Navigation Menu+

saving seeds

Posted on Nov 4, 2010 by in gardening, indigo, natural dyes | 23 comments

Now that some of the flowers on my indigo plants (Polygonum tinctorium) have become faded and dry, I am beginning the process of saving seed for next year’s crop. First I start by cutting off the dry brown flower clusters and storing them in a paper bag for a few days to dry further. Because we have had some early rains which make the seeds moist, (and because the birds seem to love eating my indigo seeds), I have also cut some of the stems where the flowers are not yet completely dry, and am hanging them to dry inside a paper bag.

dry flower clusters from Polygonum tinctorium

Next I pick the dried flowers off the stems and place them in a large metal kitchen strainer. You can also use an old window screen, as long as the screen is fine enough to keep the seed from falling through.

dried indigo flowers in a kitchen strainer held in a glass bowl

Then I just rub the dry flowers against the strainer so that the husk around the seeds is gradually removed and the little black seeds are released. Some of the chaff falls through the screen, so I add that, plus the old stems, to my compost pile.

small black seeds from indigo (Polygonum tinctorium)

Then I put the contents of the strainer on a large plate and blow softly to remove more of the chaff, but keep the seeds. This is a bit tricky to do, as the seeds often blow away too, so I end up separating the seeds from the remaining chaff by hand.

I noticed that some of the seeds are still green, so these I will not keep, as I want to make sure I am only using the viable mature seed. I will try storing my seeds in a cool, dry place, in both a jar and an envelope, to see if one storage method works better than the other. Seeds from Polygonum tinctorium are good only if they are used for the next growing season, and cannot be stored longer.

Here’s the resource page of Richmond Grows Seed Saving Library if you want to learn more about saving seeds in general. And here is a beautiful and information-filled booklet about seed saving from the School Garden Program at Occidental Arts and Ecology Center.

When I have finished processing all my indigo seed, I would be happy to share it. Leave a comment if you want me to send you some seeds and then we can talk via email about where to send them.

I look forward to another crop next summer, with further experiments in indigo dyeing with some of the other methods I have recently learned.

Many thanks to the bees who were busy pollinating the indigo flowers this summer.


  1. Hi Dustin,
    Thanks for describing your method! I’m currently keeping the flowering stems in a vase and once in a while rub or shake them and collect the seeds that drop. Then I winnow them like you. I came across this page about seed saving and it seems to imply that one should dry the seeds as well to make them keep better. I’m doing it with a batch to see what happens but I wonder if it’s really necessary for all seeds? Do you have any experience with that?

    • Hi Eva,
      I haven’t done any extra drying to seeds that I have saved, but I have only saved seeds from plants that form pods or seed heads. It could be that it’s a necessary step for seeds contained in wet, fleshy material, like tomatoes, although the website you mention implies it’s necessary with all seeds. Something I read suggested using silica gel in seed jars to desiccate moisture. Probably the little silica packets that come in vitamin bottles would work for that, but silica gel can likely be purchased as well. When we talked about seed saving in Rebecca’s class, she didn’t mention doing anything beyond drying the seeds on the stems, and the seeds I got from her this spring were excellent! I’ll be interested to hear how the drying method works for you, and if you find those seeds more viable than seeds not dried in that manner.

  2. I am trying to gather info on growing indigo and didn’t realize it would be so hard to find seeds for it. How did you do on gathering your own? Do you still have some available for sale or sharing? Very interesting post. I want to grow it for dyeing purposes as I spin/work with wools. Thanks.

    • Hi Cindy, I was able to gather quite a few seeds from my Japanese indigo, and I would be happy to send you some. I’ll get in touch with you via your email address so you can let me know where to mail them.

  3. Hi Dustin – I would love to grow some Japanese Indigo seeds if you still have some…Thanks! Ellen

    • Hi Ellen, I still have seeds and will email you directly for your mailing address.

  4. Hello! I knew about you through Tinctory’s blog. I would love to grow Japanese Indigo and was wondering if you have seeds available. Thanks!

    • Hi Lola, After sending out several packets of seeds, I gave my remaining seeds to Rebecca Burgess, who is planting an acre of indigo this year! I’ll check with her to see if she has some seeds left, and let you know.

  5. Thank you! I will keep my fingers crossed. 🙂

    • Just found out that Rebecca has plenty of seeds, so I’ll contact you by email to get your snail mail address, Lola. By the way, I visited your blog and enjoyed seeing your creations!

  6. Thanks a lot for your help and for visiting my blog! 🙂

  7. It’s Fall, 2011 and a new season for seed harvesting. Dustin, will you be offering polygonum tinctorium seeds for sharing again this 2011 seed season? If you will be having seeds available I am interested! Thanks.

    • Hi Dianne,
      My Polygonum tinctorium plants are producing many seeds this year and I am in the process of harvesting them. My plan is to make them available through the Fibershed Marketplace, which will be launching on November 1st! The marketplace will support the farmers and artisans of Fibershed, a group that is working towards building a local textile economy with fibers and dyes from our area. The price will be $5.00 for a packet of 100 seeds and growing instructions, plus $1.50 for shipping and handling. So, please visit the Fibershed Marketplace once it’s up and running November 1st. Thanks.

  8. FIBERSHED sounds like a fantastic project! I applaud the efforts of one and all involved and I look forward to the November 1 website launch. I am excited about the availability of the polygonum tinctorium seeds and I can’t wait to place my order. THANKS!

  9. I would love some indigo seeds if you have extras . I have wanted to try indigo dying for a long time.

    • Hi Karen, July is late in the season to plant indigo, as the first harvest is now happening. I will be collecting seeds from my plants in the fall, and offering them through the Fibershed Marketplace. I recommend planting your seeds early next year, a few weeks before the last frost in your area.

  10. Very informative about saving seeds. We are starting a Maine fibershed, and I am excited about growing indigo. My plants are blooming now, and I hope to save the seeds.
    Thank you very much.

    • Good luck, Marty! Glad to hear you are starting a Maine fibershed.

  11. I’m new to this so my question may seem dumb….it’s mid-September now, and I realize I missed the first harvest, but can I harvest the seeds and the leaves at the same time? I thought the seeds needed to dry on the plant before harvesting…so I wondered then how I’d get the leaves (and keep flowers intact)? Thanks for any help!

    • Hi Judy, You are correct that the seeds need to mature and dry on the plant before harvesting. If you want to use leaves for dye while the flowers are still blooming (and you want to collect seeds later), one solution that I have used is to cut the leaves from the plant one by one, leaving at least a few leaves so that the plant can survive. Or, since each stem produces quite a few seeds, you could cut off some of the stems that are flowering to obtain your dye bath leaves, and leave a few stems for seed production. Depends how many seeds you want to harvest. Hope that helps.

      • Dustin, thank you so much for your informative reply! Your explanation helped me so much so figure out how to dye now and harvest seeds later!


        • Wonderful!

  12. I was lucky to have my Japanese indigo seed grow after 2 years. I purchased the seeds for 2014, but wasn’t able to get the seeds planted. So I was very happy they sprouted for me in 2015. I can’t remember the percentage that sprouted, but enough that I could plant several and now save plenty of seed this year.