Woad – The mysterious blue vegetable dye

The wood is famous for being the source of the blue dye that has been used to dye wool and other fibers for several thousand years in Europe and the Middle East. The pigment is extracted from the dark blue-green, spinach-like leaves of woad.

the wooden plant

Woad (Isatis tinctoria) is native to the Mediterranean and belongs to the cruciferous family, more commonly known as brassicas, and is closely related to broccoli, cabbage, and rapeseed. The wood grows easily and is considered a noxious weed in some US states.

Wood is a biennial plant and grows for two years before dying. In the first year, it forms a low-growing cluster of leaves like spinach. The leaves are harvested for dye production only in the first year, because they have little or no color by the time they reach the second year.

In the second year, the leaves become longer and thinner and the mint plant looks quite different. It produces tall stems up to five or six feet tall with clusters of small, neon yellow flowers. The flowers, which appear in May, have a wonderful fragrance and attract many bees. The black seeds that follow are winged, resembling little tongues and after producing seeds, the plant dies.

wooden blues

Dyeing with woad is very exciting. The wool or cloth is immersed in the vat, left for a few minutes, and then removed. At first, the wool is pale yellow, but with exposure to air, the color gradually turns green, and then blue. This color change never fails to fascinate onlookers.

Wood is also very cheap; 10 grams of woad pigment, for example, will dye more than 200 grams of wool a beautiful medium blue, and at least another 100 grams of wool a light blue.

Traditionally, a fermentation vat was used to tint with cake, often starting with rancid urine. Fermentation removes oxygen from the vat making the cake a soluble pigment. Today, chemicals such as spectralite are often used to remove oxygen from the vat.

Wood and the ancient Britons

Woad is native to the Mediterranean, native to Turkey and the Middle East, from where it spread to Europe and has been used as a dye plant since Neolithic times, between 5 and 10,000 years ago.

Many people have heard that when Julius Caesar’s army invaded Britain in 55 B.C. C., the Romans saw the Picts painted blue with pastel. There is a great deal of controversy regarding this statement, as it is unlikely that the Roman army, which was mainly in the south, ever encountered any Picts living in the north of Scotland. Also, pastel is difficult to use as body paint and is not suitable for tattoos.

Woad as an anticancer agent

It’s not just a blue dye that can be extracted from grass; peppermint has also become a weapon in the fight against breast cancer. Recent research has found that broccoli has 20 times more of the cancer-fighting chemical glucobrassicin than broccoli. It’s difficult to extract the chemical from broccoli, so the cake provides an effective alternative. The wood can produce even more of this chemical if the young leaves are damaged. However, do not try to eat cake as this plant is inedible.

using wood

Have you heard the song of wood? The last stanza goes like this;

March on Snowdon with your grass on,

It doesn’t matter if it rains or snows

You never want a button sewn on.

Forward, old Brits!

There is enough information available on the internet today to enable you to grow your own grass, extract the blue pigment, dye some local wool and knit a blue scarf to wear the next time you climb Snowdon (or the local mountain peak)! !