Rhubarb Root (Rheum rhabarbarum)

Rhubarb (Rheum rhabarbarum) is a familiar perennial garden plant, recognised for its large green leaves and thick red or green stalks which grow in spring and summer. While the stalks are widely used in cooking, the roots have a long history in natural dyeing and can be harvested from mature plants at any time of year, making good use of material that might otherwise be discarded.

West Yorkshire is famous for the Rhubarb Triangle, an area between Leeds and Wakefield, where forced rhubarb has been grown commercially since the nineteenth century. Although this tradition is centred on producing tender pink stems for eating, the roots from mature plants have also been valued for their natural dyeing properties.

Rhubarb roots contain natural yellow pigments and tannins that produce warm dye colours. When simmered they typically yield shades ranging from soft buttery yellow to rich golden ochre, depending on the age of the root and the amount of plant material used.

Because rhubarb root is naturally rich in tannins, it helps the colour bond well to fibres, particularly cotton and linen. Alum generally produces golden yellows and oranges, while iron deepens the colour to olive, khaki, or warm brown tones.

Rhubarb root dyes work well on both wool and silk, producing rich, long-lasting colours, and are also effective on cellulose fibres such as cotton and linen. As harvesting the root usually involves dividing an established plant, it is best carried out sparingly and only when routine garden maintenance is already taking place.

Images show tests using silk, cotton, linen and wool samples.
Samples were tested with no mordant, alum mordant and iron mordants as well as using a soda ash modifier after dyeing