Purging Buckthorn (Rhamnus catharticus) is a woodland edge species that grows in limestone areas. In the Yorkshire Dales there are only a handful of mature shrubs and they are not good at natural regeneration. Thus, a few years ago, a small group decided to engage on a propagation project.
“Germination was hugely successful and we now have hundreds of plants of varying ages to plant out over the next two years and increase the biodiversity of this area” writes Melanie Fryer – a member of the group and an active member of FoodFutures sustainable food network in North Lancashire.
“Purging Buckthorn is the larval food plant for the beautiful Brimstone butterfly. It is also an amazing shrub for natural dyes”.
Sewing Cafe Lancaster’s (SCL) Natural dyes group has a living collection of plants at Claver Hill, and recently extracted the seed from this year’s purging buckthorn crop (shared by Melanie) and used the pulp and skins to create a dye.
“It turned out to be a most intriguing dye” commented Katrina, a member of Sewing Cafe Lancaster.
“Firstly the extracted liquid and pulp from the berries appeared a very deep purple and it was exciting to see such a vivid green appear on the wool samples and the silk turning to a dusty gold colour. The cottons showed the greatest range of shades from deep blue/grey through to pale green/yellow, depending on the strength of the dye bath. Although some lovely shades were produced, there was no hint of the bright yellow SCL hoped for”.
“Purging Buckthorn requires alkaline conditions to thrive, so it seemed possible that different results might be achieved in the dye bath if bicarbonate of soda were added to increase the alkalinity. A quick experiment confirmed this and the dye bath was adjusted resulting in a bright yellow being produced on cotton and wool”.