Battle of the Blues

Until 1856 when Sir Henry Perkins accidentally discovered a mauve-colored coal tar product, all dyes were from natural sources. Most (but not all) of these were plant based. Famous Tyrian purple was derived from a mollusk found in the eastern Mediterranean Sea. Interestingly, two cochineal scale insects were used as sources of red. One of these is native to Mexico and the other Southeast Asia. In 1900, a substitute for indigo was synthesized, ending the commercial use of natural dyes.

Indigo (Indigofera tinctoria) is a shrubby legume native to tropical Asia. It has been cultivated since at least 4000 B.C. It was used in ancient Egypt, Greece and Rome as well as throughout Asia. It was widely cultivated in India, hence the name.

Photo: Indigo for sale.

Recipes for extracting the dye vary from culture to culture. All involve a lengthy fermentation process. It takes 60 to 70 pounds of leaves to make two pounds of dye. During the late 1800s, the rush for Levi Strauss blue denim work pants led to demand outstripping the supply of indigo. In 1905, Adolf von Bayer of aspirin fame won a Nobel prize for creating a synthetic dye to replace indigo.

Indigo was not the only source of blue in the

ancient world. Woad (Isatis tinctoria) (right) a member of the cabbage family, was used as a dye since the Stone Age. The Romans reported that the Britons used woad-derived dye as warpaint, making them look more fierce.

Woad is biennial, meaning it produces leaves the first growing season,then flowers and produces seeds the second. Leaves for dye are harvested the first year. One ton of leaves produces less than five pounds of dye powder. Oil was extracted from the seeds to make soap.

By 800 AD, woad was an important crop in Germany and France. In the 12th century, Venetian merchants began importing indigo. Indigo's use was banned in England, France and Germany until the 1700s to

support the woad industry.

Photo: Hmong (Southeast Asian) girls wearing indigo-dyed clothes.

Relatively few dyes will directly bind with fibers. A second chemical called a mordant must be used to fix the dye. Plant- and animal-based fibers require different mordants. Tannic acid is used with plant fibers, and metallic oxides and salts with animal fibers. The choice of mordant influences the resulting color. I find it amazing that this process was refined to an art by folks ignorant of modern chemistry.

Should you want to try using garden-variety plants to dye fibers, fabric or even eggs, there are plenty of familiar plants that could work. For red, onion skins, beets, blueberries, carrots and red cabbage are readily available in the produce department.

Purple iris flowers are a source of blue. Rose hips make red. Surprisingly, peonies yield a pale lime green. For the novice, French marigolds and onion skins may be easiest to use. Extract the color by slowly bringing the material to a boil in water. Reduce the heat and simmer 30 to 45 minutes.

As crafts go, dying fibers requires a fair amount of research and trial-and-error efforts before one has a satisfactory result. On the other hand, using fruits and veggies to color eggs is an enjoyable activity for a rainy April afternoon.

You may want to visit the garden column archives to

review my article on coloring eggs with natural dyes which ran March 24, 2018.

Master gardener Ann Barton may be, like the rest of us, feeling a little "blue" these days with the coronavirus pandemic. Let's hope she can cheer herself up coloring eggs and puttering around the garden as we all wait for "indigo" away. Click on her pic at left to go directly to her Easter egg article.