A Brief History of Indigo Dye

Indigo is a historically significant dye that has been used for at least 5,000 years, and probably longer, by many cultures around the world. Manuscripts and tombs records contain examples of indigo. Indigo-dyed cloth has been found at archeological sites in Peru dating back 6,000 years, and with Egyptian mummies going back 5,000 years. Indigo was used in Guatemala, China, Japan and Africa. India domesticated indigo and has served as a significant indigo dye center. Indigo was an important commodity on the Silk Road, and traded as far away as Europe.

Historical indigo dye collection - photo by Shisha-Tom
Technical University of Dresden, Germany

In the 1700s, the Linnaeus Apostles collected information about indigo during their travels around the world, and Northern and Southern American plantations grew indigo for trade to the detriment of their enslaved workers. In the late 1800s, Levis Strauss famously produced sturdy work pants for miners from canvas sails and indigo dye; and German chemist Johann von Baeyer developed a synthetic indigo dye that has almost replaced natural indigo dye.

Indigo plant from which indigo is produced - photo by Saimon2000bd

Several plant species produce indigo dye. Indigofera tinctoria is called "true indigo", but other species such as I. arrecta and I. suffruticosa also produce indigo dye. The leaves contain the dye, which is invisible and attached to a glucose molecule. The leaves are gathered and soaked in water, where they go through a fermentation process. Soaking the leaves causes the glucose to split off. After soaking, you can remove the leaves because the indigo is in the water. You can dye directly in the vat, or drain the water and dry the extracted dye into cakes.

Indigo plant extract sample - photo by Bray Dunes

In its natural state, indigo is insoluble in water, and must go through this process where it is ‘reduced’ and put into a liquid state with the oxygen removed. In the ‘reduced’ state the indigo dye is a water soluble liquid and is a yellow green color. In this form the indigo is able to penetrate the fibers of the fabric. When the fabric is removed from the dye vat it is initially this same yellow green color, but begins to turn blue as the oxygen in the air reacts with the indigo. As the indigo oxidizes it becomes trapped within the fibers, making the dye permanent. 

Indigo dye examples - photo for Jacquard Indigo Tie Dye Kit
(Dharma Trading Co.)

Even though synthetic dye is widely used today, there is an ongoing effort to help farmers and dyers retain the knowledge and practice of growing and harvesting indigo, extracting the dye through fermentation, and using the dye to produce beautiful artisan and industrial-scale fabrics.

Learn More:

• Indigo Dye Kit Instruction Manual, by Jacquard Products. See the History section.
• Indigo: A World of Blue, documentary by Maiwa Productions.
• Indigo Workshop, by Michel Garcia. Natural Dye Workshop II, by Studio Galli.
• Indigo Dye, see the History section. Wikipedia.
• Indigo and Blue: A Marriage Made in Heaven, by Jenny Balfour-Paul. Textile Museum Journal 47 (January 2020): pages 160–85.
• Indigo: Egyptian Mummies to Blue Jeans, by Jenny Balfour-Paul. London: British Museum Press, 2016.
• Oldest Known Indigo Dye Found in Peru, podcast by Cynthia Graber. Scientific American, September 14, 2016.
• People Have Been Dyeing Fabric Indigo Blue for 6,000 Years, by Steph Yin. The New York Times, September 16, 2016.
• Textilia Linnaeana: Global 18th Century Textile Traditions & Trade, by Viveka Hansen, fifth volume in the Mundus Linnae Series, issued by the IK Foundation & Company (London 2017). Multiple references to indigo.

Bringing Back the Natives: 2023

The Bringing Back the Natives garden tour is back for 2023, with both virtual and in-person formats. Last weekend the virtual garden tours took place on Zoom, and in several weeks, the in-person garden tours will take place. As in previous years I attended both days of the virtual garden tours (but will be travelling during the in-person tours, so will miss see the gardens in person).

Doug Tallamy from University of Delaware gave the keynote address, “Restoring the little things that run the world: Why it matters, and what you can do”. Tallamy presented simple steps that each of us can­ take right in our own backyards to reverse declining biodiversity. Tallamy has written several books including The Nature of Oaks, and is a popular speaker on topics such as keystone plants, creating a wildlife corridor in the landscape, and starting a homegrown national park. His latest book is Nature's Best Hope: How You Can Save the World in Your Own Yard is a version of his previous publication Nature's Best Hope that is geared for middle-schoolers. Tallamy has inspired many gardeners to completely change the trajectory of their landscapes (and has deeply influenced our own upcoming landscape project).  

Interesting presentations include tours of landscapes with designers and property owners (some of  whom also embrace "green home" principles with solar panels, off grid electricity, and so forth); how to design and maintain monarch-friendly gardens; harvesting rainwater for irrigating your garden; and native plant sources in the Bay Area, such as East Bay Wilds and Native Here Nursery. I especially enjoyed learning about sunny and shady keystone plants (plants that are not only beautiful, but also support insect and bird life); native plants as street trees (progress is being made in some cities); and the important role that aphids play in the landscape (hint: they are the basis of the food chain, so embrace them). For the soul, I loved the photo-essay "Life and Death on Silverleaf Lupine" and the video "The Beauty of New Life: March and April in the Native Plant Garden".

Upscale bird bath

Resin bird bath and fountain

Neighborhood lending library with succulent roof

It's not too late to sign up for the 2023 in-person garden tours on Saturday, May 6 (Bayside gardens) and Sunday, May 7 (Inland gardens).  Registration enables you to visit the gardens and see the recordings from the virtual garden tours. To learn more about the online agenda from last weekend, see Agenda 2023 Online Tour. To learn more about the in-person agenda in a few weeks, see View 2023 In-Person Tour Gardens. The tours are free, but donations are appreciated to offset costs.

Birthday Flowers: Sweet Peas

 The birth flowers for the month of April are sweet peas and daisies. Their delicate and cheerful flowers are perfect for celebrating spring and any baby born into the fourth month of the year. Sweet pea bloom colors include rose, red, maroon, pink, white, yellow, purple or blue and some are bicolored. They also grown for their fragrance, which can change depending on the time of day and weather,

April - Sweet Peas

As with all other flowers, colors have meaning:

• White - peace, purity, and innocence
• Pink - happiness and non-romantic love
• Red - passion, love and romance
• Purple - royalty, pride and success
• Blue - rarity, uniqueness, desire, and calmness

Sweet peas (Lathyrus spp.) are included in a genus of flowering plants in the legume family Fabaceae that contains about 160 species. Favorites for giving include L. odoratus, L. latifolius, L. sativus, and L. vernus. Lathyrus vestitus is native to western North America, and found in the forests, woodlands and chaparral of California. Subspecies can be found extending into Oregon and Baja California. Enjoy these delicate beauties, but keep in mind that the flowers and plants can be toxic to humans, cats, dogs, and horses.

An Atmospheric River Runs Through It

 We recently experienced our twelfth atmospheric river of the season here in the San Francisco Bay Area. It blasted through in a fury of rain and high winds, leaving mud slides, flooding, power outages and downed trees in its wake. Down the street, one of the big pine trees toppled over and blocked the road for a day. We lost power for two days and internet for close to two weeks, and our oak tree dropped one of its smaller branches.

What is an atmospheric river anyway? I didn't even know they existed, and suddenly they are a common occurrence. According to the National Oceanic and Atmospheric Administration (NOAA), the term describes a long narrow region in the atmosphere--like rivers in the sky--that transport most of the water outside the tropics. The columns of vapor move with the weather, carrying an amount of water vapor equivalent to the average flow of water at the mouth of the Mississippi River (the columns can be 250-375 miles wide). When the atmospheric river reaches landfall, it releases the water vapor in the form of rain or snow.

Of course, we're all grateful for the rain, but after six months of it, it's time for another season! Still, it is interesting to read that scientists are recommending that we harvest surplus rainwater to replenish the aquifer. Much of our infrastructure here in California is all about draining water to prevent flooding. Maybe it's time to rethink that and capture the water instead. Is there a way to redirect atmospheric rivers to spread the water around? Perhaps our chronic drought situation here in the West could be eased with some creative ideas and actions. In the meantime, I'm relishing some dry and sunny days!