For an account of the first day of this workshop, see Plant dyes with Nature’s Rainbow part 1.
On day 2 we turned to red, looking at madder. Madder is very invasive, so Susan advised growing it in an enclosed area, like a tractor tyre. It also takes around three years before you can start harvesting the root, where the colour resides, and then after digging it up, washing it, drying it and snapping it into pieces she leaves it for another year in paper bags.
The root contains around over 15 different pigments, ranging from yellow and orange to coral, scarlet and brown. Some of these pigments emerge more quickly than others – for example, yellow and coral come out first, but alizarin, which gives the red colour, is not very soluble and is the last to emerge.

For this reason, despite traditional instructions that say madder should not be heated above 60°C, Susan and Ashley have found that working the bath quite hard for at least a week, cooling it and reheating it, produces the best reds. You can also add an alkali modifier to shift the colour from orange towards red.
For the workshop we compared two madder recipes, one from Jim Liles’ The Art and Craft of Natural Dyeing and the other from Ethel Mairet, the author of a seminal book on vegetable dyes written in 1916.
The Liles recipe involves over three days of heating and straining to extract the best red pigments from the madder. The Ethel Mairet recipe by contrast is a very low effort method where the dye is extracted in the dyebath (no preparation required). They gave very different results.
Ashley and Susan had prepared the Liles method in advance and brought a madder dyebath which combined three days of extract. The Ethel Mairet bath was created by adding dry madder root to the dyebath (contained in an old paid of tights to prevent pieces getting caught in the wool and silk fibre).
In both recipes the wool was added to the dyebath at room temperature and heated to 82°C (simmering temperature) for 1.5 hours (Liles) or 1 hour (Mairet). Liles then instructed us to remove the wool, cool it and rinse it before putting it back in the bath at 70°C for 10-15 minutes. Then it was drained, cooled and gently rinsed. By contrast, after simmering the wool for an hour Mairet recommended boiling for the final five minutes before removing the wool, cooling it and rinsing.
In both dyebaths we resisted the temptation to agitate the fibre lest we felt it. We carefully turned the fibre over once in the Mairet bath.
We also used a dyebath created by vigorous boiling of the madder root left over after 3 days of the Liles madder extraction process. Ashley called this his surprise “4th extract”.
The results were interesting. The Liles recipe, extracted over days 1-3, gave the strongest colour (seen in the two samples on the right), followed by the Liles fourth extraction (sample bottom left). The Mairet recipe resulted in a very patchy sample that was much paler (top left).

Meanwhile, on the other side of the room, overdyeing with indigo some of the yellow samples dyed the previous day continued, and soon there was a splendid range of greens hanging outside.
The buttery mid yellows gave the brightest greens when overdyed; more orangey yellows gave a more olive green.
Ashley also demonstrated how multiple dips in woad helped get a deeper colour. The wool on the left has been dipped in woad five times while the wool on the right has been dipped only once.
Susan showed us a sample card of how acid and alkali modifiers after dyeing can change the colour, depending on the fibre and the mordant.
Unfortunately we didn’t have time to overdye the madder samples with indigo to see if we could get purple shades, but we had quite a lot to take home already! We spent the last hour of the workshop splitting up all the samples so that everyone had a good collection to take home.
Suan and Ashley were very generous, offering us more weld, madder roots and all the leftover dye baths to take home. Many of us also bought seeds to start our own dye gardens!
There was just time to take a final photo of the beautiful rainbow of samples before heading back out into a grey January evening.

And here is the collection of plant-dyed wool and silk that I ended up with.
Huge thanks to Sally for her organisation and to Susan, Ashley and Brian for such a wonderful colourful weekend!