Category Archives: Ashley’s posts

Field Madder plant showing tiny pink four petaled flowers

Natures Rainbow Garden Update – Spring 2019

By Ashley Walker
Copyright 8th May 2019

The weather here has followed the pattern of recent springs by being dry, sunny and warm with cold intervals and frosty nights. Planting out of the Japanese indigo will have to wait for a week or two yet but most plants are thriving. Time to look at last year’s plantings and make an assessment of what has worked and what has not. Last year we embarked on growing a number of new plants, many of which are relatives of Common Madder. Of course many folks have said “What on earth are you doing that for? There is no better plant than Common Madder!” That of course is true but in the past many of these madder relatives were used as dye plants and prized for their colours so we thought we’d try and find out for ourselves how easy they are to grow and eventually what colours their roots will yield.

Wild Madder Rubia peregrina

We first started with Wild Madder (Rubia peregrina) three years ago now. Spring frosts have been particularly hard on the plants as their evergreen upper leaves are not particularly frost hardy.

Browned and crisped frost damaged evergreen leaves of Wild madder, Rubia peregrina.

Frost damaged evergreen leaves of Wild Madder.

Their native UK homelands are the southern coastline of Devon, Cornwall and Wales where they get warm sea breezes that usually prevent frosts, so here in Hertfordshire they are a bit out of their depth. However the roots are protected and soon shoot back once the warm weather returns. Getting a good harvest from the plant is going to take time, even without frosts it’s very slow growing so we’re not planning to dig any up until Autumn this year.

Shoot of Common Madder (Rubia tinctorum) showing browned shoot as a result of frost damage.

For the first time in many years our Common Madder shoots were badly frosted. Not a problem as the plants quickly produce new shoots

Even our Common Madder beds were badly affected by the frosts with many of the new shoots being crisped.

Field Madder Sherardia arvensis & Hedge Bedstraw Galium mollugo

Field Madder Sherardia arvensis A cushion of Field Madder growing under a Weld plant with Sawort to the left. This plant self seeded last year and has come through the winter without any frost or snow damage.

A cushion of Field Madder growing under a Weld plant with Sawort to the left. This plant self seeded last year and has come through the winter without any frost or snow damage.

Generally described as an annual weed, we discovered that given plenty of attention this plant is perfectly capable of going through the winter and withstanding any frosts. Does this make it a short lived perennial? Many hardy annuals can do this and provided they are watered and fed can keep on growing. As this plant has very thin roots, getting a harvest is obviously going to be a bit of a test so we’ve decided to do a little experiment by growing Field Madder and another similar relative Hedge Bedstraw Galium mollugo in large pots in a compost mix that should be easy to wash away from the roots at the end of the year.

Large plant pot containing seedlings of Field Madder Sherardia arvensis

Large pot with seedlings of Field Madder.

Hedge Bedstraw Galium mollugo

Large pot of Hedge Bedstraw seedlings.

Dyer’s Woodruff Asperula tinctoria

Over the winter I managed to get hold of some seeds from Rühlemann’s in Germany but unfortunately none of these have thus far germinated. As a native of the northern steppe lands of Europe and Asia this may mean they need vernalization. Some of the plants we obtained from Scottish plant nursery (Poyntzfield Herb Nursery)  died towards the end of last year. Plants placed in an ericaceous compost in tubs seemed to do better than those planted in the chalky soil of our Nature’s Rainbow dye garden. This goes against the generally accepted advice that the plant likes alkaline soils. However, It may be other factors were involved. All of our plants died back really quite early in the year and we were afraid they might die out altogether, but back they have come this Spring and they look quite healthy. They have reappeared at the edge of the planters, showing that last year they tried to expand by producing underground stems much like Common Madder. I guess that this means they are capable of also being quite invasive!

Feathery Green shoots of Dyers Woodruff Asperula tinctoria

New shoots of Dyer’s Woodruff in the alkaline soil of our dye garden.

Ladies Bedstraw Galium verum

This plant has done really well in a whole variety of settings and soil types. It’s also very well behaved with minimal spread. It looks good throughout the year, with pretty clumps of feathery foliage followed by a spray of small yellow flowers in the summer. With its historic interest as a bedding straw, its use in dyeing  and its versatility as an ornamental garden plant, I feel that this plant is a must for any dye garden.

Feathery green clumps of Ladies Bedstraw Galium verum growing next to the greenhouse.

Clumps of feathery green Ladies Bedstraw growing by the greenhouse.

Alder Buckthorn Rhamnus frangula & Purging Buckthorn Rhamnus cathartica

Alder Buckthorn Rhamnus frangula. New shoot showing "alder " shaped leaves and blossom buds.

New growth of Alder Buckthorn.

New growth of Purging Buckthorn Rhamnus cathartica

New growth of Purging Buckthorn.

We tried planting Alder Buckthorn, an acid soil loving shrub, in a variety of conditions. Those planted in ericaceous beds or tubs have done well but those planted out in a wild setting in the chalk soil here have suffered greatly, though it has to be said, the most damage was done by muntjac deer who clearly have a liking for it.
The Purging Buckthorn did less well, to my surprise. It’s not supposed to be fussy about soil type. No casualties, but the plants have not grown very much in the last year. Although it could be that this plant simply takes longer to get established. The new growth this year looks a lot better.

As yet the plants are too small to risk any harvesting but I suspect it is the Alder Buckthorn that will give the better dye.

Tibetan Madder Rubia Cordifolia (Indian Madder or Munjeet)

We are now the proud owners of one of these plants. Obtained from the German Herb nursery Rühlemann’s, this plant spent four and a half days in a box being transported across Europe, the English Channel and finally to our door and arrived in perfect condition! Many thanks to Rühlemann’s  for doing such a professional job of packaging it up, we have great admiration! The growing tips had faded a little during transit but greened up rapidly on exposure to light.
According to the literature these rather elegant looking plants should just be able to survive outside in the UK, though I’m not taking any chances until I’ve had a chance to propagate some cuttings.  At first sight it looks quite different to Common Madder but it has the same leaf whorls (but only 4 leaves to a whorl as opposed to Common Madder’s 4 to 6) and has hooks on the square and weak stems just like madder and cleavers. It obviously has the same growing strategy i.e. it clambers over other plants, holding on with its small hooks.

Tibetan Madder Rubia Cordifolia (Indian Madder or Munjeet)

The Munjeet plant about a week after arriving. Repotted to a larger pot and already starting to grow and looking very healthy indeed

Rubia Cordifolia plant just after delivery and repotting

Rubia Cordifolia plant just after delivery and repotting

We are ridiculously excited by this latest acquisition and look forward to see how it grows and what sort of dye giving roots it has. According to Cardon* its chief dye substance is munjistin which gives a very bright orange. Like common madder it also contains many other dye stuffs, including a very large range of yellow to red anthraquinones. Alizarin is present but only in small amounts so the overall light fastness is probably not as good. Cardon mentions that there are different varieties of cordifolia as well as a very closely related species (Rubia akane) that grows in Japan. Our plant is advertised as being from Tibet, so hopefully it will be able to cope with frost during the winter.

Self-seeding

Bed of hundreds of tiny self seeded Weld seedlings

A mass of tiny self-seeded Weld seedlings in the dye garden

Cota tinctoria

Self-seeded Dyers Chamomile seedlings

 

Madder Seedlings Rubia tinctorum

This year we have had a number of self-seeded Common Madder seedlings in planters positioned near the house. They have produced seedlings in the garden during the Autumn before now, but these usually die during the winter. I think the weather has been just right this year to encourage spring germination and the temperatures near the house have prevented any frost damage.

 

 

 

 

 

Finally a little note on self-seeding of dye plants. We have always tried to encourage plants to self-seed in our garden, with some success. We have been growing the plants for a long period now and the soil is loaded with seed. Weed plants have been under control for several years, so there should be nothing to stop those plants which can self-seed from doing so. So here’s a check list of what you need to do to follow suit:

  1. Allow your plants to flower and drop their seeds. This can produce, in some people’s eyes, an untidy garden but there are so many advantages including encouraging wildlife and saving your time growing the plants from seed and planting out every year.
  2. Keep your garden weed free.
  3. Dig your garden sparingly, preferably in the Autumn or Winter.
  4. Learn to recognise dye plant seedlings.
  5. Use mulch sparingly i.e. only on areas where you intend to plant out other plants. (Mulch supresses seed germination and encourages slugs and snails).
  6. Try and control slugs and snails. (I recommend organically approved slug bait [Iron phosphate] as a last resort).
  7. Water the bare soil if it becomes very dry.

Three varieties of Japanese Indigo Persicara tinctoria

Finally I have managed to sow all three varieties of Japanese indigo at the same time to complete our comparative studies (see blog post). Sure enough, it is possible to tell the difference between the long leaved variety and the broad leaf variety. Even the photos show the slight difference in foliage colour (the broad leaf being a more yellow green) and the long leaf plants are a centimetre or so taller. These plants are about 3 weeks old and grown under identical conditions. The intermediate variety more closely resembles the broad leaf.

Persicara tinctoria

3 varieties of Japanese Indigo at three weeks from sowing.

More Pests

We have found something that eats madder.

Rubia tinctorum pests

This is probably the caterpillar of the Orange Underwing moth, a known pest in the UK which eats a whole variety of plants. So we’re not surprised it’s had a go at our Common Madder. Fortunately there are not enough of them to do any real damage, but they do spoil the appearance of the plants. We can live with that, so no need to take any action.

Suppliers

Rühlemann’s herb nursery has an excellent collection of dye plants and seed for sale and don’t mind sending stuff to other European countries. Their service is excellent.

Poyntzfield Herb Nursery   Scottish herb nursery sells various dye plants and will sell Dyer’s Woodruff root cuttings. Recommended.

References

* Dominique Cardon, Natural Dyes : Sources, Tradition, Technology and Science   . The Definitive reference book of dye plants and dyeing. If you want to know what dye plants are native to the country you live in you will find the information here. A master work, expensive but worth every penny.

Our back garden

The Natures Rainbow Garden

Would you like to take part in a Nature’s Rainbow “Pilot” Workshop on Planning a Dye plant garden?

Planning and Planting a Dye Plant Garden

UPDATE 9 May 2019
Thank you everyone! We have been overwhelmed by the interest shown in this first pilot workshop.  If you would like to be added to a waiting list in case anyone drops out, or if you would like us to alert you about future courses, please get in touch.

We will post about how the workshop goes after 1st June.

_________________________________________________________________________

Saturday 1st June 2019, 1 – 5pm

Creating a planting plan for beginner dye gardeners, with tips from Susan and Ashley of Nature’s Rainbow. What plants to grow, when to plant, when to harvest, how to maintain the garden.

We have been growing and using dye plants in the historic town of Hitchin for over 14 years.
Help us to design future workshops to share our expertise.

5 places available. Contact us via this blog for further details and how to book.
£20 nominal fee required in advance to confirm your place.

This is a very reduced rate to recognise the fact that the views and feedback from the people attending will be helping to design a future workshop for Nature’s Rainbow.

Participants will have a tour of an established dye garden (as featured in The Journal of Weavers Spinners and Dyers https://www.journalwsd.org.uk/article/the-dye-plant-garden and hear how we manage the mix of annual, biennial and perennial plants within the constraints of our site. We’ll structure the session loosely, so we can maximise the flow of info between us all.

Seeds and perennial root cuttings of madder and small dyer’s broom plants to take away.

In exchange, you need to be willing to provide feedback and ideas on how to design future workshops and bring a simple sketch of your growing space, marking up sunny and shady areas and soil type.

Our house and dye garden is a very short walk from Hitchin Station, with frequent services on the Great Northern train line between Kings Cross, Cambridge and Peterborough.  Please contact us

Susan and Ash

Whats New in Natural Dyeing

Exciting new publications for plant dyers

Beyond Mordants from Slow Fiber Studios

Susan and I have long been fans of Michel Garcia’s DVDs on natural plant dyes and pigments. So we were excited and delighted when we got an email before Christmas from Slow Fiber Studios asking to use some of our dye plant photographs for a new DVD:

Beyond Mordants: Indigo Intensive and direct application of Dyes. Film IV: Natural Dye Workshop Series with Michel Garcia

Publication date: February 2019.Michael Garcia and Slow Fibre Studios new DVD Beyond Mordants

Using metallic salts of Aluminium, Iron or Copper for mordanting is controversial in craft plant dyeing as these are all toxic to some extent, both to humans and other forms of life. If used and disposed of with care, the risks can be reduced [See Carrie Sundra’s blog] but many people choose to avoid using metal-based mordants completely.

As a result there has been growing demand to find safer alternative “bio mordants”. Promising plant substances include Myrobalan, various tannins, Curcumin (from turmeric) and Lawson (from henna). In this latest DVD Michel Garcia addresses this gap in current knowledge and shows how to dye and print without using metal mordants.

Slow Fiber’s DVDs are packed with information and can be watched over and over again. They are aesthetic, gentle, informative and a perfect antidote to a stressful world. A friend, Aviva Leigh from Norfolk was the first to introduce us to their work. She says the mark of a true plant dyeing friend is someone with whom you can, with eager anticipation, settle down for an evening of re-watching Michel and Yoshiko’s DVDs, just as others would watch the latest Hollywood blockbuster! The films are soul-food for the craft plant dyer.

It’ll be very exciting to see plants from our dye garden (our babies!!) on screen!

Michel Garcia. Still from DVD “Beyond Mordants” © Slow Fiber Studios

 

New Book: The Art and Science of Natural Dyes

If, like us, you are keen to understand the science of plant dyeing and mordanting in particular, a new book by Catherine Ellis and Joy Boutrup’s comes highly recommended.

The Art and Science of Natural Dyes: Principles, Experiments and Results by Joy Boutrup and Catharine Ellis.The Art and Science of Natural Dyes by Joy Boutrup and Catherine Ellis

This book has now been released for sale (January 2019).

Catharine Ellis is a weaver, dyer and author of international repute based in North Carolina. She specialises in systematic experiments in her craft and teaches through Slow Fiber Studios. Many readers will be familiar with Catharine’s excellent website (see here). Joy Boutrup, from Denmark, lectures in textile technology for fashion design and for museum conservation. Both women have longstanding and impressive careers in their respective fields.

It’s our feeling that both the DVD and this book will be landmark publications, marking a step-change in the systematic knowledge available to the craft plant dyer. So don’t be put off by the prices (Beyond Mordants $52, The Art and Science of Natural Dyes $60).

In our own small way, we hope that the observations that inform our blog are a useful information source, and it’s free! But essentially we provide small snippets of data. Collecting all of that information together into a structured form, providing an expert overview and binding it into a professionally referenced book or instructional DVD takes time and money.

It is my hope that one day I will have amassed enough information about growing dye plants to make it possible to write a book on the subject myself but it will take many more years of growing, observation and experimentation to get to that point.

I can only imagine how much work has gone into the two publications above. Even though I haven’t seen them at the time of writing, I feel confident to recommend them. They are the work of leading experts in the field and I for one can’t wait to get my hands on them!

By Ashley Walker and Susan Dye
© Nature’s Rainbow

Coreopsis tinctoria in flower

Dyers Coreopsis grown as a biennial

Coreopsis tinctoria

By Ashley Walker
Copyright 22nd Jan 2019

In our 2016 post on Growing Dyers Coreopsis (see here) I mentioned that this annual dye plant was considered to be hardy and could be grown as a biennial (seed sown in first year for flowering in second year). I can now confirm this to be true.

Last year we noticed some self-seeded coreopsis growing in pots in the early spring. They had reached quite a size so must have started growing in the late Autumn of the previous year and somehow survived the winter. They went on to produce very attractive early flowers. This year we have some further self-seeded coreopsis plants growing in some of the pots in our back garden which I’ve been keeping an eye on to see how they are weathering the winter. Two nights ago we had a hard frost (about -3°C) and the plants looked quite frozen the following day and stayed that way until another night had passed when they thawed out again. The plants have appeared to recover well (see photos).

Coreopsis tinctoria a hardy biennial

Frosted Dyers Coreopsis plant 20th Jan 2019

Coreopsis tictoria seedling

Two days later on 22nd Jan 2019 the plant has thawed out without any significant damage. What damage you can see has been caused by slugs and snails.

I should not be surprised of course as these plants grow in the North American plains where frost at night in the spring and harsh winters will be a feature of the climate. I suppose that what did surprise me was that left to their own devices the seeds will germinate in Autumn and survive much harsher winters than we get here in the UK. They are after all quite delicate looking plants. This particular plant has a long stem and possibly would not survive a heavy fall of snow but some of the coreopsis we grow have short stems and go through a rosette stage which is an adaptation to over wintering.

Autumn germination does explain why we do not get much self-seeding in our dye garden. Many of the seeds probably do germinate then (when I’m not really paying attention) and are quickly chewed up by slugs and snails which are abundant at this time of year. Only a few seeds are left to germinate in the spring and they too have to run the risk of being eaten.

When we first started growing coreopsis we had no self-seeded plants for many years but in the last few years there has always been a few so I assume the “seed bank” in the soil has reached a level where there are enough spring germinating seeds to ensure some survive. The plants I noticed overwintering are all growing in pots where they do get some protection from the rampaging molluscs – even so you can see by the photos that they have been nibbled.

Coreopsis tinctoria pot grown

Self Seeded and overwintered Dyers Coreopsis in flower in Early July 2018.

So my advice for other growers who desire the stunning displays of coreopsis earlier in the year is to sow seed in the Autumn in an area of garden that you can easily protect from slugs and snails. My plants have survived -3°C but I do not know the lowest temperature they could survive in so if you are in an area that gets prolonged periods of sub-zero temperatures I would also make sure your plants are at least partially protected by placing them near to a warm house or growing in a greenhouse or cold frame.Coreopsis tinctoria in flower

Natures Rainbow new plants 2018

The Natures Rainbow Garden 2018 – Part Two, New Plants

By Ashley Walker
Copyright August 2018

Introduction

Since the industrialisation of synthetic dyes most of the knowledge of plant dyes was lost in Europe until it was partially revived by craftspeople like Ethel Mairet and Later Jill Goodwin, Hetty Wickens, Jim Liles, Jenny Dean and many others. Jill Goodwin lists 140 dye plants alone in her book “A Dyer’s Manual”. Reading the books of these trailblazers has given me an almost obsessive interest in some of these plants – how to grow them, how they are related, what dyes do they have in common etc.  In today’s plant dye world we seem to have concentrated on just a handful of key plants (such as Madder, Japanese indigo, and Weld) which give the best and most light fast colours. People still like to try dyeplant materials that are easily foraged and some of these produce good colours, but many are short lived. Personnally I think that foraging in an already over exploited environment is a practice that should be avoided if possible and I want to grow the plants myself, find out more about them, what they look like, how they grow, what sort of conditions they like, how closely related they are, what pests eat them etc. Natural dyeing is a step on the way to connecting with our precious environment and finding out about and growing the plants we use is another step.

Some while back I realised that Common Madder has a host of relatives, some of which are actually native to the British Isles. As you would expect with close relatives, these plants are similar in appearance and habit. They are all clambering or creeping plants with weak, square stems and thin spikey leaves which usually grow in whorls from the stems.

There follows a list of some of the experiences I’ve had with new plants this year starting with relatives of Common Madder. Where possible I obtained seeds and started them indoors in seed trays in March/April, planting out in May.

Dyers Woodruff – Asperula tinctoria

Asperula tinctoria

Dyer’s Woodruff

Asperula tinctoria

Dyer’s Woodruff in flower

I was unable to obtain any seeds for this madder relative so I was very pleased to discover a Scottish plant nursery (Poyntzfield Herb Nursery)  selling the plants. In March, they sent a big bundle of bare rooted plants wrapped in sphagnum moss.  But as we were then still experiencing freezing and wet conditions I potted up the thick red roots in some ordinary potting compost. Most of these have grown well but a few died after initial good growth. There remain a few which are struggling with yellow brownish foliage even though I planted them out in a variety of soil types. I’m not at all sure what the problem is. Dyer’s Woodruff is an attractive feathery plant similar to its relatives with two to four small thin leaves at intervals along its stem. Small white flowers appeared in June. Now in early August it looks as if a tiny few are developing seeds, which I hope I’ll be able to save. The roots are not as large as madder but they are quite respectable and I’m thinking that of all the new madder relatives we obtained this year this is the most promising. The books say it will grow in acid and alkaline soils and can also grow in partial shade. I’m testing this out.

Ladies Bedstraw – Galium verum

Galium verum

Ladies Bedstraw in flower

Galium verum

A clump of young Ladies bedstraw plants will grow into a cushion and then a carpet.

This plant is native to Hertfordshire and happily grows in chalk soil meadows. It will also grow in many other conditions, including poor sandy soils. The leaves are smaller than Dyer’s Woodruff but have whorls of six leaves at intervals along its stem, much like madder. This plant has grown from seed very robustly. I planted seedlings out in clumps of 15 to 20 creating very attractive cushions of feathery green foliage. These have  grown into ground covering carpets with flower stems reaching 6-12 inches high, with tight clusters of pretty yellow flowers in July/August. It makes an excellent trailing plant and although the flowers don’t last long it would make an attractive contrast to some more showy flowers. In the wild this plant is very competitive and will happily grow in grassy meadows. Tended and watered it responds very well, producing long lasting carpets of foliage. Wild plant roots are thinner than Dyer’s Woodruff so I’ll be interested to see if cultivation makes a difference.

Field Madder – Sherardia arvensis

Sheradia arvensis

An agricultural weed, Field Madder, is a small creeping annual plant with thin roots.

This is a classic annual weed of agricultural areas producing small creeping plants with tiny pale pink flowers, leaf whorls of from 4 to 6 leaves looking very much like miniature madder leaves and large seeds which are produced very quickly. It’s difficult to see how this could have been used as a dye plant considering its small size, short life cycle and thin roots. The books say it was used, so I thought I’d give it a try. Seeds are not too difficult to obtain but do not readily germinate – they have a typical weed habit of staying dormant in the soil maybe for years waiting until the conditions are just right. They do produce a mass of roots so it could be worthwhile. I think that the key to obtaining an easy harvest would be to grow it in pots in good quality compost that could be washed away when the roots have grown. I do not know how much of a problem weed these plants are but they do seem to like growing with other plants which they use for support and do not do so well on their own. They are supposed to be good self seeders so we will see.

Devils Bit Scabious – Succisa pratensis

Succisa pratensis

Rosettes of Devil’s Bit Scabious planted around an Alder Buckthorn sapling in a specially created acid soil bed. There are also some first year weld plants bottom right.

Succisa pratensis

Devil’s bit scabious flower

This is a plant I’ve wanted to grow for a long time for its ability to attract bees and other pollinators. In addition, its pin-cushion-like flowers are a pretty lavender blue and open out in July to October at the same time as many of our yellow flowering dye plants. Growing some plants with a contrasting flower colour has been a bit of an obsession for us. Yellow is nice but needs contrasting colours to really bring it out so I was delighted to discover that the Devil’s Bit Scabious is also a reasonable dye plant, at least according to Jean Fraser in her book Traditional Scottish Dyes where she gives a recipe for greenish yellow with alum mordanted material. Intriguingly she also notes that according to Ethel Mairet the leaves of the Devil’s Bit plant also contain indigo, but I’ve read that before about Weld and that turned out to be nonsense.  (I can feel an experiment coming on!).
The plant grows much like woad, producing a thick rosette of large leaves in the first year or two before flowering. It is a perennial but can, according to other accounts, suffer from getting crowded out by more vigorous plants. It is notoriously difficult to germinate from seed – out of about 100 seeds I only managed to get about 4 germinations and, on previous attempts, none at all. Fortunately the plant can be obtained from specialist nurseries and we got some very healthy specimens from Rosybee which have grown very well and two of these have just started to come into flower.

Shrubs and trees

Alder Buckthorn – Frangula alnus

Frangula Alnus

Alder Buckthorn

Alder and Purging Buckthorn are often sold as hedging plants. They can be found growing in the UK countryside provided you know what they look like. And there is the rub! They look pretty much like a whole load of other small trees so part of the reason we decided to buy some saplings was to familiarise ourselves and be able to identify them in the wild. The nursery we bought the plants from (Ashridge Nursaries) were adamant that Alder Buckthorn could not be grown in our chalk soil so I have put  plants in different soils and environments to see how they get on. They arrived bare-rooted in mid March, after the late freeze relented. I heeled them in compost in a sheltered spot on the patio at home until planting them out in April. So far the best growth has been achieved on the allotment, planted in a special “acid” bed made by piling up and digging in ericaceous compost to the light chalk soil. Second best growth is in a large garden planter filled with a mixture of ericaceous and ordinary compost. The last 2 were planted into a cleared grove of Blackthorn growing on chalk soil without any compost, or any watering for that matter. Needless to say these two have not grown much at all, but they are still alive despite the drought and alkaline soil, so we will see. The bark and leaves of this and Purging Buckthorn are usually cited as sources of yellows to dark brown dye stuffs with “sap” green coming from the unripe or ripe berries (different sources give different information). Of the two species, Alder Buckthorn seems to be the main dye plant but I have been unable to find any direct comparison. Another experiment that needs doing!

Rhamnus cathartica and Frangula alnus

Purging and Alder Buckthorn roots are quite different. Black roots of Purging on left and red roots of Alder on right.

Purging Buckthorn – Rhamnus cathartica

Rhamnus cathartica

Purging Buckthorn

Very similar in appearance to Alder Buckthorn but supposedly  equally happy on acid or alkaline soil. I planted most of the saplings on chalk soil at my apiary and left them to fend for themselves. But I saved one sapling to try out in an acid bed, on the allotment (near the Alder Buckthorn) but it has not grown as vigorously and the leaves have gone yellow in places.

Both Purging and Alder Buckthorn are serious invasive pests in the United States and Canada and are banned in two US states.

Black or Quercitron Oak – Quercus velutina

Quercus velutina

Black Oak sapling

This is a large tree from central and eastern USA which became a very important commercial source of yellow dye in Europe in the 19th Century, even after synthetic dyes started to dominate. We have read a fair bit about this tree’s splendid history and that of the man who promoted it (Edward Bancroft – scientist and spy) and thought we would try and grow it mainly out of historical curiosity. Despite a warning found in one dye book that you could not grow it in the UK, we found a supplier in Cornwall (Burncoose Nurseries). So we are now the proud owners of a small sapling growing in a large planter in our back garden. It will be great to see if we can get some dye stuff from the inner bark but, let’s face it we might be long dead by the time the tree is big enough to harvest a branch or two!

Smooth Sumac – Rhus glabra

Rhus glabra

Smooth Sumac in flower

Of all the different species of Sumac, we decided on this North American one for several reasons. It’s perhaps one of the most decorative,  it is wildlife friendly and also fully hardy. It has a high tannin content and the berries it produces are said to be edible. It can produce invasive underground suckers so we are growing it in a large planter. There are plenty of other sumacs growing in peoples gardens and in waste areas around Hitchin but it’s nice to have one right there in the back garden – no foraging needed.

 

 

 

 

 

Hopefully in a year’s time we’ll have some dyed samples to show how successful these new plants have proven to be.

References

Traditional Scottish Dyes  by  Jean Fraser

A book on vegetable dyes by Ethel M Mairet

Edward Bancroft Scientist, Author, Spy by Thomas J. Schaeper

A Dyer’s Manual by Jill Goodwin

Natural Dyes for Spinners and Weavers by Hetty Wickens, A batsford craft Paperback.

The Art and Craft of Natural Dyeing, Traditional recipes for Modern use by J. N. Liles

Suppliers

Rosybee – Plants for bees http://www.rosybee.com

Poyntzfield Herb Nursery  http://www.poyntzfieldherbs.co.uk

Ashridge Nurseries https://www.ashridgetrees.co.uk

Burncoose Nurseries https://www.burncoose.co.uk

Rubiaceae. Rubia tinctorum, Sheradia arvensis, Galium verum and Asperula tinctoria

Ladies Bedstraw intergrowing with Field Madder and Dyer’s Woodruff. Top left is some Common Madder.

Persicaria tinctoria indigo extraction experiment

Hot vs Cold indigo extraction from fresh Japanese Indigo leaves

By Ashley Walker
Copyright 6th August 2018

Currently the main method of indigo extraction in use on internet Facebook pages is the 2 -3 day long soak in water. I believe this was the main method used commercially in the days before synthetic indigo wiped out the western market for natural indigo. Originally used to extract indigo from Indigofera tinctoria it is still used for small scale production in South Asia. The method is now used for Japanese indigo presumably because the traditional Japanese Method of composting the leaves is too large scale and time consuming for craft dyers. So it has been with some bafflement that I’ve seen the rise of this soaking method as I have always followed the Jenny Dean method which is even quicker.

We were introduced to plant dyeing through the pages of Jenny Dean’s “Wild Colour” and have used her recipe from this book for many years. It involves heating the leaves and can be done in two hours. Since we started to use this recipe we have tweaked it somewhat, discovering that there is no need to heat the leaves over 75 to 80°C to get maximum extraction. Another wrinkle is the need to allow the heated leaves to cool fairly rapidly. Large containers holding 20+ litres tend to cool too slowly and the indigo can be damaged. We did try one experiment when we cooled the extraction bath artificially but that was too quick and the results were very poor. An ideal extraction would be to heat about 1kg of leaves in 5 to 10 litres of water to 75°C and allow it to cool naturally over an hour. In our climate it will fall to around 40°C or less during that time.

So, now to the experiment which was a bit slap dash, but I am sure that it was systematic enough to have fairly good validity for a home dyer.

I picked just over 2kg of fresh Japanese Indigo of the Long Leaf variety which was showing no signs of any flower buds. This was divided into 2 lots of 1026g.

Persicaria tinctoria

Long Leaf Japanese Indigo showing leaf curl – a result of prolonged hot sunny weather.

Hot Soak Method (based on Jenny Dean)

Once batch of leaves was added to a large pan with about 8 litres of cold tap water (20°C) and then gradually heated with constant stirring to 75°C. This took exactly one hour and at the end the leaves had lost all of their fresh green tint and had turned almost black. The water was a very dark grey (a lot darker than usual in fact and I attribute this to a higher than normal amount of indigo in the leaf – a result of the weeks and weeks of hot sunny weather we have had this summer).

The leaves were then left to soak for one more hour, after which there was an indigo bloom at the surface and the water had darkened further. The leaves were removed (by straining through old tights) and 4 tablespoons of household ammonia were added with an immediate colour change to dark yellow/green. The liquid was then oxygenated by pouring from bucket to bucket about 20 times during which the liquid darkened to a green black. A small quantity of the liquid (viewed from above in a white plastic cup) looked olive green.

Indigo extraction from Japanese Indigo Hot and cold methods

Comparison of Hot and cold indigo extraction after 1 hour of soaking but before straining.

Cold Soak Method

The second batch of leaves was placed in a plastic bucket filled with about 8 litres of hot tap water (57°C). I used hot water because I did not wish to wait more than 24 hours. At this temperature the leaves become slightly cooked and release cell contents into the water quicker. The bucket was then set aside for 24 hours. After 1 hour the temperature had fallen to 44°C, the leaves were still quite green and the liquid was much paler and bluer than the hot extraction at the same stage. See image above.

After 24 hours the leaves were still greenish, although they had darkened somewhat. There was a lot of indigo scum on the top leaves. The liquid was grey with a blue tint. The plastic bucket was stained blue. Generally the results so far looked good, with much more blue visible than in the Jenny Dean method.

Indigo extraction from Persicaria tinctoria

Cold indigo extraction after 24 hours. Lots of indigo bloom on leaves.

Indigo extraction from Persicaria tinctoria

After leaves are removed, alkali (ammonia) added and liquid aerated.

Extraction of indigo from Persicaria tinctoria

Comparison of colour of water after extraction.

Leaves of Persicaria tinctoria after indigo extraction.

Colour of leaves after cold soak for 24 hours.

 

Indigo stained bucket

Empty plastic bucket used for 24 hour cold soak now stained with indigo.

The leaves were removed and about 4 tablespoons of household ammonia were added and the colour immediately changed to yellow green. The liquid was then oxygenated, by pouring back and forth between buckets about 20 times. During this process the liquid darkened until it was nearly black. A small quantity looked blue/green.

Dye test

Both extracts were then heated at the same time in separate pans to 50°C, the ideal temperature for dyeing wool, and spectralite reducing agent (thiourea dioxide, thiox) was added (one and a half teaspoons) to each pan. They were then left for about 2 hours to give ample time for the indigo to be reduced. The pots were then reheated to 50°C and an identical skein of wool (Corriedale) was added to each. Both pots were then gently stirred to promote even dyeing and the skeins were removed after 20 minutes.

Results

Initially the colour of the skein from the Jenny Dean (hot) method looked darker but on drying no difference could be detected.

Dye test. hot and Cold extracted indigo from Persicaria tinctoria

Test dye showing relative strengths of dye bath from Hot and Cold extracted indigo.

Conclusions

The amount of indigo extracted appears to be the same for both methods. However, heating, cooking and stirring the leaves increased the amount of fine particulate plant material in the liquid which increased the amount of sludge in the bottom of the dye bath.

I should clarify I don’t use lime (as a combined alkali and flocculating agent) to obtain a dried indigo pigment from my dyeplants. Any indigo I don’t use straightaway for dyeing, I store as liquid sludges. But I can see that for people who do use lime, the cold soak is advantageous because the resulting indigo pigment would contain fewer impurities than the hot soak because the liquid extract after straining is purer. For myself I’m quite happy to continue using my modified Jenny Dean process as it is fast and reliable.

Postscript

Out of interest I also decided to compare the Long Leaf Japanese Indigo to Woad. I processed a similar quantity of Woad leaf according to the 24 hour soak method in the experiment. Another wool skein was dyed in nearly identical conditions and the results prove to me that Woad can actually produce more indigo than Long Leaf Japanese Indigo.

Wool dyed with indigo extracted from Persicaria tinctoria and Isatis tinctoria

Comparison of strength of indigo extracted from Long Leaf  Japanese Indigo and Woad.

A note on alkalis

There has been a lot of controversy about which alkalis produce the best results. I have tried most of them and found that what is important is the pH not the exact chemical used to get there. Washing soda is the weakest and produces very poor results. Household ammonia is excellent and relatively safe, provided you don’t get it on your skin or breathe it in. Calcium hydroxide (lime) is good and has the added benefit of soaking up the indigo precipitate and settling it to the bottom fast (flocculation). Sodium hydroxide is also good but is very corrosive – a danger to skin and textile.
Whenever using strong alkalis you must take safety precautions: wear gloves; avoid splashes; don’t ever add water to dry alkaline powders or granules, add the powder to water; label colourless solutions and store safely; never leave sodium hydroxide solutions unattended for curious animals or children to explore (it is colourless and odourless and very corrosive indeed).

References

Wild Colour by Jenny Dean

Susan Dye and Ashley Walker

The Natures Rainbow garden 2018 – Part one

by Ashley Walker
Copyright August 2018
Banner photograph copyright Sharon Cooper

On the 9th August, after two months with barely a drop of rain, the heatwave and drought in the South East of England may finally have come to an end. Despite regular watering the unnatural weather has taking its toll on our dye plants. For the first time our woad plants are being eaten by Cabbage White butterfly caterpillars (Large White Pieris brassicae and Small White Pieris rapae) and more recently by flea beetles (genus Phyllotreta). I guess the critters were getting desperate to find plants with a bit of juice in their leaves. The weather is having an impact on me as well, I have to water the indigo nearly every day and keeping the rest of the garden needs water too so I’m spending hours each week that I’d rather be spending on writing or dyeing.

This is the first part of a two part post on observations of the dye plants in our garden. This one deals with the plants we have been growing for more than a year. The second part will cover new plants.

European Woad – Isatis tinctoria

Isatis tinctoria being eaten by Large White butterfly caterpillars

These Large White caterpillars managed to eat the whole woad leaf, leaving only the midrib behind.

We have grown Woad for about 12 years now and for the first time our plants have been attacked by caterpillars and flea beetles. This makes a change from the usual small black slugs which put a few holes in the leaves but seldom do any serious damage.

Isatis Tinctoria leaf with eggs and lava of Large Cabbage White butterfly

A cluster of Large White butterfly eggs on the underside of a woad leaf

Isatis Tinctoria being attacked by Flea Beatles

Shiny black small Flea Beatles can slowly chew their way through a woad leaf leaving it like a sieve.

Isatis tinctoria

Woad flower spike August 2018 – from seed to flower in one season as a result of pampering.

I expect that the extraordinary hot weather is to blame with the butterflies and beetles probably acting in desperation. Although the flea beetles appear to thrive, the caterpillars have had a much harder time digesting the unpalatable leaves and most of the newly hatched critters have simply died, leaving a few small holes in the leaf. Only one plant had its leaves reduced to its midrib but even this one will survive as it is now putting out new growth. Interestingly it appears to be only the plants I have watered which are being eaten. There are a few plants which never get watered and these are looking fine.

A few people have asked about growing Woad in tubs or containers and this year we’ve had a few in containers ourselves and this has revealed a problem. One of our plants grown in a container in good compost and watered and fed regularly has grown large and is currently putting out a flower spike which will drastically reduce the amount of indigo in its leaves. Its very unusual to see Woad flowering in August so I can only assume we have pampered it too much – given it the ability to grow large enough to flower in one season. So if you are growing Woad in containers don’t give them too much fuss!

Chinese Woad – Isatis indigotica  

Isatis indegotica

Chinese Woad – about as big as it gets before flowering

Isatis indigotica

Planted out in April these Chinese Woad immediately produced flower stems

We have been growing this for two years now, desperately trying to find out how to stop it flowering a few months after planting. From what I’ve read I’m in good company and this is the chief reason Chinese Woad has not caught on as a source of indigo, despite the fact that it could potentially produce as much dye as Japanese Indigo. Some of the literature indicates that botanists think Isatis indigotica is basically just a variety of tinctoria (European Woad). However, if that is so it has evolved away from tinctoria to a considerable extent. Indigotica is clearly adapted to a much warmer climate and although still nominally a biennial it behaves much more like a half hardy annual. It will flower at any time of year, even in winter, so its rosette stage is always very short and the plant never gets very big. The leaves are a paler blue-green than European Woad and its yellow flowers will continue to be produced throughout the year provided the plants are watered and taken care of. Once the plant starts to flower the larger rosette leaves die off leaving only small leaves on the plant which are probably no good for dyeing. According to the Handbook of Natural Colorants, indigotica will be triggered into flowering if the night time temperature falls below 5°C, which makes it almost impossible to grow the plant to any respectable size here in the UK. Even in Mediterranean climates the plant can only usefully be grown in the Summer. From my experience the plant will flower even if you just look at it the wrong way so I’m coming to the conclusion that it’s not worth the effort. It does grow very quickly however and if you were to grow it en masse and harvest the leaves before it flowered it might just provide a return for your efforts.

Another problem with Chinese Woad is its susceptibility to pests. Caterpillars and aphids like it very much and can easily destroy your plants.  And you guessed it, significant insect damage will also trigger flowering. In a mad moment I decided to see if Chinese Woad tasted any nicer than European Woad. But the taste test settled nothing, both plants are extremely bitter and fiery. I obviously don’t have the finer tastes of Cabbage White butterfly caterpillars!

Japanese indigo – Persicaria tinctoria

Persicaria tinctoria - Long Leaf variety

Long leaf variety of Japanese Indigo with curled leaves to protect itself the prolonged hot sun of 2018

This year we are growing the same three varieties as last year – Long Leaved, Broad Leaved and an Intermediate Leaved white flowered variety. There appears to have been no interbreeding from last year. This year the difference between the long leaf and broad leaf varieties is stark. The Long Leaf plant is very vigorous with dark green leaves. The Broad Leaf variety took a long time to get going as usual and suffered from its leaves turning red. I was initially confident that the red colour was partly due to the hot sunny weather we were having in early summer – the slow growing plants were getting roasted. But after a good feed (with chicken manure pellets) the plants started growing quickly with the new foliage a nice mid green despite the continued hot sunny weather. So a bit of a chicken and egg situation: was it the lack of fertilizer that caused the leaves to redden or simply that the young plant leaves, growing slowly, were getting a longer exposure to the hot sun?  The Long Leaf variety reacted differently to the hot sun with leaf curling , something I had seen last year but only on plants grown in the greenhouse.

Persicaria tinctoria

A bed of intermediate White flowering Japanese Indigo.

Persicaria tinctoria

Newly planted out Broad Leaf Japanese Indigo with sun reddened leaves.

Thus far we have only harvested the Long Leaf variety and used it in a little experiment comparing Jenny Dean’s extraction technique with the more often used long soak in cool water. The results will be written up in a later post. What I have also noticed is that we are currently getting a considerably better production of indigo from Woad than the Long Leaf variety of Japanese Indigo. Woad is well known for giving better results when the weather is hot and sunny. If the climate change predictions are correct and we continue to have hot summer weather then I think we would be better to return to growing mostly Woad. The Long Leaf variety of Japanese Indigo produces the least amount of indigo dye of the three varieties (see comparison here) but it does produce larger plants so perhaps still produces an equivalent amount of indigo per square metre.

Madder – Rubia tinctorumRubia tinctorum berries

Once again this year the madder plants are producing masses of berries. This is the third year running. In the previous 10 years or so the plants produced only a few. I have no explanation as to why this is.  I’ve grown plants in different soil, in planters and in the ground and all plants are doing the same. A result of the weather?

Rubia tinctorum

Madder plant obtained from Southwark Cathedral in early 2018.

This year we obtained a new madder plant sourced from Southwark Cathedral dye garden. The plant is quite different to plants I have been growing up to now (all of which were derived from a single seed over 10 years ago). This new plant has paler leaves with a different shape and it flowers about 3-4 weeks later. It will be interesting to see if the root yield is also different. I’m pleased to have been able to increase the genetic diversity of our madder as I’ve always propagated by root stem cuttings or from seeds from my own plants.

Wild Madder – Rubia peregrina

Rubia peregrina

Wild Madder in flower – Early July

We’ve been growing this plant for nearly three years now. It’s an evergreen but the tops do not appear to be totally hardy in the UK climate and were damaged by the winter frosts. This is the first year in which the plants (originally obtained from a wild flower nursery) are starting to look a bit happier. They are putting out new shoots from underground stems and flowering for the first time. It remains however a very slow growing perennial and I think it will take longer than Common Madder to produce a good root harvest so we are leaving it for another year.

I was given some seed from a friend from some wild plants growing on the south west coast which nearly all germinated though it did take well over a month before the first shoots appeared.

Saw wort – Serratula tinctoria

Serratula tinctoria

Saw-Wort plants with yellowing of leaves.

Serratula tinctorum

A self seeded plant with dark green leaves growing next to the transplanted ones with yellow leaves.

This native  plant continues to be disappointing. Not only do the plants remain small but about half of them suffer from bad yellowing of the leaves once planted out in the garden. I have tried practically everything to remedy the problem – fertiliser, Epsom salts and seaweed extract. There are some self-seeded plants which look very healthy so I do wonder if the roots are somehow getting seriously damaged during transplanting. It also remains likely that there is something wrong with the soil itself as other plants (Genista, a red scabious and a Purging Buckthorn shrub) are similarly affected.

Serratula tinctoria dye comparison

A comparison of our main yellow dye plants. Top is Weld, Bottom Right is Genista and Bottom Left is Saw-Wort

We did try dyeing with the Saw Wort this year and obtained a good buttery yellow. We were hoping it would be a nice lemon yellow like Weld and Genista so were a bit disappointed with that too.

Dahlia species

Dahlia Species

Bumble bee on single type dahlia grown from seed.

Dahlia Species

Dark Red Dahlia giving pinky purple and greens. Possibly “Nuit d’Ete” or “Black Cat”

The colour of Dahlia flowers has an effect on its dye but we did not appreciate by just how much until this year when we tried using some deep red flowers to dye with. We obtained nothing like our accustomed strong yellows with acid pH and strong orange with alkaline pH. This time we got green with alkali and blue/purple with acid indicating that the dyes in this dark red flower were the same as you find in red cabbage and some other red flowers. These dyes, although very pretty, are not light fast. Over the years of growing Dahlia we have narrowed down the varieties that produce the best results for the home dyer. These are yellow or orange double flowering pom pom types. The pom pom flowers are longer lasting and produce more dye – some pom poms are very large and yield a lot of dye but bees and pollinators are unable to assess the nectaries. We have tried to stay away from these but there’s no doubt they are the best for dyers.

Tansy – Tanacetum vulgare

Tanacetum vulgare

Tansy needs regular watering for healthy plants.

Often used by Scottish dyers as a source of yellow dye this plant has been growing in our garden for several years now but largely unused because the plant wasn’t very vigorous. There was never enough plant material to harvest and the flowers were disappointing. This year we planted a bed of Japanese indigo alongside so the Tansy benefitted from being regularly watered. The resulting Tansy flowers have been lovely so if you’re growing them keep them watered for best results.

Perennial Coreopsis –  Coreopsis grandiflora varieties e.g. Golden Joy, Sun Ray, Early Sunrise

Coreopsis grandiflora

Perennial coreopsis – plant breeders benefitting the plant dyer.

Coreopsis grandiflora

Bright orange on alum mordanted wool blanket.

These are double flowering perennials with deep orangey yellow flowers which produce a lot of dye. They are not as hardy as the growers would have you believe as half our plants died during the winter and only a few have recovered enough to put on a good show this year. However, many can be easily grown from seed so are not too expensive to grow. They make excellent bedding plants and produce a fabulous orange dye from the flowers. An example of the plant breeders unwittingly aiding the home dyer.

Dyer’s Alkanet – Alkanna tinctoria?Alkanna tinctoria

Alkanna tinctoria

Alkanet root. Bottom tip has had thin outer black bark removed revealing the dissapointingly white root.

This is the third year of growing and though I have not tried to extract any dye from its roots I am deeply disappointed to find that the roots are not red as they should be. I was suspicious as soon as I started to grow the plant from seed bought from the German Company Rühlemann’s. The plant seemed too vigorous with over large leaves and not hairy enough, but I persisted with it until it flowered. The flower shoots were tall (up to about a metre high) and not at all like the creeping wild flower growing around its native Mediterranean. The flowers when they finally appeared were the only part of the plant that looked like the pictures of Alkanna tinctoria seen all over the internet but the roots? The roots were white!

Doing some reading around this ancient dye plant I find that its qualities as a medicinal plant derive solely from the coloured substances in the root which were used as a dye, cosmetic and bio stain so you can imagine the way I feel after lavishing attention on this plant for the last three years only to find the roots are white! Recently I discovered one internet comment on the plant that says the cultivated version of the plant does not produce as much dye as the wild type. Well that’s some understatement. Of course it is possible that lavishing attention on the plant was entirely the wrong thing to do and I should have left it alone but it seems more likely that the growers have simply selected the seed year after year from the largest prettiest plants and in so doing have bred out the qualities that gave the plant its historical value.

Just to confuse matters Alkanna tinctoria has been and is also known as “Anchusa bracteolata, Alkanna tuberculata, Alkanna lehmanii, Lithospermum lehmanii”, and has been given various common names as follows Alkanna Radix, Buglosse des Teinturiers, Dyer’s Bugloss, Henna, Orcanète, Orcanette, Orcanette des Teinturiers, Orchanet, Radix Anchusae. Rühlemann’s who sell the seed are now calling it Alkanna tuberculata. There is certainly confusion on the identity of all these plants. Are they all the same or not. If there are any botanists out there  who can get to the bottom of this please please get in touch!

References

Philip John and Luciana Gabriella Angelini – Indigo – Agricultural Aspects. Chapter 7 of Handbook of Natural Colorants  Edited by Thomas Bechtold and Rita Mussak. Wiley Series in Renewable Resourses. (Available as free download).

Rühlemann’s  This German herb plant and seed supplier has a number of dye plants for sale including Chinese Woad and Long Leaf Japanese Indigo but it is primarily interested in the medical properties of the plants it sells and I get the impression they know little about plant dyeing.

The Natures Rainbow Year – (and its only half way through!)

An article by Susan Dye and Ashley Walker
© copyright 2018

2018 is turning out to be our most successful yet.

The year began with our good friend Brian Bond joining us to deliver a two day workshop in Ipswich in late January with the International Felters Association (see above). Susan was involved in much mordanting in preparation. This was our second major plant dye workshop away from home, and dependent on friends or family to help us with transport. Hard work packing an ‘all singing all dancing’ workshop and the three of us into a single hatchback vehicle (albeit a large one, thanks Brian!). Quite stressful but very well worthwhile, as the students were terrifically motivated and created a full palette of wonderful colour on the finest merino tops.

Also in January we had confirmation that Southwark Cathedral had invited the London Guild of Weavers, Spinners and Dyers (WS&D) to demonstrate plant dyeing as part of London Craft Week in Mid-May. Susan was asked to coordinate the project, having held a successful mini natural dye demonstration there as part of the biennial London Guild exhibition last November.

Preparations for all this activity took place mostly in the winter and early spring when the weather was too cold or wet to work outside on the dye garden

In between scoping and planning the London Guild event at Southwark, Susan gave talks on plant dyeing to the Chelmsford Embroidery Guild, on the red dye from madder for the Cambridge Guild of Weavers, Spinners and Dyers and, closer to home, a talk on the horticulture of dye plants for the Wymondley Gardeners Group. Had the snow in early March not intervened there would have been another talk on the history of Norwich Dyers to region 7 of the Quilters Guild.

London Craft Week event at Southwark Cathedral with the London Weavers, Spinners and Dyers Guild

The Shard overshadows our colour splash at Southwark Cathedral

Susan spent much of April mordanting and test dyeing fabric and yarn for the London Craft Week event, which was to be held outdoors in the Churchyard in mid-May. Fortunately the weather improved and we were blessed with two sunny breezy days. With help from textiles graduate Hannah Sabberton, Susan and I carried Hitchin grown fresh woad and dry Weld, Indigo dye solution, mordanted fabric yarn and fleece, samples, display materials and goodness knows what else (kitchen sink comes to mind!) on the train and bus into Central London at rush hour. We are resourceful public transport travellers with trolleys and backpacks and all arrived safely! Mercifully all the pans and heaters had been supplied by London Guild members based not too far away (thanks to Penny and Diane). Also there were many, many lovely dyers from the Guild who shared the demonstrating. All told there were twenty two volunteers across the two days. We spoke to people from all over the world, from London and other parts of the UK. Tiring but very satisfying to see the rainbow of colours we achieved with just the three medieval ‘grant teint’ plant dyes: Madder, Weld and Woad.

Susan managed to escape a couple of times down to the British Library where she loves to do research on the history of dyeing and in particular the 19th Century “Norwich Red”. An article to be published in the Autumn issue of “The Journal of Weavers, Spinners and Dyers” will detail her findings so far. We have also been asked to write an article on growing dye plants with a particular emphasis on small gardens and container growing. This should appear in the next issue of “British Fibre Arts” along with a profile about ourselves. The Editor Rainy Williamson made us think about what we do and why we do it. I was particularly reminded that many people do not have access to a garden or allotment and may only be able to grow dye plants in small spaces. I immediately set about making and planting up some large-ish containers with suitable dye plants to see how they responded. And then we got to thinking that apart from a couple of small demonstrations and the regular workshops for our local guild we’ve never made an effort to share our skills in plant dyeing with the local population. So Susan quickly got on the phone and asked the Hitchin Festival organisers if they still had some slots left in their programme and lo and behold, (thank you Keith)  we were found a slot in the programme.

Indigo Blue, Weld and Chamomile yellow and Greens produced by overdying yellow with blue and blue over yellow

Results from the green overdye experiment done at the Herts Guild of Spinners Weavers and Dyers Workshop

Meanwhile we had another workshop for our local Guild in North Herts to get ready for. This was based around an experiment investigating the notion that a better green is obtained if wool is dyed first with indigo and then weld (yellow) rather than the other way round as we have traditionally done it. Various accomplished plant dyers had reported this finding and we wanted to check it out. The workshop produced some fantastic greens and, somewhat to our surprise, the blue overdyed with yellow did indeed produce the best green.

While all this has been going on I’ve been working hard on the Natures Rainbow dye garden, getting it into shape to satisfy the North Herts District Council allotment inspector (Grounds Maintenance Monitoring Officer). Because we are growing a most unusual set of crops some of which look remarkably like weeds we

Rubia tinctorum

Madder is closely related to the weed Cleavers or Goosegrass. It looks and behaves much the same but is altogether larger in stalk and leaf and has berries instead of hard seeds.

Ransoms Rec Allotments, Hitchin

The Natures Rainbow allotment plot in early June.

have to make the plot look as tidy as possible. Madder for example is a close relative of the weed Cleavers and has the same sprawling habit and Weld is generally classified as a weed anyway. In addition, we leave our second year Woad plants to go to seed, so we have stock for the following year and this too raises eyebrows.

Asperula tinctoria

Dyers Woodruff in flower

We also decided early on this year that if we are going to continue giving talks and writing articles about growing dye plants then we need to expand our experience and grow some of the more unusual dye plants so we sent off for more seeds including Chinese Woad, Wild Madder, Field Madder, Ladies Bedstraw, Blood Root and where we couldn’t get seeds we ordered plants. These include Dyers Woodruff, Black Oak, and Smooth Sumac (Rhus glabra).

Quercus velutina

Our new Black or Quercitron Oak Sapling. The inner bark of this North American tree produces the dye quercitrin which for a while was a major industrial source of yellow dye. Of course it will be many years before we can harvest any bark from this specimen!).

Reseda luteola

Honey bees are particularly fond of Weld

 

 

 

 

 

 

 

 

As a beekeeper I’m also very interested in growing plants that are also good for all kinds of bees so I’ve been very gratified that many of our dye plants are also fantastic bee plants too, Weld and Japanese indigo are two of the best.

Rhus Glabra

Smooth Sumac from North America, the dried leaves of which contain 25-27% by weight of tannins.

Look out for more blogs detailing some of the events mentioned here but you might have to wait until things calm down a bit before we get time to write them!

Inula helenium

Elecampane – Inula helenium

An article by Ashley Walker
© copyright 2018

When we first became interested in growing and using dye plants we came across an entry in “Traditional Scottish Dyes and how to make them” by Jean Fraser. This seemed to us to be very exciting because it offered a tantalising alternative blue dye to Woad indigo.

Traditional Scottish Dyes and how to make them by Jean Fraser

Page 69 from Jean Frasers book – Traditional Scottish Dyes and how to make them.

Traditional Scottish dyes and how to make them by Jean FraserWe immediately set about obtaining some seeds which were readily available as Elecampane is a popular garden flower and ancient medicinal herb. Our first lot of seedlings were all eaten by slugs but the second batch (protected until they were larger) survived to produce two small beds.

It took a number of years for the plants to reach full size but by this time we had realised that the likelihood of obtaining blue from the roots was very unlikely and we had discovered Japanese Indigo so did not think it worth even trying. We kept the plants because every year we are rewarded with a sunny display of glorious yellow flowers which act as magnets for bees of all kinds. These tall plants with giant leaves are low maintenance and just take care of themselves.

Inula helenium

Honey bee on Elecampane flower.

The Dye garden has grown over the years and we are getting to the point that every plant species we grow has to justify its presence by being a proven source of plant dye. But still, the mystery of Jean Fraser’s entry stuck in our minds so this year I decided to give it a go before the plants started to grow.

Three of the incomplete “no details or quantities given” recipes mention whortleberries and one recipe Elder (presumably berries) as additives to improve the colour. We know by now that most black berries can give pinks, lilacs and mauves with a good alum mordant but they are not lightfast, iron mordants are best at prolonging the life of fugitive dyes and the fourth recipe mentions iron so we thought it worth obtaining some whortleberries . What are whortleberries?

Wikipedia suggests they are one of three possible members of the Vaccinium family:

Vaccinium myrtillus, bilberry, or blue whortleberry
Vaccinium vitis-idaea, lingonberry or red whortleberry
Vaccinium uliginosum, bog whortleberry/bilberry

All three plants grow commonly in Scotland but we think it is a reasonable guess that the name refers to the bilberry V. myrtillis or uliginosum as vitis-idaea is a red berry. The closest source of berries we could get hold of were supermarket blueberries (probably Vaccinium corymbosum). Not as good as our native bilberries as they only have a blue black skin and internal pale green flesh. Our native species are blue/black throughout.

Experiments

Initially we tried a number of variations:

  1. Fresh chopped and bruised roots heated with and without blueberries
  2. Fermented chopped and bruised roots with and without blueberries
  3. Samples of unmordanted, alum mordanted and iron mordanted wool were added to each of the dye pots (the root and berry material were not removed).

The roots of elecampane are white with a yellowish skin and black bark which is not attached to the root and is easily washed off. There appears to be no colour in the root at all!

Inula helenium

Elecampane root

Inula helenium

Elecampane cut root

Because of this lack of colour we had long suspected that the only possible source of colour would be from tannins in the root reacting with the iron mordant to give a grey. We suspected that in Scotland grey was often called blue and with the addition of some whortleberries a bluish grey could be obtained though it would fade to grey over time. As there are many other sources of tannin in the dye plant world we were sceptical that Elecampane root would give us anything worth having.

Results

The results were fairly conclusive in that the only significant colour change occurred with the iron mordanted wool where a silvery grey was obtained from the fresh root and a yellowish grey from the fermented root. The unmordanted wool stayed white and the alum mordanted wool turned a very pale yellow. The addition of blueberries made little difference.

Inula Helenium dyed wool

Right: iron mordanted wool in fresh root dye bath. Left: Iron mordanted wool in fermented root dye bath.

Inula helenium treated woth iron mordant

On the left cut root treated with iron mordant. On the right untreated root.

Painting an iron mordant solution onto cut plant material usually shows up the presence of tannins fairly rapidly but sometimes it takes a few hours to get a colour change. The elecampane root had to be left overnight before the change seen here on the left took place. Other additives mentioned in the recipes are salt and ash. Dipping a cut root in salt had no effect but adding a tiny amount of sodium hydroxide (an alkali in wood ash [lye]) to the cut root turned it immediately yellow and after 24 hours a yellowish dark grey. We did not use any of this alkali in our experiments as we were particularly interested in obtaining a neutral or blue grey but it looks like adding the alkali could aid in getting a darker colour.

Once we were happy we could get this neutral grey we went ahead with dyeing a large skein of hand spun yarn (about 100g) mordanted with 1g of ferrous sulphate*. This was added to a dye bath made from about half a kilo of chopped and bruised Elecampane root heated to around 90°C and left for one hour then strained to remove the solids.

Inula helenium dyed wool

100g skein of hand spun iron mordanted wool dyed with Elecampane root.

OK, so no blue, but a good neutral grey is hard to obtain as most tannin rich plants have additional dye stuffs and the greys obtained are tinted with yellows or browns. Elecampane is almost free of any of these contaminants. As any designer will verify grey has the ability of amplifying adjoining colours making them seem brighter than they really are. A dye garden without a source of grey would not be complete so the Elecampane stays!

Inula helenium

Elecampane in full flower

*The iron mordanting is done according to Liles method using the same quantity of oxalic acid as ferrous sulphate. The Oxalic acid prevents the iron from oxidising from the yellow-green ferrous sulphate to orange ferric oxide (rust).

References

“Traditional Scottish Dyes and how to Make them” by Jean Fraser. Illustrated by Florence Knowles. © 1983, 85 and 96.

“The Art and Craft of Natural Dyeing – Traditional Recipes for Modern Use” by J. N. Liles. © 1990

Persicaria tinctoria

Three strains of Japanese Indigo tested and observations on indigo extraction

An article by Ashley Walker
© copyright 2017

This year I had planned to carry out a tightly controlled experiment to look for variation in the amount of indigo produced by three fairly distinct strains of Japanese indigo. However due to a prolonged and still undiagnosed illness, my plans were thwarted and the experiment did not work out quite as I had hoped. However, on 12th and 13th October 2017, with help from Brian Bond another keen plant dyer, I did manage to complete a test of the three plants although the results are not directly comparable due to different planting times and maturity of each variety.

The strains

Broad or Rounded leaf indigo

Persicaria tinctoria

Round or wide leaved Indigo. Directly sown bed

Grown from seed originally from the USA (from fellow natural dyer Pallas Hubler in Washington State on the west coast) who sent a few seeds over to Brian in 2013. We have been growing and saving seed from this strain ever since so it is possible that it has become adapted to growing in our soil.

  • Late flowering (October into November)
  • Pink Flowers
  • Compact short flower stems
  • Wide short or rounded leaves
  • Foliage pale to mid green
  • Easily damaged by high nitrogen levels in the soil. Grows poorly in cool overcast weather.

Long leaf indigo

Persicaria tinctoria

Long leafed Japanese Indigo in full flower.

Seed for this was obtained from the German supplier Rühlemann’s. Unfortunately this was in full flower by the time I was able to harvest it for the test and from previous experiments I know that once indigo has committed itself to flower production the amount of indigo in the leaf falls dramatically.

  • Large long pointed leaves
  • Pink flowers
  • Long delicate flower stalks
  • Early flower (September-October)
  • Dark green leaves
  • Very tolerant of high nitrogen in the soil and generally more robust.

An in-between white flowered strain

Persicaria tinctoria

Intermediate white flowered Japanese Indigo

Persicaria tinctoria

Intermediate strain of Japanese Indigo with white flower.

The seed was obtained from Lisa George Fukuda a fellow plant dyer in Guernsey who had it originally from Teresinha Roberts at Wild Colours

Unfortunately this was planted out late in the year (August) so as yet I know little about its habit as there has not been enough time for it to grow to full maturity.

  • Longish leaves
  • White flower
  • Easily damaged by high nitrogen fertilizer.
  • Mid green leaves
  • Quickly bushes out, highly branching.

All three strains were grown on the Natures Rainbow allotment in Hitchin in a chalk soil with a strong application of Fish, Blood and Bone plus some chicken manure pellets.

Persicaria tinctoria

Leaves from all three strains.

Persecaria tinctoria

Rounded leaf Japanese Indigo growing with the Long Leaf strain in the greenhouse. Here they look like two completely different species.

The experiment

After stripping the leaves from the freshly cut indigo stalks, 220g of leaves from each strain were slowly heated from room temperature to 80°C in stainless steel pans with 4 litres of tap water. The pans were stirred at short intervals throughout. Note: the weight of leaves was determined by the amount of the long leaved strain that I could harvest from shoots that had not yet come into full flower as I wished to minimise the effect of flowering on indigo production. The amount of water in the pans was deliberately large as I wished the final colour to be on the pale side as variations in pale colours are easier to distinguish. More water also means the pot is easier to stir before the leaves are cooked.

Heating to 80°C took about 35 minutes. The pans were then taken off the heat and allowed to cool, free standing in the air for 1 hour. (The air temperature was appoximately 20°C).

Persicaria tinctoria

Intermediate Japanese Indigo extraction bath with container of liquor to show gray colour. Photo taken just after pan was removed from the heat.

At this point no difference could be noticed between the different pans. The liquor in each pan being a pale greyish blue in each case.

After one hour the leaves were removed by straining through an old pair of tights into a large plastic bucket. Half a cup of household ammonia was then added to the liquor. Taking care not to breathe in hot fumes, this liquor was poured back and forth from bucket to pan 10 to 15 times to aerate and oxidise the indigo precursor to indigo. The colour of the liquor changed from grey to yellow green, with the round leaved plant giving the darkest colour change and the long leaved plant the least. This is a good indicator of how much indigo is present in each pan.

Once oxidised to indigo, the liquor is now in a stable form and can be left for long periods without any loss of indigo. The reduction vats (indigo dye baths) were set up the following day as follows. The pans were heated to 50°C, one level teaspoon of Spectralite (Thiourea Dioxide) was added to each pan, gently stirred in and left for 30 minutes for the indigo to reduce to its soluble form. Identical weight skeins (26g) of wool were added to the baths at 50°C and left for 20 minutes before removal and oxidation in the air. The dye baths were kept in a hay box to maintain constant temperature during the dyeing.

The results

Japanese Indigo

First results showing a surprising difference in colour obtained

The long-leaved plants (left) were disappointing only producing an ice blue colour. The white-flowered intermediate-leaved plant gave a slightly deeper shade but still pale (centre). The round-leaved plant produced a respectable light blue (right).

The poor results for the long-leaved plants was understandable because of their flowering state, however I was surprised the colour was quite so pale. The good results for the round-leaved plant was a real surprise as I had become convinced these plants would not be the best. Overall the pale colours made me worry that I had not optimized the process and I decided to repeat the experiment for the round-leaved and intermediate-leaved white-flowered plants (I had no more of the long-leaved plant so I could not replicate this one).

On the second run I made one change which was to slow the cooling of the extraction bath after reaching 80°C by placing the pans in hay boxes. For this experiment, using 4 liters of water I was aware that this small amount of liquor would cool quickly, perhaps too quickly? An experiment we conducted some years ago revealed that premature cooling of the extraction bath resulted in a dramatic loss of indigo when processing woad leaves. Two years ago we discovered that leaving the bath at a high temperature for more than one hour also results in a loss of indigo so I have become wary of putting large baths in hay boxes which are capable of maintaining a high temperature for hours.

In this second run the results from the white-flowered intermediate-leaved plant improved but the round-leaved plant still produced the better result (which itself was no better than in the first run).

Skeins of wool dyed with Japanese Indigo

Second run with intermediate white flowered indigo plant compared to rounded leaf plant.

Skeins of wool dyed with Japanese Indigo

Comparison of intermediate white flower strains. The difference between quick and slow cooling of the extraction bath.

Wool dyed with Persicaria tinctoria

No real difference between runs for the Rounded leaf strain.

Discussion

In theory all three plants should have produced broadly similar amounts of indigo. That they did not could have been due to genetic differences but as noted above all three plants were at different stages of development having been planted at different times and the round-leaved strain had possibly adapted to the local soil over the 4/5 or so years I have been growing it. The poor results from the long-leaved plant may have been entirely due to their flowering state. The intermediate-leaved white-flowered strain had only been planted out in late August and may not have had sufficient exposure to the sun to develop much indigo.

The diversity of results shows how critical it is to grow and harvest the plant at the right time. I was certainly concerned that harvesting the plants in October was a risk, as all three varieties were producing flower buds (although only the long-leaved plants were in full flower). Later I extracted a concentrated bath of indigo by making up a large pan crammed full of leaves and only enough water to barely cover the leaves when they were pressed down forcibly. The results were pleasingly strong indicating that the leaves were still fully charged with indigo.

Skein on right dyed with a strong indigo dye bath

Skein on right dyed with a strong indigo dye bath

I will certainly be making strenuous efforts to continue to save the seed from the round leaf strain whatever the reasons for the underperformance of the other two strains!

Confirmation of results

Since this post Leena Riihelä writing in her blog (see Riihivilla) has confirmed that the long or pointed leaf variety of Japanese Indigo does not produce as much indigo as the broad or rounded leaf variety. Leena who also grew three strains of Japanese indigo this year also speculates that the broad leaf (rounded) variety originated in Japan. (The long leaf variety may come from Northern Japan or China). She is also able to confirm that the long leaf variety flowers much earlier. Leena is based in Finland which has such a short growing season that the rounded leaf variety does not have time to produce seed. Leena has a wealth of experience to share about indigo and other natural dyes so please visit her blog and web site. (see below)

Thanks to:

Brian Bond
Leena Riihelä at Riihivilla
Lisa George Fukuda
Pallas Hubler

Indigo dyed wool

The range of blues obtained from the three strains of Japanese indigo.