Monthly Archives: August 2018

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.