Indigo blue - growing, harvesting, processing and marketing indigo dye plants

putting this here to read later...a great article about them titled " the future of fashion is farm to closet" was in the June National Geographic.

https://www.sukkhacitta.com/blogs/craft/sweetindigo

all 13 links here now...

Judith Browning wrote:here are links to
© Catharine Ellis, as posted to the blog: Natural Dye: Experiments and Results

"On this blog site, I have previously written about the indigo fermentation vats in very general terms. I have been using these fermentation vats exclusively for over 5 years now and I feel strongly that it is the best approach to use for indigo dyeing. So, I have made the decision that I would like to share much more specific information regarding how to make and maintain these vats through a series of posts in coming weeks. I hope to roll a new one out every few days days or so. "

https://blog.ellistextiles.com/2025/05/03/fermented-indigo-vat-1-a-journey-from-quick-reduction-to-slow-fermentation/

https://blog.ellistextiles.com/2025/05/06/fermented-indigo-vat-blog-post-2-fermented-indigo-vats-vs-quick-reduction-vats-vs-chemical-vats/

https://blog.ellistextiles.com/2025/05/09/fermented-indigo-vat-blog-post-3-what-is-indigo-reduction-explained-to-the-best-of-my-ability/

https://blog.ellistextiles.com/2025/05/10/fermented-indigo-vat-blog-post-4-how-does-fermentation-reduce-an-indigo-vat/

https://blog.ellistextiles.com/2025/05/20/fermented-indigo-vat-blog-post-5-getting-started-with-the-fermentation-vat-and-things-to-consider-before-making-a-vat/

https://blog.ellistextiles.com/2025/05/23/fermented-indigo-vat-blog-post-6-recipe-basic-fermentation-vat-with-soda-ash-or-potash/

https://blog.ellistextiles.com/2025/05/27/some-more-thoughts-about-indigo-fermentation-blog-post-7-what-i-have-learned-from-a-biochemist/

https://blog.ellistextiles.com/2025/06/02/fermented-indigo-vat-blog-post-8-recipe-basic-fermentation-vat-using-wood-ash-lye/

https://blog.ellistextiles.com/2025/06/07/fermented-indigo-vat-blog-post-9-dyeing/

https://blog.ellistextiles.com/2025/06/24/fermented-indigo-vat-blog-post-10-vat-maintenance-long-term/  

https://blog.ellistextiles.com/2025/07/01/fermented-indigo-vat-post-11-problem-solving-and-other-practical-stuff/  

https://blog.ellistextiles.com/2025/07/04/fermented-indigo-vat-blog-post-12-some-further-thoughts-on-the-amount-of-indigo-to-be-used-in-a-fermented-vat/

https://blog.ellistextiles.com/2025/07/06/fermented-indigo-vat-blog-post-13-a-wrap-up/

Thanks for the links about indigo vat. I am going to try that one day but right now I am still stumbling with the basics. In the recent trial, I soaked 2 oz leaves for two days till them broke down to release pigments. I then strained and filtered the extract to remove solids and added some soda to increase pH. The solution was ready for dyeing with cotton fabric as is. I then added calcium to precipitate and concentrate the pigments. Retesting the colors showed both improvement and limitation for this procedure. I am going to try a different method next time with sun-dried leaves for a darker color.

May, I love seeing your projects!

and your record keeping is amazing...seems like there might be a dye book in your future?

I’ve been experiementing with pigment extraction using anil (Indigofera suffruticosa) that I’ve been foraging from disturbed areas here on the central gulf coast of Florida. I’ve used your blog post extensively throughout my experimentations as it has been the most detailed and thourough in explanation. I just wanted to share for any other people that might read this who are curiously beginning their own indigo adventures, that the acidic hot water extraction works extremely well. And that despite all of the forums, sites, videos, articles, etc. online that say fermentation of the leaves takes anywhere from a day to 5 days, be aware this relied heavily on the temperature of where you are. I’ve had a completed extraction happen in as little as 1-2hours with the steeped leaves starting in cool water and with no acidifying agent and set in the midday Florida sun. So if it were me, I would check my fermenting solutions quite often the first few times but also the hot water method is wayyyyyyy faster and easier to control in my opinion and experience! Cheers

Thanks for sharing your tips. It's great it works for you so easily. Do you use for straight dyeing or something else? Welcome to share your projects!

Temperature does make a big difference for me. If I leave it too long or it gets too warm, the leaves rot and the pigments dissappear. The simplest way for me so far with Japanese indigo is to use young leaves. I pluck the top two leaves and submerge them in water. The cell walls are not fully developed and so permeable that I get turquoise solution and flakes of insoluble indigo floating on top. I am encouraging my plants to get bushier, similar to growing tea and harvesting the leaves.

beautiful color May!

Indigo plants dye protein and cellulose fibers quite differently. It's much easier to work with wool yarn or silk fabric since they have more functional groups for strong interaction. I tried putting leaves in blender for direct dyeing. It gave a vivid teal color for Al mordanted silk fabric in a acid bath and the whole process took less than an hour. I couldn't do the same with cotton or linen (adjust to high pH)  due to interference from the chlorophyll.

Anyway here are a linen napkin dyed with freshly leached indigo and a piece of silk noil with regular alum mordant and acid bath.  Different blue hues but equally beautiful.

I come up with a different way to extract pigments from mature leaves, instead of getting dyes in the reduced form in a solution and oxidize externally, I induce the leaves to produce indigo internally. The leaves can be dried, fermented or extracted. I am gathering the indigo paste in a jar until I get enough for bigger projects. With this concentrated paste now I can obtain much darker color.

My indigo patch is blooming so I cut half down and extract dye the traditional way. It took three days of soaking and one day for extraction. The indigo paste can be dried for storage or used for dyeing process.