Sunday, 27 July 2008

Polygonum Tinctoria

A week or so ago I used the leaves of one of my dyers knotweed (Polygonum tinctoria) to get that most elusive of colours for natural dyer -turquoise. I principally followed the method that I found on the net as below :
I picked the leaves of the one plant that has grown indoors , which weighed 96g.
I rinsed them
Put them to drain
Then chopped up the leaves with a pair of scissors. It was then I realised that my hands were going turquoise , a very good sign I thought. I found a reference to this technique in Dominque Cardon's book Natural Dyes and she said to add 0.7litres to 50 g of leaves. So I added 1.3litres and then kneaded the leaves with the water going green . I added 125ml of 10% acetic acid ( in proportion to 50ml of 25% acetic acid /20 litres) .
I strained the liquour off and then ran into difficulties not quite understanding the instructions but kneaded the leaves again with added vineagr. I am not quite sure if this was right prehaps I should have jsut kneaded the leaves in the original dyebath I am not sure here.
At this point my dyebath should have gone much darker but it did not. I put my pieces of silk in anyway and went off to have a cup of tea. Whne I returned half an hour later the silk was turquoise. Hooray! I put it back in three or four times and it slowly went darker,
Today I tried again with a magnificant 1.2 Kilos of leaves from Enys' greenhouse but I have got a pale green rather than a turquoise and not very much of that. :( I think that in retrospect I did not knead the leaves enough. I will try again soon! As soon as I have enough leaves that is.


  1. My polygonums look also ready for harvest, but I am still gathering courage to do something with them.
    I am glad to see it worked for you:)
    Maybe I should try with a small amount first, too. Do you think that vinegar-thing would work with wool also, (I don't have silk)? Or maybe I'll just do it with hydrosulfit. This is so new to me.

  2. Hi Leena I just tried it again to day as I found a bag that Enys had brought I had missed. This time I got quite a deep green but it does seem to turn turquoise slowly. I have no idea what the chemsistry of this is! This time I got a good colour I did not even use any vinegar as Jenny Balfour Paul does it without. The trick is to chop the leaves very very finely . I do it with a pair of scissor and keep on chopping. Then knead the leaves It si odd though -quite unnerving as it seems quite contrary to the way to dye with indio. And yes wool does work too although the colour seems a little paler.

  3. Helen, my plants are growing too - I'll have to make time in a few days I guess! but Dorothea said that by now she found out that you can use the leaves at any stage, doesn't matter if the plant already flowers or not. and yes, it does work on wool, but as you said, the colours stay paler. the vinegar doesn't damage the wool either. I was thinking of using one of those double-blade herb choppers (looks like a half circle with two handles) on a plastic board to chop the leaves very finely... I think the second kneading is done to try to release as much pigment as possible!

  4. Bettina I found a pair of kitchen scissors and chopping a handful at at a time worked very well, but wear gloves as my hand and nails went turquoise! I think the second kneading may well release more dye so I supect that rather like making bread the success of this technique is in the kneading!
    I am interested Dorothy said she got colour form all stages even including post flowering. There is always more to learn!

  5. I just popped here to see if you had said how long you kneaded the leaves? Right now I have yarn in green liquid made from jp, and I am having doubts if I should have kneaded them longer, i didn't have a watch with me outside, but I did it maybe 5-10minutes both times, second time a little shorter. This is so exciting!! I will have pictures in the computer tomorrow, and then the yarn should also be final color.

  6. Lovely! If I ever get to have a garden again, I definitely want some of this!

  7. Hi Leena 5-10 minute seems about right to me. I did it till the water did not go any darker. You need to leaves the yarn in for about an hour. LIft it out and air it and put it back . Carry on doing this till it does not go darker. I am findng this one very exciting. The ladies who came round the garden kept on saying "it's alchemy" by which I think they meant a kind of magical science!