Picture of Growing Blue
The allure of indigo has always fascinated me. I've purchased blue powder and dyed yarns in the past, but always wanted to do some batik fabrics. This was the year. And to actually grow the plants that will produce the color blue. Blue is elusive in the plant world, a few flowers like forget-me-nots or hydrangeas are blue, but you can not extract a blue dye from them. There are several plants that contain the chemical indican from which you can produce a blue dye. They include woad, dyer's knotweed,  Indigo tinctoria, and I. suifruticosa.  I planted dyer's knotweed (polygonum tinctorium), as it was the easiest to obtain seed, and also to grow in my area of the Midwest. 

Remove these adsRemove these ads by Signing Up

Step 1: Planting and growing

Picture of Planting and growing
I ordered seeds from an indigo project undertaken by Rowland Ricketts at Indiana University. I started the seeds indoors under florescent lights as they require a long growing season. It has definitely been that, this year, but one never knows. (We still have not had a frost the middle of October.) Because of a late wet and cold spring I did not plant them into the ground until the beginning of June. They grew well in my organic plot at the community garden. I perhaps planted them too close together, but they produced more than I needed for my first year of experimentation. 

Step 2: Harvesting the plants

Picture of Harvesting the plants
knotweed branches.jpg
withered leaves.jpg
The information I read said to pick them in the August or September, when the leaves are starting to show a blue tint from crushing or insect damage. I cut a few plants and let them wither to see what would happen. Yep...starting to look blue!
cookery (author) 7 months ago

In step 3. After you strain the leaves out of the pot. Add the color remover and stir gently until it is dissolved. I let it sit for about 30 minutes to an hour for the reduction to take place.You can dip the yarn/cloth at this point, or I have let it sit for a day, and then warmed it up to to about 100 degrees before dipping. (I just did it again last week with this years' crop. Did you grow it?)

1chelseA7 months ago

At what step do you add the color remover?

nah8910 months ago

When you say to cover do you mean just covering leaves or to the top of the pot?

cookery (author)  nah8910 months ago
The water should be deep enough to cover the leaves. You do not have to put a cover on the pot.
lauraabcd1 year ago
Qué lindo el proceso que hiciste , fantástico
cookery (author)  lauraabcd1 year ago
Thank you!
crazyg1 year ago
grow your own dye, impressive !
cookery (author)  crazyg1 year ago
Growing and using indigo was so exciting. Green leaves to blue dye. Just amazing. Give it a try!
I dye all my wool with lapis :)
cookery (author)  LaffyDuck1871 year ago
Where do you get it? How do you do it?
oh just a harmless minecraft reference. In minecraft, you dye wool blue by combining a lapis lazuli ore with a wool block
cookery (author)  LaffyDuck1871 year ago
oh...that's too easy...a click and it's done!
lazybird191 year ago
I think it would be cool to grow some but it's is easier to get my hand on some woad. It is an invasive species and is taking over some very big plots of land here in Utah.
cookery (author)  lazybird191 year ago
I grew some woad too. I did not have much luck with it. This dyer's knotweed seemed to have more indican in it. If it grows wild, definitely give it a try. I don't see it around here.
GemFOX1 year ago
Thank you SO much for sharing this. I have been dying for a natural dye for the cotton I grow on my patio here in the south. I can grow the indigo right next to my cotton, how cool. I have a small collection aizome fabrics from Japan and would love to make my own. Thanks and great 'ible. Your results are stunning and inspiring! Do you have any indigo seeds for sale?
cookery (author)  GemFOX1 year ago
How exciting to grow cotton! The beauty of indigo is that it works on all natural fibers and doesn't have to be boiled like other natural dyes. I'm hoping to use it on linen soon. I wish I had thought ahead enough to save more seed, but only have enough for my small plot. Maybe next year. Glad you enjoyed the 'ible!
GemFOX cookery1 year ago
Yeah I've been trying to find ways to dye my cotton balls before spinning, without mordant or commercial dyes. So I've been looking at turmeric, saffron, ochre, onion, and straight up iron oxide, all of which are in the yellow and orange tones and not the easiest to obtain. Growing indigo will make the pigment practically free and I love gardening so this is perfect. I can't wait to get my hands on some seed and try it. Thank you so much!
cookery (author)  GemFOX1 year ago
I grew a few other dye plants in my little plot this year also. The most rewarding were weld (a very clear yellow) and dyer's coreopsis (which produced a rich rust color with varying shades of peach in lesser proportions) I over-dyed the weld dyed wool with indigo and got an interesting green. So many possibilities! Today we have snow flakes, so my gardening days are over for a few months...
So cool how it changes colour as it oxidizes!

You might try cooking the leaves in a crock pot so you could keep it going all night (assuming longer simmering time = stronger dye, which might not be true.)
cookery (author)  jjdebenedictis1 year ago
A crock pot is a great idea--less watching the pot. You have to have a dedicated pot, as you don't want to mix food with craft ware. Will have to go to some yard sales and find one cheap. I don't think longer time simmering would produce more dye. There's only so much pigment in the leaves. I know I will do a lot more experimenting next summer! It was so much fun.
If you go to your local grocery store and look with aluminium foil and wax paper they might have crock pot liners. We use them since our crock finish has deteriorated over the years. It would keep you from having to add another crock pot to your collection of kitchenware.
cookery (author)  ljackson1 year ago
Good idea...I'll check that out. Thanks!
rof1 year ago
Investigating my sources of seeds I find that the polygonum is now known as persicaria tinctoria. You'll get them here.

cookery (author)  rof1 year ago
Thanks so much! I love this international community!
1chelseA1 year ago
Very cool! Where can I get the seed for this at??
cookery (author)  1chelseA1 year ago
Send a request to Rowland at the Indiana University link and he will let you know when they are available in the spring.
Do you have an email or snailmail address for Mr. Rowland?
cookery (author)  keith152291 year ago
In the Indiana University link I gave in the article there is a contact: See other comments for a source of seed from Companion Plants. I have purchased seeds and plants from them in the past.
oookdg1 year ago
So incredibly cool! You did a beautiful job with the explanation and the photos. Inspiring. I will be looking for some seeds. And looking forward!
Seed for dyer's knotweed is also available here>>
cookery (author) 1 year ago
I used polygonum tinctorium, dyer's knotweed, from Japan. I looked up Japanese knotweed, and see a big difference. Thanks for the clarification. I'll edit the text. Thanks!!!
what species of plant did are you using? The plants in your pictures do not match the plants that I know as japanese knotweed. (a very tall weed around here) and google image search didn't clarify it for me either.
This is so awesome - I've always wanted to try this. Now I'll have a much easier time, thanks to your instructions. :) I love your blog, too.
cookery (author)  supersoftdrink1 year ago
You are welcome. Thanks!!
PaganRaven1 year ago
Absolutely beautiful! And such patience! I would have been so antsy waiting on the plants to grow to then do the dying. Very well written too - I might give this a go come spring.
cookery (author)  PaganRaven1 year ago
Thanks! It was very exciting to see the colors change into blue.
Cool! Thanks for the share.
cookery (author)  audreyobscura1 year ago
You're welcome. It was a fun project.