Dyers Greenweed is a member of the Fabaceae or legume family. It is a typical shrubby broom native to the UK, growing in open pasture and heathland. It is a source of an excellent light fast lemon yellow dye similar to Weld. As its name suggests it was used with indigo (from Woad) to dye textiles various shades of green.
Like some other native dye plants, Greenweed has declined with the rise of modern agriculture so you are less likely to be able to forage for it. It mostly grows in the West and South of England and appears to prefer slightly acidic loamy clay soils though it will grow in alkaline soils if treated well. It can grow to a height of 1 to 2m and forms a bush, usually growing from a single base stem. There are dwarf varieties and a dwarf subspecies Genista littoralis. It is extremely hardy (surviving temperatures as low as -35ºC) so it should be possible to grow it in the far North. It loses its leaves in the winter and this maybe the reason it’s able to stand the sub-zero temperatures. It does not like being waterlogged but struggles in dry soils too when it needs to be watered occasionally during hot summers.
Dyers Greenweed bush growing in the author’s back garden.
The seedpods of Greenweed turn black in late summer and on hot days burst apart scattering the small pea shaped brown seed.
Seeds and pods of Dyers Greenweed
These may germinate in the Autumn or stay in the soil and germinate in the following spring. When I first tried to grow the plant from seed I followed the instructions to plant in the Autumn. Although some of the seeds germinated I found that the seedlings died during the winter. so I changed my strategy to planting in Spring which works very well and allows the seedlings to grow large enough during the first year to get through winter without problem.
Start seeds off indoors in modules or seed trays from March to April and plant out in June in a sunny position.
This very young Dyers Greenweed has self seeded but is in danger of being eaten by slugs.
The plants will grow large, so give them plenty of space and plant about a metre apart. They can be grown as a hedge in which case plant closer (say 20 to 25cm). The seedlings are very prone to slug and snail attack, so sowing the seed outdoors is very risky without protection. Cuttings can also be taken. Cut the woody 1 to 2 year old stems in Spring or Summer and just stick them into the soil. Only about 10 to 50% will take so plant more than you need. They will need watering regularly during the summer as they take a month or two to root.
Pests and diseases
Ladybird to the rescue
Aphid on young shoot of Dyers Greenweed
Apart from slug and snail attack when young, the next big problem is aphids, which attack the young shoots in early Summer just when you want to be picking them for dye. The damage can be extensive and I sometimes have to resort to spraying them off with a jet of water from the hosepipe. Ladybird and hoverfly larvae usually get the aphid under control by mid to late Summer and the plants will recover enough to flower. There appears to be quite a bit of natural variation amongst plants with some consistently being attacked and others being generally free of the bugs. So if you find you have a resistant plant don’t hesitate to take cuttings from it.
Deer and other large herbivores also like to eat Greenweed.
The young shoots are best for dyeing. As the plant gets older it produces fewer shoots so the bush needs to be pruned or cut back at least once a year to encourage this new growth. In earlier times when the plant was grown as a source of dye it was typically harvested in the second year when the whole plant was cut down. During the early Spring/Summer take the first harvest of young shoots then cut back in August to get a second growth and harvest. Growing this plant as a low hedge is ideal.
Dyers Greenweed will regrow quickley after being cut back and produce lots of new shoots.
As a member of the legume family, Greenweed is capable of fixing nitrogen in its root nodules. As a result the plant does not need much, if any fertilizer and can grow on quite poor soils. Don’t plant Greenweed in your most fertile bed, so choose instead any bit of scrappy ground that gets full sun. Greenweed will not grow in heavy shade. Against a South facing wall or fence would be ideal. To help keep weeds down after planting you can add some thick mulch around the stems. Water if the soil becomes very dry.
Greenweed is grown as a decorative garden plant for its bright display of yellow blossom in mid to late Summer. If you grow several plants from seed they will probably have slightly different flowering times but if you buy a commercial cultivar each plant will flower at the same time. Commercial cultivars may also be less able to cope with strong pruning and are usually a lot smaller than the wild plant. Three cultivars of note are:
Royal Gold – 0.5 to 1m
Humifusa – dwarf variety
Flore Pleno – dwarf variety
The leaves and young shoots are treated much like Weld except if the stems are woody strip the leaves first. Boiling water is poured on the cut shoots and left for an hour or so to extract the dye. Fermenting the young shoots can also have excellent results. A small amount of alkali (lime water or a drop of ammonia) will bring out the yellow. Dye your textiles in the resulting extract at around 70ºC. This dye is excellent for silk. If dyeing green with indigo a slightly better result will be obtained if you dye indigo first and then over-dye with Greenweed. The young shoots can be dried for storage and later use.
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
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
Ladies Bedstraw in flower
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
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
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.
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
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!
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
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
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
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.
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
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.
A cluster of Large White butterfly eggs on the underside of a woad leaf
Shiny black small Flea Beatles can slowly chew their way through a woad leaf leaving it like a sieve.
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
Chinese Woad – about as big as it gets before flowering
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
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.
A bed of intermediate White flowering Japanese Indigo.
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 tinctorum
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?
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
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
Saw-Wort plants with yellowing of leaves.
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.
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.
Bumble bee on single type dahlia grown from seed.
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
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
Perennial coreopsis – plant breeders benefitting the plant dyer.
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?
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 “Anchusabracteolata, 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!
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.
Weld or Dyer’s Rocket (Reseda luteola) is a UK naturalised biennial wild flower that prefers to grow on chalk or limestone soil. It has pale yellow flowers and can grow to over two metres in height in its second year. The adult flowering plants are often seen growing in great masses on waste land or recently disturbed ground and may then mysteriously disappear only to pop up somewhere else another year. It has one common close relative, Wild Mignonette (Reseda lutea) which can also be used as a dye plant. Sweet Mignonette (Reseda odorata) is a closely related plant from the Mediterranean often grown in gardens for its attractive scent and as a bee attractant. All of these plants are well known for their perfume which is particularly noticeable when the plants are dried.
Weld is a Biennial
Two Weld rosettes in early spring
As a biennial, Weld is usually expected to grow from seed into a “rosette” in the first year. A rosette is a ground hugging form, where all the leaves grow from a central point. The plant goes through the winter as a rosette, when there may be some die back during cold frosty weather. In the Spring the rosette grows new leaves and the central stem starts to emerge into a tall flower spike. Once flowering is over the plant is expected to die. Well that’s the official line, but anyone who has grown biennials will know that it all depends on how the plants are grown (see photo).
Above, large Weld rosette in October it has tried to put out a flower stalk but the shortening day length has stimulated it to return to its rosette stage. Below, Weld in full flower.
Left to its own devices, weld seeds get scattered from mid-Summer onward. Some of these seeds will fall to the ground and germinate during late Summer and Autumn and grow into rosettes as expected. Other seeds will lie dormant in the soil and await an opportunity to germinate, usually afforded by a disturbance to the soil (animals rooting about for grubs or roots or a gardener tilling the soil). These seeds will take their chances to germinate at any time of year when the weather is warm enough. Some seeds will germinate in early Spring and, if the conditions are right, may complete their entire life cycle in one year. If the plants are stressed for any reason e.g. by drought or physical damage, they are even more likely to flower. The later in the season the seed germinates the more likely it is that it will flower in the following year. Weld’s rather random flowering behaviour makes it an awkward plant to cultivate. It is also highly sensitive to any kind of root damage, so transplanting seedlings invariably results in numerous casualties and transplanting an adult plant is almost impossible. It is quite often the case that the best plants the garden grows are those that have self-seeded in a path or on the vegetable patch – in fact anywhere except the bed you have set aside for growing Weld! It is not for nothing that Weld is generally regarded as a pioneer plant – one of the first to colonise waste ground.
Tiny round black seeds of Weld
The gardener interested in growing Weld for dyeing will seek to grow as large a plant as possible. This means allowing the rosette plants to build up good food reserves in their deep tap roots before shooting that ‘rocket’ of a flower spike up into the sky. This requires a certain amount of garden pampering and a choice of strategies.
The same bed about two months apart. On the left the weld seedlings have been planted for a week or two and the leaves have turned brown. Two months later many of the plants have died.
Sow seed thinly into modules in early April under glass or indoors. Do not cover seeds with compost as light helps them to germinate. When the plants have grown to around the five to ten leaf stage, carefully plant out into prepared beds in mid-May. Do not add any fertiliser to the soil as research shows dye yield falls with increased nitrogen, but do water as needed. Continue to water the young plants, particularly in hot weather, and weed throughout the year. With luck, some of the plants will grow large and flower in mid or late summer when they can be harvested.
Close up of struggling Weld seedlings
Sow seed thinly into modules in late August and plant out carefully when large enough and water regularly, particularly in hot dry conditions. Allow to grow and go through winter and they will flower in June/July the following year.
Self-seeded Weld with a few Dyer’s Coreopsis plants I planted in the gaps to brighten the bed up a bit.
Obtain some seed heads from wild Weld and scatter the seeds in great quantities directly onto prepared beds in spring. Keep beds watered and weeded. Scattering a few organic approved slug pellets will help to protect the young seedlings which may or may not germinate.
Mature flowering plants in the background and first year rosettes growing in the foreground.
Now if this all sounds a bit hit and miss, it is! When I grow the seeds under glass or indoors I certainly get excellent germination but lose many seedlings on planting out. Enough, however, survive to produce adult plants some of which I allow to set seed. If this is done over several years the seeds accumulate in the soil and self-seeding will start. Note: to stand any chance of self-seeding the soil must be kept bare i.e. free of weeds and any kind of mulch (mulch suppresses seed germination and harbours slugs and snails). Remember, Weld is a pioneer plant and does not like competing with vigorous perennial weeds. Small rosette plants can be moved from inconvenient positions if carefully dug out with a large clod of earth around the roots.
Weld does not make a particularly attractive garden plant in its rosette stage but if grown in ‘mono-culture’ it can put on a surprisingly good show when it flowers. If there are gaps in the first year Weld bed you can interplant other dye plants for added colour. Coreopsis is particularly good in this respect as it is an annual.
Mass planting of Weld
Right, dried Weld and Left, freshly harvested Weld being cut up ready for dye extraction.
Harvesting the plants just after they begin to flower in June is generally considered the best time. As the leaves begin to die off the amount of yellow dye starts to diminish, however, dyestuff can be obtained from the rosette leaves and from old plants that have finished flowering. All parts of the plant except the roots yield dye, including the stalks. Weld plants can be very big and take up a lot of storage space. If the plants are hung up to dry somewhere warm, dry and dark they will remain green, but if dried in the light they will turn a straw yellow or even bleached white. They will however still give good dye colour. Once dried the plant can be chopped up to save on storage space and kept in boxes, bags, storage jars etc. in a dry place.
Harvesting from the wild
Weld is often found growing on waste or disturbed ground, road verges and rail cuttings, so it is not that likely that anyone would complain about people picking it. However, the law is clear “it is illegal to uproot any wild plant without permission from the landowner or occupier. Uproot is defined as to dig up or otherwise remove the plant from the land on which it is growing, whether or not it actually has roots”. Occasionally we do harvest from the wild but we always try to be responsible by cutting the plant stalks (not pulling up the roots) and leaving plenty of plants to seed.