Indigo Harvest in Okinawa

A life of natural dyeing knows no bounds. Each year I am thrilled and delighted to increase my knowledge and understanding of dyes and process. 

This year, I was privileged to participate in the harvesting of indigo and the extraction of pigment on the island of Okinawa, Japan. 

The Okinawa farm has been producing indigo for many years, as evidenced by the large, round concert vessels imbedded in the ground. The vessels are used for extraction of pigment.  Smaller square vessels, also in the ground, are used for the storage of the indigo paste pigment. 

The indigo harvest and extraction is currently being done by a young couple, Takashi and Kitta Sawano. They have been extracting pigment here since 2012.  He is a dyer. She designs and makes beautiful, naturally dyed cotton garments in a studio located in northern Okinawa. The process of harvest and extraction requires many helping hands and there were a number of friends and artisans  who came to get their hands dirty and participate. 

The variety of indigo is Strobilanthes cusia. It looks similar to polygonum tinctorium but this variety requires a hotter climate and has a greater content of indigotin. Even the stems of the plants contain indigo. Eight different harvests are made during the summer season to extract pigment from all the indigo plants.

It was pouring rain the morning we arrived to harvest. I was given a small scythe and some white ropes. I felt somewhat prepared for the cutting and tying process since this is  the same approach that we used last summer when harvesting Polygonum tinctorium at Rowland Ricketts studio/farm. Everything else about the process was different, since Rowland uses his indigo to compost the leaves for sukumo.

The goal was to collect 400 kilos of indigo plant (leaves and stems). Each bundle was weighed and the weight of the wet leaves was taken into consideration. The plants were then tossed into one of the large round vessels that was already filled with water. A porous round tarp had been placed over the surface and the plants went on top of that. The indigo plants were weighted down with wire mesh, boards and rocks to ensure full immersion.  The plants were left to soak for the next 24 hours. 

On the next day, we observed that some fermentation was beginning and measured the pH. 

On the the third day, the fermentation was very active. The plant material was lifted out of the vessel (with the help of a small tractor).  Lime was added. The amount of lime was carefully calculated as too much lime will result in an inferior pigment.  The indigo extraction was aerated for 45 minutes using long rods with a small paddle affixed to the end. The shape of the vessel made this a very efficient operation.



The introduction of oxygen through aeration caused the indigo pigment to precipitate to the bottom of the vessel. Once the excess water was pumped off the surface, the paste pigment could be pumped into a storage container, where a more concentrated pigment will settle to the bottom over the next few weeks. 

I purchase  indigo for use in my own dye vats. Most of it has come from India but I am currently using indigo grown right here in the U.S. at Stoney Creek Colors.  This experience has given me a new appreciation and understanding of the cycle “grow, extract, dye” and a deep respect for those who participate in the entire process.  My thanks go to Hisako SUMI, who has participated in this indigo harvest for the last number of years and invited me to attend –  in the spirit of understanding and sharing. 


24 thoughts on “Indigo Harvest in Okinawa

  1. Hello!

    Thank you so much for the wonderful photos and explanations. I was just wondering how to determine how much lime to use. I am growing persicaria tinctoria in small amounts and hopefully will soon start extracting.

    Another question- how is the quality of the indigo from the USA?

    thanks again for your blog- it is truely helpful.

    Best wishes,

    1. Since I do not typically extract pigment, I did not pay close attention to the amount of lime added. It is my understanding that the less lime the better. Excess lime will bind with the pigment and render less pigment available for dyeing. Michel Garcia refers to adding lime water in both of the first DVDs: Colors of Provence and Colors of the Americas. The specific information can be found in the dvd notes but there is no reference to the pH. Stoney Creek Colors does not add any lime in the extraction process.

      1. thanks for your reply! i am starting on a mini extraction- and saw an article that suggests .75gr per gallon- so that is not a lot of lime! as Michel Garcia mentioned in a class i took- little more than too much!.. now i will wait and see if i get some blue gold out of my leaves 🙂

        best regards,

      2. Good luck in your own extraction. I’ve been experimenting with it myself for the first time. It is my understanding that only a small amount of lime is best. If it can be done without lime, that’s even better, but I think that would require a much longer oxidation process – or composting. So much to learn!

  2. Wow, I am very impressed by this report and you are privilege to have witnessed this wonderful indigo extraction process and I thank you very much to share these words and pictures with us. I grow Japanese indigo for the third summer in my small garden in the eastern townships mountain of Quebec with mitigated results, it is a cold climate. I can understand with admiration this very old ritual and culturally very precisely orchestrated process. These people have mastered this technique and keep this tradition alive despite the modern technologies and chemicals that exist. The modernity will never achieve this beauty only possible by respecting this very old process. I look forward to extract the indigo from the dried leaves of my garden sometime next fall or winter!

    1. Isabelle, I may be wrong, but I believe that the indigo pigment needs to be extracted from fresh leaves of this variety – not dried. I am not an expert at this and have very little hands on experience with extraction.

      1. Catharine, I did make some good indigo vat with dried Persicaria tinctoria leaves last year after attending a worshop where I was thought the recipe. I don’t know if it would be possible with the Strobilanthese clusia leaves. It would be for adventurer dyers to experiment!☺

      2. Isabelle, Thanks for this. I’m the first to admit that there is so much I don’t know. In fact, I’m just now trying to extract pigment from my own Persicaria tinctoria fresh leaves right now.

  3. Good morning, Catharine. Thank you. Fascinating. I ruined my first tiny harvest with too much lime (I wrote to you about it). Hoping the September (second harvest) will be more successful with my live and learn attitude. Best regards, Georganne Alex


  4. Catharine- what a wonderful report on a clearly amazing trip! So much information and great photos. AsI get ready to leave the Asheville area and move to Michigan I’m going to need to rethink my indigo dyeing. I’ll continue to look forward to your blog posts. Thank you!

  5. Thank you so much for this post. Dorothy Yuki

    On Thu, Jul 26, 2018 at 5:32 AM, Natural Dye: Experiments and Results wrote:

    > Catharine Ellis posted: “A life of natural dyeing knows no bounds. Each > year I am thrilled and delighted to increase my knowledge and understanding > of dyes and process. This year, I was privileged to participate in the > harvesting of indigo and the extraction of pigment on the i” >

  6. Nice to know Stony Creek is offering indigo for sale! Do you have any experience using the indigo paste versus the indigo powder? Are they interchangeable in a vat?

    1. I don’t. I would assume that the paste includes more water and less indigo pigment but other than that I would assume they are interchangeable. Stoney Creek is making an indigo powder.

  7. A wonderful report as usual. I always look forward to your posts. What a fascinating experience. Natural dyes and the knowledge associated with them would take a thousand+ lifetimes to learn wouldn’t it. Thank you again.

  8. pls can u explain the details methods of natural indigo fermentation : reducing agents most important to fermentation of indigo with lime . then u make cake or powder .

    1. I am not an expert on any of this. I observe, try, and learn. Natural Dyes by Dominique Cardon includes great descriptions of the different approaches to extracting pigment and dyeing. I do think the best approach is to learn from someone who does it and understands what they are doing.

  9. Hello Catherine, I enjoyed reading about your adventure in Okinawa. I’m a 4th generation indigo practitioner and Ryukyu Kasuri weaver from Okinawa, Japan. My family hails from Izumi Village (Yanbaru forest) on northern Okinawa Island where they were known for Ryukyu Ai (indigo) dyeing, and for their bashofu (banana fiber) weaving. I’ve been growing Ryukyu Ai in Houston, TX (I now live in the U.S.) for 10 years. This semi-tropical variety of indigo (strobilanthes cusia) thrives in a hot & humid climate, so I’m able to extract indigo pigment (10% avg. production) 2x/year during the Spring and Fall. I find that my plants are more productive in the late Spring during hot & humid conditions. Although I ordinarily produce doro ai (indigo mud) to use for my fermented indigo vats, I also produce indigo powder for my artwork and for teaching. Just last week, I taught a Ryukyu Ai plant to textile workshop near Austin, TX for a group of people from Okinawa who now reside in the U.S. The Ryukyu textile culture has been deeply embedded in our heritage since the 14th century, so what better way to “reconnect” than to share blue*ti*ful moments? Thank you so much for your post! Happy weaving and dyeing 🙂

    1. So good to hear your own story about indigo and Okinawa. Thanks for taking the time to introduce yourself. I do hope that our paths cross at some point. Maybe one day I’ll have a chance to do indigo extraction with you.

  10. Hi Catherine, Thank you for sharing this inspiring information. Your post on mordants is also helpful. I just spent the past year in Japan learning about natural fibers and dyes there. Post on this here: and instagram: @auzette What other online/resources do you recommend for natural fibers and dye practices. I will check out your book. I’m sure I will have more questions for you at some point. Until then take care and stay in touch.

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