough yield for space required.
Water conservation could be an issue with the changing climate, though the crop may prefer the sustained heat we now expect (and extends the growing season).
All types of plants containing indigo pigment require some management and cultivation to help them succeed, though some more than others i.e. Japanese.
The finished product is really where the revenue lies, so a lot of care and attention is required to ensure good yields and high pigment concentration before harvest.

Chinese woad ⇾ Isatis indigotica (biennial). Learn more here.

Potentially a subspecies of European Woad Isatis tinctoria but with slight differences. It seems to produce more indigo pigment per weight than European woad. Learn about European woad here. European woad is also noted as a noxious weed in the US so you can’t really grow it there.
Woad seeds lose their efficacy after the first year so ideally you need to use seeds immediately. The plant flowers in its first year, seeds in its second (biennial). European woad is more likely to produce only rosettes rather than flowers in the first year (what you would expect from a biennial).

Japanese Indigo ⇾ Persicaria tinctoria (annual). Learn more here.

4x more indigotin pigment than woad. There are a number of varities of Japanese indigo with properties such as being more or less bushy. The bushy variety is bred for farming because it can be harvested mechanically, but varieties with one long stem are better with hand harvesting.
It’s a wetland plant and needs water every 2-3 days on a field scale. It can get to 1 metre high.
Propagation other than seed can be done through layering via the stalk, or from cuttings. It can be sown later on in the season (less light and warmth), but does need watering everyday over its 14 day germination period.

True indigo ⇾ Indigofera tinctoria (perennial).

A deciduous shrub of the Fabaceae family (legume) it has historically been grown for the indigo pigment contained in the leaves, but also for many edible and medicinal uses.

Bengal indigo ⇾ Indigofera arrecta (perennial).

A tropical shrubby plant so needs to be grown in a greenhouse in the UK. Part of the Fabaceae family (legume) and so is also used to fix soil nitrogen.

Images from L-R clockwise: 1. Samples of vintage wool blankets dyed using plant-derived indigo, shown at Groundswell; 2. Woad seeds still on the plant; 3. Chinese woad [Credit: Nature’s Rainbow]; 4. Indigofera arrecta plant in a pot; 5. Susan Dye pointing out the rosettes of the European woad in the Groundswell dye plot; 6. Japanese indigo plants (broad-leafed variety) [Credit: Nature’s Rainbow]

Indigo extraction (hot) from woad.

Ashley and Susan demonstrated a hot woad extraction using leaves from the European woad plant.

1m2 of plant can yield enough dye for 1kg of yarn (in comparison, if the extraction is right, leaves from 1m2 of Japanese indigo can yield enough dye for 4kg of yarn).
Leaves are placed in a tub with boiling water poured over them just to cover. Over an hour the temperature needs to come down to around 50˚C — the lower temperature means a longer wait, but the precursor chemicals aren’t stable before this.
The leaves become soggy and indigo pigment is released from them into the water. The water has a green hue to it and is foamy.
An alkali reducing agent is added to create the required reaction between the pigment and oxygen. The vat then becomes a darker blue and less foamy. Ashley would dip a textile swatch into the tub to check the shade.
You’re then able to dye your fabric or yarn with the oxidation occuring over time. I think to fully understand this process, it needs to be experimented with!
Learn more about hot and cold woad extraction methods in these instruction videos.

Images: Top row from L-R — 1. Woad leaves in a plastic tub; 2. Boiling water is added to the woad leaves in the tub; 3. The leaves break down and water turns green and foamy as the vat cools; 4. An alkali is added and the water aerated to create the oxidation process. Bottom row from L-R: 1. The indigo vat from woad has turned a deep blue and is ready for dyeing; 2. Little jar of dark blue liquid, film still from instruction video [Credit: Nature’s Rainbow]; 3. Pile of used soggy woad leaves; 4. Examples of yarn, one skein showing blue from woad and one skein showing blue from Japanese indigo (unsure which is which!)

There you go, there’s some theoretical and practical insight into growing British dye plants. There are so many dyers, dye plots and general growers experimenting with various plants for dyes. The inclusion of this topic at Groundswell showed that there are serious thoughts to diversifying farm crops, not only for income, but also for benefits to biodiversity, soil health, cover cropping, efficient land use, and alternative therapies.

A lot needs to be done in order to build a suitable network for the wider use of plants for colour in textiles and fashion, though perhaps before that can even be established, there needs to be awareness raised — through smaller research projects and plots as shown above — on how natural colour differs to that of synthetic. Part of this systems shift is indeed consumers (alongside farmers, processors and designers). While natural dyeing is still seen as a hobby craft, perhaps this is what is required for the time being in order to inspire different ways of doing things for all involved.

Read four other articles on this topic:

Regenerative Wool at Groundswell.

A visit to Brickpits organic farm.

Regenerative Leather at Groundswell.

Regenerative Fashion book review.

An Additional article considering bast fibres will follow, along with other leads from the myriad of Groundswell discussions, particularly on soil and biodiversity - and its relation to the fashion system.

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Regenerative dyes at Groundswell.