Saturday, 25 July 2009

Weld: Dye from Leaves, Seeds, or Stalks?

Posted by Helen
First Year Florette
Mature Weld

Where is the dye in weld ( Reseda Luteola) ?
Recently I have seen a comment that most of the dye is concentrated in the seeds, (Judy Hardman, Natural Dyes) . (I reviewed her new book a few weeks ago and you can find that here) Dominique Cardon says that the dye is mostly in the seeds,inflorescence's and leaves, although traditionally the whole plant was always used which makes it bulky to store. Sue Grierson reports a 19th century source (Rhind) saying that the thick hollow stems of weld have little dye in them and to use the thin stalks (along with the rest of the plant).
According to Cardon the dyes in weld are flavones: luteolin and apigenin although mostly the former. It is luteolin that gives the strong light fast yellow that makes and made weld such an important dye plant. Grierson describes the colour as primary yellow but that she sometimes had to add soda to achieve this colour (by which I assume she means sodium carbonate or washing soda). Cardon reports that the yields of dye from weld vary enormously and puts this down to different strains, but I wonder whether it is also due to harvesting times as harvest weld too soon and the colour can be poor whereas it seems to go on giving colour till the leaves are withered . Once the leaves are gone in my experience there is no colour.
My friend Debbie Bamford has written an informative blog about weld with a picture of a magnificent specimen growing outside one of the outbuildings. You can find that here

On Friday 24th July I cut all the weld in the garden during a rare period of sunshine following very heavy rain in the previous few days.I mention this as Dominique Cardon says that the yield is improved after moderate watering although I am not sure our cloud burst could be described as moderate! Most of it has gone to be dried some for my own use some for sale but one stand I kept for an experiment.
When I cut the weld ,the bottom leaves were starting to go yellow and most of the inflorescence's had gone to seed which is when I judge weld to be at it's best. The seed comes from weld that grows wild locally -on areas of disturbed ground in the village where I live in North Wales weld has grown wild for many years. After I ran my first dyeing workshop here in 1995, the sister of one of my students, a lady well into her 70's, came to tell me that she used to pick weld to take to the teacher in the school in the village for all the pupils to dye with and showed me where to find it . Near this site Ladies Bedstraw ( Gallium Varum) grows wild too. Since then I have often found weld particularly on some rough ground later used for building. Ever since I first brought back weld it has grown in my garden sometimes more sometimes less. This year I have had four stands of self sown weld.
So while DH and I enjoyed a glass of wine in the early evening sunshine we split one stand of weld. The inflorescence's /flower heads and seeds into one pot. Leaves into another and stalks into a third. The stalks were quite fine less than 5 mm wide with the thickness of the wall about 1mm
Seeds/flower heads: 137.7g +3 litres
Leaves: 116g+2.5litres
and were soaked overnight
There was no discernible colour in the water after soaking overnight
Pots were put onto to heat at 10.39 and by 11.55 were:
stalks 90 degrees C
Seeds 60 degrees C
Leaves 60 degrees C
The colour of the dye liqour in the pots was a pale yellowy green and seemed to be the same.
I turned up the heat under the seeds and leaves and by 14.30 they were:
Stalks 90degrees C
Seed heads 85 degrees C
Leaves 85 degree C
Then I turned the heat off and left overnight.
The stalk bath had the characteristic weld smell.

There are a variety of ways to dye with weld. Cardon reports two methods used by French silk dyers. In one the weld was covered with cold water and heated for 15 minutes this was extracted before the process was repeated and the two extracts put together. In the other weld was covered with cold water and boiled for an hour.In both cases the plants were removed from the water. As you can see from my notes above I leave the plant materials in after heating and will also leave them in while dyeing but this is partly because I am not concerned with even dyeing as I shall be dyeing Wensleydale fleece. I have also,in the past, left weld soaking for several weeks when it fermented and gave quite an astonishing amount of colour.

I then checked Partridge who is a great fan of weld and he says to dye wool a fine yellow put wool previously mordanted in alum to boil for quarter of an hour and then let it lie all night . He adds pearlash ( wood ash lye-potassium carbonate which Liles says can be substituted by sodium carbonate).and tin to get a bright yellow.

10.08am Sunday 26th September
Added 2 litres of water to each dye bath
190gof wet mordanted (8% alum 7% Cream of tartar),Wensleydale to each dye bath -all I had. The dry weight was probably half that so I am using at a rough approximation 100% dye stuff to fibre.
The fibres in the seed head bath took on pale soft lemony yellow immediately. Fibres in the stalks and leaves bath look unchanged.
Started to heat.
Stalks 97 degrees soft yellow
Seed heads 72 degrees bright yellow-this is the strongest dye bath
Leaves 65 degrees soft yellow-this is the weakest bath
by 1 pm the difference in colour is very noticeable. The seed heads are in the lead with a bright yellow, the stalks follow on behind with a softer yellow but the leaves trail in third place the colour being softer and not as bright.

I browsed through my old dye books to see how different people dyed with weld. Something I should have done before I started not afterwards! Jill Goodwin in "The Dyers Manual" -the first dye book I ever brought- mentions both chalk and salt. Many Dyers of old she says used chalk and others salt. I have tried chalk-don't think it made any difference but not salt. Although it might be too late I removed a sample of fibres from each bath and added 1 teaspoon of salt to each bath now with the heat switched off.Colours of the dye bath

Samples from each dye bath with ammonia added on the bottom row.
Leaves on the left, seed heads in the middle, and stalks on the right. Once ammonia was added the difference between the dye bath was not very obvious. Salt added made no discernible difference samples second row. It should have been added in the beginning.

My conclusion is that there is more dye in the seed heads then anywhere else but still enough from all the other plants to make gathering the whole plant advisable unless you are very short of space.
Welcome to new followers. Your presence is appreciated.

Books I have referred to in the text are:
William Partridge A Practical Treatise on Dying published by Pasold Research Fund Ltd
Jill Goodwin A Dyers Manual Published by Ashmans Publication ISBN - 9780954440107

Liles, J N Art and Craft of Natural Dyeing The University of Tennessee Press

Sue Grierson The Colour Cauldron Published by the Author ISBN 0 9510132 11
Judy Hardman and Sally Pinhey Natural Dyes Published by Crowood ISBN 978-1-84797-100-5
John and Margaret Cannon Dye Plants and Dyeing Published in association with the Royal Botanic Gardens Kew ISBN 1-871569-74-5
Dominique Cardon Natural Dyes Published by Archetype Publications ISBN -1-904982-00-5


  1. Very interesting, Helen! I harvested about half my weld last week, as I was trying to clear up a bit for the RedCross open gardens day last Sunday. Up here at 270m above sea level the weld hasn't quite finished flowering so I shall leave the rest for a bit longer (I usually leave some for seed anyway.)

  2. Hi Helen
    this is very interesting. I've got some weld, harvested this year, now dried, which I've to use in a dye pot. My past efforts produced beautiful clear and bright results, so am quite looking forward to using it. I'm not going to separate the seeds, stalks or leaves, but use the whole lot. I haven't quite got the stamina to separate!

    Good luck at Summer School.


  3. Hi Alison I have been drying some of mine and seed is cascading onto the newspaper below.
    Hi Alison - I don't think you have to bother separating them as all of parts gave some dye but I was intrigued to find that the leaves gave the least.
    Thanks for the good wishes about summer school at the moment I am at the stage of thinking "I must have been mad to agree to do it"!

  4. Thanks for making such a detailed posting about weld. This is my first year growing and dyeing with weld; I've been happily surprised at how large the plants are! I harvested and dried quite a bit of the plant stems and leaves about six weeks ago. Using it recently, I obtained pale, wheaten-color yellow...lovely,but not very bright. I've been letting the rest of the (very large) plant go to seed, so was excited to read your post that the plant in seed gives the best yellows! (I was thinking it was too late to get any more dye from it). I'll be boiling some up and adding ammonia, like you did; I'll see what happens! Thanks again for taking the time to post your experiment.

  5. I am so glad that you find the weld article useful. You probably cut your weld too early from the sound of it. I hope you geta better colour when it has gone to seed. I see you like fermented foods-well fermenting dyes brings up interesting colours too. :)

  6. Thanks for writing about your careful experiment. I have no weld plants this year, but will be planting seed in the autumn,I didn't dye with the plants I grew before but did manage to keep seeds, and now I am greatly encouraged to grow the plants and harvest them and dye!

    By the way, a neighbour who is a keen gardener (& not a dyer) was jaw-droppingly impressed when she saw the weld in flower last year.

  7. Hi Dorothy I still plan to see whether the thick stems on weld are poor in dye as they are reported to be so still some experiments to do! I had Jackie Crook, who wrote a lovely dye book published by Gaia in my class at Summmer School and she reckoned that the thick stems did not hold much dye.