PLANT OF THE MONTH: Woad

Latin name:  Isatis tinctoria 

Ecology and habitat

Woad thrives in temperate climates preferring well-drained soils. It is relatively tolerant of poor soil conditions and drought, which has contributed to its widespread cultivation historically. It can be found in various locations such as fields, roadsides, and brownfield sites.

It is a biennial plant, meaning it completes its lifecycle in two years. In the first year, woad grows a rosette of leaves close to the ground. These leaves are pivotal for dye extraction. In the second year, the plant produces tall flowering stems with small yellow flowers that smell lovely and are used by many pollinators.  

Uses of woad

Renowned for its deep blue dye, woad has played a vital role in the the UK’s textile industry and agriculture. 

• Dye and soap production 

The most famous use of woad is its dye, which has been a staple in the textile industries of the UK for centuries.

The dye is extracted from the leaves of the plant through a complex process that involves fermenting, drying, and powdering the leaves before they can be used for colouring fabrics. On a commercial scale, one acre of land produces about ten tonnes of leaves twice a year. One tonne of leaves produces just two kilos of woad powder. 

Woad dye produces a rich blue colour via the chemical Indigotin, which is identical to the blue dye chemical in indigo. The black seeds  of woad are winged, resembling small tongues, and can produce an olive dye and also woad oil which is used in soap. 

• Historical and Cultural Significance 

Woad holds a significant place in British history and culture. The earliest evidence so far found of the use of Woad in the UK dates from the Iron age (1st century BC from an excavation in Humberside).

Ancient Britons used woad dye not only for textiles but also for body paint. Woad has a long association with East Anglia, the land of the Iceni tribe and of their leader Boudicca. Woad is a well-known antiseptic and it may have been used to help heal battle wounds. 

The illustrators of the Lindisfarne Gospels (late 7th/early 8th century) used a woad-based pigment for the blue. Amongst pagan users, woad is was supposed to aid in shape-shifting and the study of past lives during magic rituals. 

• Medicinal Uses 

Woad was also used widely in traditional medicine. The plant's leaves contain anti-inflammatory and antibacterial compounds making at a versatile home remedy. Woad root granules are used in Chinese medicine for treatment of cold and throat infections.

• Modern Applications 

Today, woad is experiencing a renaissance as interest in natural dyes grows (for example in our current dye bed at Rosamund Garden). Sustainable fashion brands and artisans are rediscovering woad for its eco-friendly dyeing properties. Its cultivation is also being explored in regenerative agriculture practices, where its robust growth can aid in soil restoration and biodiversity enhancement.